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Revealing protonation states and tracking substrate in serine hydroxymethyltransferase with room-temperature X-ray and neutron crystallography | Communications Chemistry
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Some PLP-dependent enzymes, such as serine hydroxymethyltransferase (SHMT), are promising drug targets for the design of small-molecule antimicrobials and anticancer therapeutics, while others have been used to synthesize pharmaceutical building blocks. Understanding PLP-dependent catalysis and the reaction specificity is crucial to advance structure-assisted drug design and enzyme engineering. Here we report the direct determination of the protonation states in the active site of Thermus thermophilus SHMT (TthSHMT) in the internal aldimine state using room-temperature joint X-ray/neutron crystallography. Conserved active site architecture of the model enzyme TthSHMT and of human mitochondrial SHMT (hSHMT2) were compared by obtaining a room-temperature X-ray structure of hSHMT2, suggesting identical protonation states in the human enzyme. The amino acid substrate serine pathway through the TthSHMT active site cavity was tracked, revealing the peripheral and cationic binding sites that correspond to the pre-Michaelis and pseudo-Michaelis complexes, respectively. At the peripheral binding site, the substrate is bound in the zwitterionic form. By analyzing the observed protonation states, Glu53, but not His residues, is proposed as the general base catalyst, orchestrating the retro-aldol transformation of L-serine into glycine. Serine hydroxymethyltransferase (SHMT) is a pyridoxal 5’-phosphate (PLP)-dependent enzyme and a promising drug target, however, PLP-dependent catalysis remains underexplored. Here, the authors report joint X-ray/neutron structures of Thermus thermophilus SHMT in the internal aldimine state and in complex with L-serine substrate trapped at the peripheral binding site, revealing positions of hydrogen atoms, assigning the protonation states and electrical charges of residues, and proposing a catalytic mechanism.","datePublished":"2023-08-03T00:00:00Z","dateModified":"2023-08-03T00:00:00Z","pageStart":"1","pageEnd":"14","license":"http://creativecommons.org/licenses/by/4.0/","sameAs":"https://doi.org/10.1038/s42004-023-00964-9","keywords":["Biophysical chemistry","Enzyme mechanisms","Transferases","X-ray crystallography","Chemistry/Food Science","general"],"image":["https://media.springernature.com/lw1200/springer-static/image/art%3A10.1038%2Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig1_HTML.png","https://media.springernature.com/lw1200/springer-static/image/art%3A10.1038%2Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig2_HTML.png","https://media.springernature.com/lw1200/springer-static/image/art%3A10.1038%2Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig3_HTML.png","https://media.springernature.com/lw1200/springer-static/image/art%3A10.1038%2Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig4_HTML.png","https://media.springernature.com/lw1200/springer-static/image/art%3A10.1038%2Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig5_HTML.png"],"isPartOf":{"name":"Communications Chemistry","issn":["2399-3669"],"volumeNumber":"6","@type":["Periodical","PublicationVolume"]},"publisher":{"name":"Nature Publishing Group UK","logo":{"url":"https://www.springernature.com/app-sn/public/images/logo-springernature.png","@type":"ImageObject"},"@type":"Organization"},"author":[{"name":"Victoria N. 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Some PLP-dependent enzymes, such as serine hydroxymethyltransferase (SHMT), are promising drug targets for the design of small-molecule antimicrobials and anticancer therapeutics, while others have been used to synthesize pharmaceutical building blocks. Understanding PLP-dependent catalysis and the reaction specificity is crucial to advance structure-assisted drug design and enzyme engineering. Here we report the direct determination of the protonation states in the active site of Thermus thermophilus SHMT (TthSHMT) in the internal aldimine state using room-temperature joint X-ray/neutron crystallography. Conserved active site architecture of the model enzyme TthSHMT and of human mitochondrial SHMT (hSHMT2) were compared by obtaining a room-temperature X-ray structure of hSHMT2, suggesting identical protonation states in the human enzyme. The amino acid substrate serine pathway through the TthSHMT active site cavity was tracked, revealing the peripheral and cationic binding sites that correspond to the pre-Michaelis and pseudo-Michaelis complexes, respectively. At the peripheral binding site, the substrate is bound in the zwitterionic form. By analyzing the observed protonation states, Glu53, but not His residues, is proposed as the general base catalyst, orchestrating the retro-aldol transformation of L-serine into glycine. Serine hydroxymethyltransferase (SHMT) is a pyridoxal 5’-phosphate (PLP)-dependent enzyme and a promising drug target, however, PLP-dependent catalysis remains underexplored. Here, the authors report joint X-ray/neutron structures of Thermus thermophilus SHMT in the internal aldimine state and in complex with L-serine substrate trapped at the peripheral binding site, revealing positions of hydrogen atoms, assigning the protonation states and electrical charges of residues, and proposing a catalytic mechanism."> <meta name="prism.issn" content="2399-3669"> <meta name="prism.publicationName" content="Communications Chemistry"> <meta name="prism.publicationDate" content="2023-08-03"> <meta name="prism.volume" content="6"> <meta name="prism.number" content="1"> <meta name="prism.section" content="OriginalPaper"> <meta name="prism.startingPage" content="1"> <meta name="prism.endingPage" content="14"> <meta name="prism.copyright" content="2023 This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply"> <meta name="prism.rightsAgent" content="journalpermissions@springernature.com"> <meta name="prism.url" content="https://www.nature.com/articles/s42004-023-00964-9"> <meta name="prism.doi" content="doi:10.1038/s42004-023-00964-9"> <meta name="citation_pdf_url" content="https://www.nature.com/articles/s42004-023-00964-9.pdf"> <meta name="citation_fulltext_html_url" content="https://www.nature.com/articles/s42004-023-00964-9"> <meta name="citation_journal_title" content="Communications Chemistry"> <meta name="citation_journal_abbrev" content="Commun Chem"> <meta name="citation_publisher" content="Nature Publishing Group"> <meta name="citation_issn" content="2399-3669"> <meta name="citation_title" content="Revealing protonation states and tracking substrate in serine hydroxymethyltransferase with room-temperature X-ray and neutron crystallography"> <meta name="citation_volume" content="6"> <meta name="citation_issue" content="1"> <meta name="citation_online_date" content="2023/08/03"> <meta name="citation_firstpage" content="1"> <meta name="citation_lastpage" content="14"> <meta name="citation_article_type" content="Article"> <meta name="citation_fulltext_world_readable" content=""> <meta name="citation_language" content="en"> <meta name="dc.identifier" content="doi:10.1038/s42004-023-00964-9"> <meta name="DOI" content="10.1038/s42004-023-00964-9"> <meta name="size" content="298294"> <meta name="citation_doi" content="10.1038/s42004-023-00964-9"> <meta name="citation_springer_api_url" content="http://api.springer.com/xmldata/jats?q=doi:10.1038/s42004-023-00964-9&api_key="> <meta name="description" content="Pyridoxal 5’-phosphate (PLP)-dependent enzymes utilize a vitamin B6-derived cofactor to perform a myriad of chemical transformations on amino acids and other small molecules. Some PLP-dependent enzymes, such as serine hydroxymethyltransferase (SHMT), are promising drug targets for the design of small-molecule antimicrobials and anticancer therapeutics, while others have been used to synthesize pharmaceutical building blocks. Understanding PLP-dependent catalysis and the reaction specificity is crucial to advance structure-assisted drug design and enzyme engineering. Here we report the direct determination of the protonation states in the active site of Thermus thermophilus SHMT (TthSHMT) in the internal aldimine state using room-temperature joint X-ray/neutron crystallography. Conserved active site architecture of the model enzyme TthSHMT and of human mitochondrial SHMT (hSHMT2) were compared by obtaining a room-temperature X-ray structure of hSHMT2, suggesting identical protonation states in the human enzyme. The amino acid substrate serine pathway through the TthSHMT active site cavity was tracked, revealing the peripheral and cationic binding sites that correspond to the pre-Michaelis and pseudo-Michaelis complexes, respectively. At the peripheral binding site, the substrate is bound in the zwitterionic form. By analyzing the observed protonation states, Glu53, but not His residues, is proposed as the general base catalyst, orchestrating the retro-aldol transformation of L-serine into glycine. Serine hydroxymethyltransferase (SHMT) is a pyridoxal 5’-phosphate (PLP)-dependent enzyme and a promising drug target, however, PLP-dependent catalysis remains underexplored. Here, the authors report joint X-ray/neutron structures of Thermus thermophilus SHMT in the internal aldimine state and in complex with L-serine substrate trapped at the peripheral binding site, revealing positions of hydrogen atoms, assigning the protonation states and electrical charges of residues, and proposing a catalytic mechanism."> <meta name="dc.creator" content="Drago, Victoria N."> <meta name="dc.creator" content="Campos, Claudia"> <meta name="dc.creator" content="Hooper, Mattea"> <meta name="dc.creator" content="Collins, Aliyah"> <meta name="dc.creator" content="Gerlits, Oksana"> <meta name="dc.creator" content="Weiss, Kevin L."> <meta name="dc.creator" content="Blakeley, Matthew P."> <meta name="dc.creator" content="Phillips, Robert S."> <meta name="dc.creator" content="Kovalevsky, Andrey"> <meta name="dc.subject" content="Biophysical chemistry"> <meta name="dc.subject" content="Enzyme mechanisms"> <meta name="dc.subject" content="Transferases"> <meta name="dc.subject" content="X-ray crystallography"> <meta name="citation_reference" content="citation_journal_title=Annu Rev. Biochem; citation_title=Pyridoxal phosphate enzymes: mechanistic, structural, and evolutionary considerations; citation_author=AC Eliot, JF Kirsch; citation_volume=73; citation_publication_date=2004; citation_pages=383-415; citation_doi=10.1146/annurev.biochem.73.011303.074021; citation_id=CR1"> <meta name="citation_reference" content="citation_journal_title=Front Mol. Biosci.; citation_title=Current advances on structure-function relationships of pyridoxal 5’-phosphate-dependent enzymes; citation_author=J Liang, Q Han, Y Tan, H Ding, J Li; citation_volume=6; citation_publication_date=2019; citation_pages=4; citation_doi=10.3389/fmolb.2019.00004; citation_id=CR2"> <meta name="citation_reference" content="citation_journal_title=Protein Sci.; citation_title=Modeling of the Spatial Structure of Eukaryotic Ornithine Decarboxylases; citation_author=NV Grishin, MA Phillips, EJ Goldsmith; citation_volume=4; citation_publication_date=1995; citation_pages=1291-1304; citation_doi=10.1002/pro.5560040705; citation_id=CR3"> <meta name="citation_reference" content="citation_journal_title=Curr. Opin. Struct. Biol.; citation_title=Structure, evolution and action of vitamin B6-dependent enzymes; citation_author=JN Jansonius; citation_volume=8; citation_publication_date=1998; citation_pages=759-769; citation_doi=10.1016/S0959-440X(98)80096-1; citation_id=CR4"> <meta name="citation_reference" content="citation_journal_title=EMBO Rep.; citation_title=A genomic overview of pyridoxal-phosphate-dependent enzymes; citation_author=R Percudani, A Peracchi; citation_volume=4; citation_publication_date=2003; citation_pages=850-854; citation_doi=10.1038/sj.embor.embor914; citation_id=CR5"> <meta name="citation_reference" content="citation_journal_title=Curr. Med Chem.; citation_title=Pyridoxal 5’-phosphate enzymes as targets for therapeutic agents; citation_author=A Amadasi; citation_volume=14; citation_publication_date=2007; citation_pages=1291-1324; citation_doi=10.2174/092986707780597899; citation_id=CR6"> <meta name="citation_reference" content="citation_journal_title=Biotechnol. Adv.; citation_title=Bioinformatic analysis of a PLP-dependent enzyme superfamily suitable for biocatalytic applications; citation_author=F Steffen-Munsberg; citation_volume=33; citation_publication_date=2015; citation_pages=566-604; citation_doi=10.1016/j.biotechadv.2014.12.012; citation_id=CR7"> <meta name="citation_reference" content="citation_journal_title=Proc. Natl Acad. Sci. USA; citation_title=Conformation and reaction specificity in pyridoxal phosphate enzymes; citation_author=HC Dunathan; citation_volume=55; citation_publication_date=1966; citation_pages=712; citation_doi=10.1073/pnas.55.4.712; citation_id=CR8"> <meta name="citation_reference" content="citation_journal_title=Curr. Opin. Chem. Biol.; citation_title=Pyridoxal 5 ’-phosphate: electrophilic catalyst extraordinaire; citation_author=JP Richard, TL Amyes, J Crugeiras, A Rios; citation_volume=13; citation_publication_date=2009; citation_pages=475-483; citation_doi=10.1016/j.cbpa.2009.06.023; citation_id=CR9"> <meta name="citation_reference" content="citation_journal_title=Biochim Biophys. Acta; citation_title=Controlling reaction specificity in pyridoxal phosphate enzymes; citation_author=MD Toney; citation_volume=1814; citation_publication_date=2011; citation_pages=1407-1418; citation_doi=10.1016/j.bbapap.2011.05.019; citation_id=CR10"> <meta name="citation_reference" content="citation_journal_title=Adv. Enzymol. Ramb; citation_title=Serine Hydroxymethyltransferase; citation_author=L Schirch; citation_volume=53; citation_publication_date=1982; citation_pages=83-112; citation_id=CR11"> <meta name="citation_reference" content="citation_journal_title=Biochemistry; citation_title=Studies of reactions of lamb liver serine hydroxymethylase with l-phenylalanine - kinetic isotope effects upon quinonoid intermediate formation; citation_author=RJ Ulevitch, RG Kallen; citation_volume=16; citation_publication_date=1977; citation_pages=5350-5354; citation_doi=10.1021/bi00643a028; citation_id=CR12"> <meta name="citation_reference" content="Thomas, N. R., Schirch, V. & Gani, D. Synthesis of (2r)-[1-C-13]-2-Amino-2-Methylmalonic and (2s)-[1-C-13]-2-Amino-2-Methylmalonic Acid, Probes for the Serine Hydroxymethyltransferase Reaction - Stereospecific Decarboxylation of the 2-Pro-R Carboxy Group with the Retention of Configuration. J. Chem. Soc. Chem. Comm. 400–402, https://doi.org/10.1039/c39900000400 (1990)."> <meta name="citation_reference" content="citation_journal_title=Biochemistry; citation_title=Serine hydroxymethyltransferase: mechanism of the racemization and transamination of D- and L-alanine; citation_author=K Shostak, V Schirch; citation_volume=27; citation_publication_date=1988; citation_pages=8007-8014; citation_doi=10.1021/bi00421a006; citation_id=CR14"> <meta name="citation_reference" content="citation_journal_title=J. Biol. Chem.; citation_title=Cytoplasmic serine hydroxymethyltransferase mediates competition between folate-dependent deoxyribonucleotide and S-adenosylmethionine biosyntheses; citation_author=K Herbig; citation_volume=277; citation_publication_date=2002; citation_pages=38381-38389; citation_doi=10.1074/jbc.M205000200; citation_id=CR15"> <meta name="citation_reference" content="citation_journal_title=Invest N. Drug; citation_title=Serine hydroxymethyltransferase 2: a novel target for human cancer therapy; citation_author=M Xie, DS Pei; citation_volume=39; citation_publication_date=2021; citation_pages=1671-1681; citation_doi=10.1007/s10637-021-01144-z; citation_id=CR16"> <meta name="citation_reference" content="citation_journal_title=Biochim Biophys. Acta; citation_title=Serine hydroxymethyltransferase: a model enzyme for mechanistic, structural, and evolutionary studies; citation_author=R Florio, ML Salvo, M Vivoli, R Contestabile; citation_volume=1814; citation_publication_date=2011; citation_pages=1489-1496; citation_doi=10.1016/j.bbapap.2010.10.010; citation_id=CR17"> <meta name="citation_reference" content="citation_journal_title=FEBS J.; citation_title=How pyridoxal 5’-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state; citation_author=G Giardina; citation_volume=282; citation_publication_date=2015; citation_pages=1225-1241; citation_doi=10.1111/febs.13211; citation_id=CR18"> <meta name="citation_reference" content="citation_journal_title=Biochemistry; citation_title=Human cytosolic and mitochondrial serine hydroxymethyltransferase isoforms in comparison: full kinetic characterization and substrate inhibition properties; citation_author=A Tramonti; citation_volume=57; citation_publication_date=2018; citation_pages=6984-6996; citation_doi=10.1021/acs.biochem.8b01074; citation_id=CR19"> <meta name="citation_reference" content="citation_journal_title=J. Biol. Chem.; citation_title=Cloning of human cdnas encoding mitochondrial and cytosolic serine hydroxymethyltransferases and chromosomal localization; citation_author=TA Garrow; citation_volume=268; citation_publication_date=1993; citation_pages=11910-11916; citation_doi=10.1016/S0021-9258(19)50286-1; citation_id=CR20"> <meta name="citation_reference" content="citation_journal_title=Cell Metab.; citation_title=One-carbon metabolism in health and disease; citation_author=GS Ducker, JD Rabinowitz; citation_volume=25; citation_publication_date=2017; citation_pages=27-42; citation_doi=10.1016/j.cmet.2016.08.009; citation_id=CR21"> <meta name="citation_reference" content="citation_journal_title=Cancer Res; citation_title=Comparative oncogenomics identifies PSMB4 and SHMT2 as potential cancer driver genes; citation_author=GY Lee; citation_volume=74; citation_publication_date=2014; citation_pages=3114-3126; citation_doi=10.1158/0008-5472.CAN-13-2683; citation_id=CR22"> <meta name="citation_reference" content="citation_journal_title=FEBS J.; citation_title=The catalytic activity of serine hydroxymethyltransferase is essential for de novo nuclear dTMP synthesis in lung cancer cells; citation_author=G Giardina; citation_volume=285; citation_publication_date=2018; citation_pages=3238-3253; citation_doi=10.1111/febs.14610; citation_id=CR23"> <meta name="citation_reference" content="citation_journal_title=Mol. Cancer Res.; citation_title=Metabolic profiling reveals a dependency of human metastatic breast cancer on mitochondrial serine and one-carbon unit metabolism; citation_author=AM Li; citation_volume=18; citation_publication_date=2020; citation_pages=599-611; citation_doi=10.1158/1541-7786.MCR-19-0606; citation_id=CR24"> <meta name="citation_reference" content="citation_journal_title=Front Oncol.; citation_title=Increased expression of SHMT2 is associated with poor prognosis and advanced pathological grade in oral squamous cell carcinoma; citation_author=ZZ Wu; citation_volume=10; citation_publication_date=2020; citation_pages=588530; citation_doi=10.3389/fonc.2020.588530; citation_id=CR25"> <meta name="citation_reference" content="citation_journal_title=Drug Discov. Today; citation_title=Folate-mediated one-carbon metabolism: a targeting strategy in cancer therapy; citation_author=CC Yang; citation_volume=26; citation_publication_date=2021; citation_pages=817-825; citation_doi=10.1016/j.drudis.2020.12.006; citation_id=CR26"> <meta name="citation_reference" content="citation_journal_title=Can. J. Gastroenterol.; citation_title=SHMT2 drives the progression of colorectal cancer by regulating UHRF1 expression; citation_author=XM Cui; citation_volume=2022; citation_publication_date=2022; citation_pages=3758697; citation_id=CR27"> <meta name="citation_reference" content="citation_journal_title=J. Cancer; citation_title=Roles of mitochondrial serine hydroxymethyltransferase 2 (SHMT2) in human carcinogenesis; citation_author=Y Zeng; citation_volume=12; citation_publication_date=2021; citation_pages=5888-5894; citation_doi=10.7150/jca.60170; citation_id=CR28"> <meta name="citation_reference" content="citation_journal_title=Transl. Cancer Res; citation_title=Serine hydroxymethyltransferase 2 predicts unfavorable outcomes in multiple cancer: a systematic review and meta-analysis; citation_author=J Du; citation_volume=11; citation_publication_date=2022; citation_pages=444-455; citation_doi=10.21037/tcr-21-2485; citation_id=CR29"> <meta name="citation_reference" content="citation_journal_title=Cell Rep.; citation_title=SHMT2-mediated mitochondrial serine metabolism drives 5-FU resistance by fueling nucleotide biosynthesis; citation_author=E Pranzini; citation_volume=40; citation_publication_date=2022; citation_pages=111233; citation_doi=10.1016/j.celrep.2022.111233; citation_id=CR30"> <meta name="citation_reference" content="citation_journal_title=Oncotarget; citation_title=Induction of serine hydroxymethyltransferase 2 promotes tumorigenesis and metastasis in neuroblastoma; citation_author=RA Clark, J Qiao, JC Jacobson, DH Chung; citation_volume=13; citation_publication_date=2022; citation_pages=32-45; citation_doi=10.18632/oncotarget.28168; citation_id=CR31"> <meta name="citation_reference" content="citation_journal_title=ACS Pharm. Transl.; citation_title=A review of small-molecule inhibitors of one-carbon enzymes: SHMT2 and MTHFD2 in the Spotlight; citation_author=CR Cuthbertson, Z Arabzada, A Bankhead, A Kyani, N Neamati; citation_volume=4; citation_publication_date=2021; citation_pages=624-646; citation_doi=10.1021/acsptsci.0c00223; citation_id=CR32"> <meta name="citation_reference" content="citation_journal_title=Nat. Rev. Drug Discov.; citation_title=Targeting cancer metabolism in the era of precision oncology; citation_author=ZE Stine, ZT Schug, JM Salvino, CV Dang; citation_volume=21; citation_publication_date=2022; citation_pages=141-162; citation_doi=10.1038/s41573-021-00339-6; citation_id=CR33"> <meta name="citation_reference" content="citation_journal_title=Chem. Biol. Drug Des.; citation_title=Identification of three new compounds that directly target human serine hydroxymethyltransferase 2; citation_author=Y Han; citation_volume=97; citation_publication_date=2021; citation_pages=221-230; citation_doi=10.1111/cbdd.13774; citation_id=CR34"> <meta name="citation_reference" content="citation_journal_title=Leukemia; citation_title=SHMT inhibition is effective and synergizes with methotrexate in T-cell acute lymphoblastic leukemia; citation_author=JC Garcia-Canaveras; citation_volume=35; citation_publication_date=2021; citation_pages=377-388; citation_doi=10.1038/s41375-020-0845-6; citation_id=CR35"> <meta name="citation_reference" content="citation_journal_title=Leukemia; citation_title=Targeting serine hydroxymethyltransferases 1 and 2 for T-cell acute lymphoblastic leukemia therapy; citation_author=Y Pikman; citation_volume=36; citation_publication_date=2022; citation_pages=348-360; citation_doi=10.1038/s41375-021-01361-8; citation_id=CR36"> <meta name="citation_reference" content="citation_journal_title=Proc. Natl Acad. Sci. USA; citation_title=Human SHMT inhibitors reveal defective glycine import as a targetable metabolic vulnerability of diffuse large B-cell lymphoma; citation_author=GS Ducker; citation_volume=114; citation_publication_date=2017; citation_pages=11404-11409; citation_doi=10.1073/pnas.1706617114; citation_id=CR37"> <meta name="citation_reference" content="citation_journal_title=J. Med Chem.; citation_title=Biotin’s lessons in drug design; citation_author=DB McConnell; citation_volume=64; citation_publication_date=2021; citation_pages=16319-16327; citation_doi=10.1021/acs.jmedchem.1c00975; citation_id=CR38"> <meta name="citation_reference" content="citation_journal_title=Proc. Natl Acad. Sci. USA; citation_title=Hydrogen atoms in proteins: positions and dynamics; citation_author=N Engler, A Ostermann, N Niimura, FG Parak; citation_volume=100; citation_publication_date=2003; citation_pages=10243-10248; citation_doi=10.1073/pnas.1834279100; citation_id=CR39"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr. Sect. D.; citation_title=Getting the chemistry right: protonation, tautomers and the importance of H atoms in biological chemistry; citation_author=B Bax, C Chung, C Edge; citation_volume=73; citation_publication_date=2017; citation_pages=131-140; citation_doi=10.1107/S2059798316020283; citation_id=CR40"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr. Sect. D.-Struct. Biol.; citation_title=Unambiguous determination of H-atom positions: comparing results from neutron and high-resolution X-ray crystallography; citation_author=AS Gardberg; citation_volume=66; citation_publication_date=2010; citation_pages=558-567; citation_doi=10.1107/S0907444910005494; citation_id=CR41"> <meta name="citation_reference" content="Niimura, N. & Podjarny, A. Neutron Protein Crystallography: Hydrogen, Protons, and Hydration in Bio-macromolecules, 232 (Oxford University Press, Oxford, UK, 2011)."> <meta name="citation_reference" content="citation_journal_title=Angew. Chem. Int Ed. Engl.; citation_title=Long-range electrostatics-induced two-proton transfer captured by neutron crystallography in an enzyme catalytic site; citation_author=O Gerlits; citation_volume=55; citation_publication_date=2016; citation_pages=4924-4927; citation_doi=10.1002/anie.201509989; citation_id=CR43"> <meta name="citation_reference" content="citation_journal_title=Nat. Commun.; citation_title=Direct visualization of critical hydrogen atoms in a pyridoxal 5’-phosphate enzyme; citation_author=S Dajnowicz; citation_volume=8; citation_publication_date=2017; citation_doi=10.1038/s41467-017-01060-y; citation_id=CR44"> <meta name="citation_reference" content="citation_journal_title=Chem. Sci.; citation_title=An N···H···N low-barrier hydrogen bond preorganizes the catalytic site of aspartate aminotransferase to facilitate the second half-reaction; citation_author=VN Drago; citation_volume=13; citation_publication_date=2022; citation_pages=10057-10065; citation_doi=10.1039/D2SC02285K; citation_id=CR45"> <meta name="citation_reference" content="citation_journal_title=J. Am. Chem. Soc.; citation_title=Neutron diffraction of acetazolamide-bound human carbonic anhydrase II reveals atomic details of drug binding; citation_author=SZ Fisher, M Aggarwal, AY Kovalevsky, DN Silverman, R McKenna; citation_volume=134; citation_publication_date=2012; citation_pages=14726-14729; citation_doi=10.1021/ja3068098; citation_id=CR46"> <meta name="citation_reference" content="citation_journal_title=J. Med. Chem.; citation_title=Joint X-ray/neutron crystallographic study of HIV-1 protease with clinical inhibitor amprenavir: insights for drug design; citation_author=IT Weber; citation_volume=56; citation_publication_date=2013; citation_pages=5631-5635; citation_doi=10.1021/jm400684f; citation_id=CR47"> <meta name="citation_reference" content="citation_journal_title=J. Med. Chem.; citation_title=Elucidation of hydrogen bonding patterns in ligand-free, lactose- and glycerol-bound galectin-3c by neutron crystallography to guide drug design; citation_author=F Manzoni; citation_volume=61; citation_publication_date=2018; citation_pages=4412-4420; citation_doi=10.1021/acs.jmedchem.8b00081; citation_id=CR48"> <meta name="citation_reference" content="citation_journal_title=J. Med Chem.; citation_title=Structural, electronic, and electrostatic determinants for inhibitor binding to subsites S1 and S2 in SARS-CoV-2 main protease; citation_author=DW Kneller; citation_volume=64; citation_publication_date=2021; citation_pages=17366-17383; citation_doi=10.1021/acs.jmedchem.1c01475; citation_id=CR49"> <meta name="citation_reference" content="Kneller, D. et al. Covalent narlaprevir- and boceprevir-derived hybrid inhibitors of SARS-CoV-2 main protease: room-temperature X-ray and neutron crystallography, binding thermodynamics, and antiviral activity. Res. Sq. https://doi.org/10.21203/rs.3.rs-1318037/v1 (2022)."> <meta name="citation_reference" content="citation_journal_title=Sci. Adv.; citation_title=Zooming in on protons: neutron structure of protein kinase a trapped in a product complex; citation_author=O Gerlits; citation_volume=5; citation_publication_date=2019; citation_pages=eaav0482; citation_doi=10.1126/sciadv.aav0482; citation_id=CR51"> <meta name="citation_reference" content="citation_journal_title=ACS Omega; citation_title=Visualizing tetrahedral oxyanion bound in HIV-1 protease using neutrons: implications for the catalytic mechanism and drug design; citation_author=M Kumar; citation_volume=5; citation_publication_date=2020; citation_pages=11605-11617; citation_doi=10.1021/acsomega.0c00835; citation_id=CR52"> <meta name="citation_reference" content="citation_journal_title=Structure; citation_title=The crystal structure of human cytosolic serine hydroxymethyltransferase: a target for cancer chemotherapy; citation_author=SB Renwick, K Snell, U Baumann; citation_volume=6; citation_publication_date=1998; citation_pages=1105-1116; citation_doi=10.1016/S0969-2126(98)00112-9; citation_id=CR53"> <meta name="citation_reference" content="citation_journal_title=J. Biol. Chem.; citation_title=Crystal structure of binary and ternary complexes of serine hydroxymethyltransferase from Bacillus stearothermophilus - Insights into the catalytic mechanism; citation_author=V Trivedi; citation_volume=277; citation_publication_date=2002; citation_pages=17161-17169; citation_doi=10.1074/jbc.M111976200; citation_id=CR54"> <meta name="citation_reference" content="citation_journal_title=Biochemistry; citation_title=Serine hydroxymethyltransferase: role of Glu75 and evidence that serine is cleaved by a retroaldol mechanism; citation_author=DME Szebenyi, FN Musayev, ML Salvo, MK Safo, V Schirch; citation_volume=43; citation_publication_date=2004; citation_pages=6865-6876; citation_doi=10.1021/bi049791y; citation_id=CR55"> <meta name="citation_reference" content="citation_journal_title=Curr. Opin. Chem. Biol.; citation_title=Serine hydroxymethyltransferase revisited; citation_author=V Schirch, DM Szebenyi; citation_volume=9; citation_publication_date=2005; citation_pages=482-487; citation_doi=10.1016/j.cbpa.2005.08.017; citation_id=CR56"> <meta name="citation_reference" content="citation_journal_title=Eur. J. Biochem; citation_title=Importance of the amino terminus in maintenance of oligomeric structure of sheep liver cytosolic serine hydroxymethyltransferase; citation_author=JR Jagath; citation_volume=247; citation_publication_date=1997; citation_pages=372-379; citation_doi=10.1111/j.1432-1033.1997.00372.x; citation_id=CR57"> <meta name="citation_reference" content="citation_journal_title=Biochim. Biophys. Acta-Proteins Proteom.; citation_title=Structure-function relationship in serine hydroxymethyltransferase; citation_author=NA Rao, M Ambili, VR Jala, HS Subramanya, HS Savithri; citation_volume=1647; citation_publication_date=2003; citation_pages=24-29; citation_doi=10.1016/S1570-9639(03)00043-8; citation_id=CR58"> <meta name="citation_reference" content="citation_journal_title=Chem. Rev.; citation_title=Providing one-carbon units for biological methylations - Mechanistic studies on serine hydroxymethyltransferase, methylenetetrahydrofolate reductase, and methyltetrahydrofolate-homocysteine methyltransferase; citation_author=RG Matthews, JT Drummond; citation_volume=90; citation_publication_date=1990; citation_pages=1275-1290; citation_doi=10.1021/cr00105a010; citation_id=CR59"> <meta name="citation_reference" content="citation_journal_title=ACS Catal.; citation_title=Catalytic mechanism of the serine hydroxymethyltransferase: a computational ONIOM QM/MM study; citation_author=HS Fernandes, MJ Ramos, NMFSA Cerqueira; citation_volume=8; citation_publication_date=2018; citation_pages=10096-10110; citation_doi=10.1021/acscatal.8b02321; citation_id=CR60"> <meta name="citation_reference" content="citation_journal_title=Nat. Commun.; citation_title=Design strategy for serine hydroxymethyltransferase probes based on retro-aldol-type reaction; citation_author=H Nonaka; citation_volume=10; citation_publication_date=2019; citation_doi=10.1038/s41467-019-08833-7; citation_id=CR61"> <meta name="citation_reference" content="citation_journal_title=FEBS Lett.; citation_title=Structural basis of inhibition of the human serine hydroxymethyltransferase SHMT2 by antifolate drugs; citation_author=E Scaletti, AS Jemth, T Helleday, P Stenmark; citation_volume=593; citation_publication_date=2019; citation_pages=1863-1873; citation_doi=10.1002/1873-3468.13455; citation_id=CR62"> <meta name="citation_reference" content="citation_journal_title=iScience; citation_title=Structural basis for selective inhibition of human serine hydroxymethyltransferase by secondary bile acid conjugate; citation_author=T Ota; citation_volume=24; citation_publication_date=2021; citation_pages=102036; citation_doi=10.1016/j.isci.2021.102036; citation_id=CR63"> <meta name="citation_reference" content="citation_journal_title=Emerg. Top. Life Sci.; citation_title=Neutron macromolecular crystallography; citation_author=MP Blakeley, AD Podjarny; citation_volume=2; citation_publication_date=2018; citation_pages=39-55; citation_doi=10.1042/ETLS20170083; citation_id=CR64"> <meta name="citation_reference" content="citation_journal_title=Structure; citation_title=The manifold of vitamin B6 dependent enzymes; citation_author=G Schneider, H Kack, Y Lindqvist; citation_volume=8; citation_publication_date=2000; citation_pages=R1-R6; citation_doi=10.1016/S0969-2126(00)00085-X; citation_id=CR65"> <meta name="citation_reference" content="citation_journal_title=J. Mol. Biol.; citation_title=Crystal structure at 2.4 Å resolution of E. coli serine hydroxymethyltransferase in complex with glycine substrate and 5-formyl tetrahydrofolate11Edited by I. A. Wilson; citation_author=JN Scarsdale, S Radaev, G Kazanina, V Schirch, HT Wright; citation_volume=296; citation_publication_date=2000; citation_pages=155-168; citation_doi=10.1006/jmbi.1999.3453; citation_id=CR66"> <meta name="citation_reference" content="citation_journal_title=Biochemistry; citation_title=Structure of a murine cytoplasmic serine hydroxymethyltransferase quinonoid ternary complex: Evidence for asymmetric obligate dimers; citation_author=DME Szebenyi, XW Liu, IA Kriksunov, PJ Stover, DJ Thiel; citation_volume=39; citation_publication_date=2000; citation_pages=13313-13323; citation_doi=10.1021/bi000635a; citation_id=CR67"> <meta name="citation_reference" content="citation_journal_title=Chem. Phys.; citation_title=Theoretical study on the distribution of atomic charges in the Schiff bases of 3-hydroxypyridine-4-aldehyde and alanine. The effect of the protonation state of the pyridine and imine nitrogen atoms; citation_author=R Casasnovas, A Salvà, J Frau, J Donoso, F Muñoz; citation_volume=355; citation_publication_date=2009; citation_pages=149-156; citation_doi=10.1016/j.chemphys.2008.12.006; citation_id=CR68"> <meta name="citation_reference" content="citation_journal_title=J. Am. Chem. Soc.; citation_title=Role of the pyridine nitrogen in pyridoxal 5’-phosphate catalysis: activity of three classes of PLP enzymes reconstituted with deazapyridoxal 5’-phosphate; citation_author=WR Griswold, MD Toney; citation_volume=133; citation_publication_date=2011; citation_pages=14823-14830; citation_doi=10.1021/ja2061006; citation_id=CR69"> <meta name="citation_reference" content="citation_journal_title=Methods Enzymol.; citation_title=Pyridoxal 5’-phosphate dependent reactions: analyzing the mechanism of aspartate aminotransferase; citation_author=TC Mueser, V Drago, A Kovalevsky, S Dajnowicz; citation_volume=634; citation_publication_date=2020; citation_pages=333-359; citation_doi=10.1016/bs.mie.2020.01.009; citation_id=CR70"> <meta name="citation_reference" content="citation_journal_title=J. Phys. Chem. B; citation_title=C-H Activation in Pyridoxal-5 ’-phosphate Schiff bases: the role of the imine nitrogen. A combined experimental and computational study; citation_author=R Casasnovas; citation_volume=116; citation_publication_date=2012; citation_pages=10665-10675; citation_doi=10.1021/jp303678n; citation_id=CR71"> <meta name="citation_reference" content="citation_journal_title=FEBS J.; citation_title=Structure determination and biochemical studies on Bacillus stearothermophilus E53Q serine hydroxymethyltransferase and its complexes provide insights on function and enzyme memory; citation_author=V Rajaram; citation_volume=274; citation_publication_date=2007; citation_pages=4148-4160; citation_doi=10.1111/j.1742-4658.2007.05943.x; citation_id=CR72"> <meta name="citation_reference" content="citation_journal_title=Proc. Natl Acad. Sci. USA; citation_title=Intracellular Cl- as a signaling ion that potently regulates Na+/HCO3- transporters; citation_author=N Shcheynikov; citation_volume=112; citation_publication_date=2015; citation_pages=E329-E337; citation_doi=10.1073/pnas.1415673112; citation_id=CR73"> <meta name="citation_reference" content="citation_journal_title=Biochem. Biophys. Res Commun.; citation_title=Chloride concentrations in human hepatic cytosol and mitochondria are a function of age; citation_author=SC Jahn, L Rowland-Faux, PW Stacpoole, MO James; citation_volume=459; citation_publication_date=2015; citation_pages=463-468; citation_doi=10.1016/j.bbrc.2015.02.128; citation_id=CR74"> <meta name="citation_reference" content="citation_journal_title=Biochemistry; citation_title=Modulation of the internal aldimine pK(a)’s of 1-aminocyclopropane-1-carboxylate synthase and aspartate arninotransferase by specific active site residues; citation_author=AC Eliot, JF Kirsch; citation_volume=41; citation_publication_date=2002; citation_pages=3836-3842; citation_doi=10.1021/bi016084l; citation_id=CR75"> <meta name="citation_reference" content="citation_journal_title=Sci. Rep.-UK; citation_title=Structural basis of methotrexate and pemetrexed action on serine hydroxymethyltransferases revealed using plant models; citation_author=M Ruszkowski; citation_volume=9; citation_publication_date=2019; citation_pages=19614; citation_doi=10.1038/s41598-019-56043-4; citation_id=CR76"> <meta name="citation_reference" content="citation_journal_title=Commun. Biol.; citation_title=Serine hydroxymethyltransferase as a potential target of antibacterial agents acting synergistically with one-carbon metabolism-related inhibitors; citation_author=Y Makino; citation_volume=5; citation_publication_date=2022; citation_pages=619; citation_doi=10.1038/s42003-022-03555-x; citation_id=CR77"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr D.; citation_title=Structures of Plasmodium vivax serine hydroxymethyltransferase: implications for ligand-binding specificity and functional control; citation_author=P Chitnumsub; citation_volume=70; citation_publication_date=2014; citation_pages=3177-3186; citation_doi=10.1107/S1399004714023128; citation_id=CR78"> <meta name="citation_reference" content="citation_journal_title=Front Plant Sci.; citation_title=Chloroplastic serine hydroxymethyltransferase from medicago truncatula: a structural characterization; citation_author=M Ruszkowski, B Sekula, A Ruszkowska, Z Dauter; citation_volume=9; citation_publication_date=2018; citation_pages=584; citation_doi=10.3389/fpls.2018.00584; citation_id=CR79"> <meta name="citation_reference" content="citation_journal_title=Biochemistry; citation_title=Mannobiose binding induces changes in hydrogen bonding and protonation states of acidic residues in concanavalin a as revealed by neutron crystallography; citation_author=OO Gerlits, L Coates, RJ Woods, A Kovalevsky; citation_volume=56; citation_publication_date=2017; citation_pages=4747-4750; citation_doi=10.1021/acs.biochem.7b00654; citation_id=CR80"> <meta name="citation_reference" content="citation_journal_title=J. Med. Chem.; citation_title=Room temperature neutron crystallography of drug resistant HIV-1 protease uncovers limitations of X-ray structural analysis at 100 K; citation_author=O Gerlits; citation_volume=60; citation_publication_date=2017; citation_pages=2018-2025; citation_doi=10.1021/acs.jmedchem.6b01767; citation_id=CR81"> <meta name="citation_reference" content="citation_journal_title=Biochemistry; citation_title=Role of tyrosine 65 in the mechanism of serine hydroxymethyltransferase; citation_author=R Contestabile; citation_volume=39; citation_publication_date=2000; citation_pages=7492-7500; citation_doi=10.1021/bi000032z; citation_id=CR82"> <meta name="citation_reference" content="citation_journal_title=FEBS J.; citation_title=Mechanism for folate-independent aldolase reaction catalyzed by serine hydroxymethyltransferase; citation_author=Y Chiba; citation_volume=279; citation_publication_date=2012; citation_pages=504-514; citation_doi=10.1111/j.1742-4658.2011.08443.x; citation_id=CR83"> <meta name="citation_reference" content="citation_journal_title=J. Phys. Chem. B; citation_title=Free energy landscape and proton transfer pathways of the transimination reaction at the active site of the serine hydroxymethyltransferase enzyme in aqueous medium; citation_author=K Soniya, A Chandra; citation_volume=125; citation_publication_date=2021; citation_pages=11848-11856; citation_doi=10.1021/acs.jpcb.1c05864; citation_id=CR84"> <meta name="citation_reference" content="citation_journal_title=Biomed. Res. Int.; citation_title=Structure-based mechanism for early PLP-mediated steps of rabbit cytosolic serine hydroxymethyltransferase reaction; citation_author=ML Salvo; citation_volume=2013; citation_publication_date=2013; citation_pages=458571; citation_doi=10.1155/2013/458571; citation_id=CR85"> <meta name="citation_reference" content="citation_journal_title=Eur. J. Biochem.; citation_title=His230 of serine hydroxymethyltransferase facilitates the proton abstraction step in catalysis; citation_author=R Talwar, JR Jagath, NA Rao, HS Savithri; citation_volume=267; citation_publication_date=2000; citation_pages=1441-1446; citation_doi=10.1046/j.1432-1327.2000.01142.x; citation_id=CR86"> <meta name="citation_reference" content="citation_journal_title=Eur. J. Biochem; citation_title=The role of Glu74 and Tyr82 in the reaction catalyzed by sheep liver cytosolic serine hydroxymethyltransferase; citation_author=JVK Rao, V Prakash, NA Rao, HS Savithri; citation_volume=267; citation_publication_date=2000; citation_pages=5967-5976; citation_doi=10.1046/j.1432-1327.2000.01667.x; citation_id=CR87"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr. D. Biol. Crystallogr.; citation_title=Neutron macromolecular crystallography with LADI-III; citation_author=MP Blakeley; citation_volume=66; citation_publication_date=2010; citation_pages=1198-1205; citation_doi=10.1107/S0907444910019797; citation_id=CR88"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr. D. Biol. Crystallogr.; citation_title=The IMAGINE instrument: first neutron protein structure and new capabilities for neutron macromolecular crystallography; citation_author=F Meilleur; citation_volume=69; citation_publication_date=2013; citation_pages=2157-2160; citation_doi=10.1107/S0907444913019604; citation_id=CR89"> <meta name="citation_reference" content="citation_journal_title=Crystals; citation_title=The neutron macromolecular crystallography instruments at oak ridge national laboratory: advances, challenges, and opportunities; citation_author=F Meilleur, L Coates, MJ Cuneo, A Kovalevsky, DAA Myles; citation_volume=8; citation_publication_date=2018; citation_pages=388; citation_doi=10.3390/cryst8100388; citation_id=CR90"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr. D. Struct. Biol.; citation_title=IMAGINE: neutrons reveal enzyme chemistry; citation_author=GC Schroder, WB O’Dell, DAA Myles, A Kovalevsky, F Meilleur; citation_volume=74; citation_publication_date=2018; citation_pages=778-786; citation_doi=10.1107/S2059798318001626; citation_id=CR91"> <meta name="citation_reference" content="citation_journal_title=Methods Enzymol.; citation_title=IMAGINE: The neutron protein crystallography beamline at the high flux isotope reactor; citation_author=F Meilleur, A Kovalevsky, DAA Myles; citation_volume=634; citation_publication_date=2020; citation_pages=69-85; citation_doi=10.1016/bs.mie.2019.11.016; citation_id=CR92"> <meta name="citation_reference" content="citation_journal_title=J. Appl. Crystallogr.; citation_title=Lauegen, an X-windows-based program for the processing of Laue X-Ray-diffraction data; citation_author=JW Campbell; citation_volume=28; citation_publication_date=1995; citation_pages=228-236; citation_doi=10.1107/S002188989400991X; citation_id=CR93"> <meta name="citation_reference" content="citation_journal_title=J. Appl. Crystallogr.; citation_title=LAUEGEN version 6.0 and INTLDM; citation_author=JW Campbell, Q Hao, MM Harding, ND Nguti, C Wilkinson; citation_volume=31; citation_publication_date=1998; citation_pages=496-502; citation_doi=10.1107/S0021889897016683; citation_id=CR94"> <meta name="citation_reference" content="citation_journal_title=J. Appl. Crystallogr.; citation_title=LSCALE - the new normalization, scaling and absorption correction program in the Daresbury Laue software suite; citation_author=S Arzt, JW Campbell, MM Harding, Q Hao, JR Helliwell; citation_volume=32; citation_publication_date=1999; citation_pages=554-562; citation_doi=10.1107/S0021889898015350; citation_id=CR95"> <meta name="citation_reference" content="citation_journal_title=J. Appl. Crystallogr.; citation_title=The macromolecular neutron diffractometer MaNDi at the spallation neutron source; citation_author=L Coates; citation_volume=48; citation_publication_date=2015; citation_pages=1302-1306; citation_doi=10.1107/S1600576715011243; citation_id=CR96"> <meta name="citation_reference" content="citation_journal_title=Method Enzymol.; citation_title=The macromolecular neutron diffractometer at the spallation neutron source; citation_author=L Coates, B Sullivan; citation_volume=634; citation_publication_date=2020; citation_pages=87-99; citation_doi=10.1016/bs.mie.2019.11.020; citation_id=CR97"> <meta name="citation_reference" content="citation_journal_title=Nucl. Instrum. Methods Phys. Res. Sect. A: Accel. Spectrom. Detect. Assoc. Equip.; citation_title=Mantid—Data analysis and visualization package for neutron scattering and μ SR experiments; citation_author=O Arnold; citation_volume=764; citation_publication_date=2014; citation_pages=156-166; citation_doi=10.1016/j.nima.2014.07.029; citation_id=CR98"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr. Sect. D.-Struct. Biol.; citation_title=Improving the accuracy and resolution of neutron crystallographic data by three-dimensional profile fitting of Bragg peaks in reciprocal space; citation_author=B Sullivan; citation_volume=74; citation_publication_date=2018; citation_pages=1085-1095; citation_doi=10.1107/S2059798318013347; citation_id=CR99"> <meta name="citation_reference" content="citation_journal_title=J. Appl. Crystallogr.; citation_title=The recording and analysis of synchrotron X-radiation laue diffraction photographs; citation_author=JR Helliwell; citation_volume=22; citation_publication_date=1989; citation_pages=483-497; citation_doi=10.1107/S0021889889006564; citation_id=CR100"> <meta name="citation_reference" content="citation_journal_title=J. Appl. Crystallogr.; citation_title=Global indicators of X-ray data quality; citation_author=MS Weiss; citation_volume=34; citation_publication_date=2001; citation_pages=130-135; citation_doi=10.1107/S0021889800018227; citation_id=CR101"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr. D. Biol. Crystallogr.; citation_title=How good are my data and what is the resolution?; citation_author=PR Evans, GN Murshudov; citation_volume=69; citation_publication_date=2013; citation_pages=1204-1214; citation_doi=10.1107/S0907444913000061; citation_id=CR102"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr. Sect. D.-Struct. Biol.; citation_title=Overview of the CCP4 suite and current developments; citation_author=MD Winn; citation_volume=67; citation_publication_date=2011; citation_pages=235-242; citation_doi=10.1107/S0907444910045749; citation_id=CR103"> <meta name="citation_reference" content="citation_journal_title=J. Appl. Crystallogr.; citation_title=Phaser crystallographic software; citation_author=AJ Mccoy; citation_volume=40; citation_publication_date=2007; citation_pages=658-674; citation_doi=10.1107/S0021889807021206; citation_id=CR104"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr. D. Biol. Crystallogr.; citation_title=HKL-3000: the integration of data reduction and structure solution-from diffraction images to an initial model in minutes; citation_author=W Minor, M Cymborowski, Z Otwinowski, M Chruszcz; citation_volume=62; citation_publication_date=2006; citation_pages=859-866; citation_doi=10.1107/S0907444906019949; citation_id=CR105"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr. D. Biol. Crystallogr.; citation_title=PHENIX: a comprehensive Python-based system for macromolecular structure solution; citation_author=PD Adams; citation_volume=66; citation_publication_date=2010; citation_pages=213-221; citation_doi=10.1107/S0907444909052925; citation_id=CR106"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr. Sect. D.-Struct. Biol.; citation_title=Macromolecular structure determination using X-rays, neutrons and electrons: recent developments in Phenix; citation_author=D Liebschner; citation_volume=75; citation_publication_date=2019; citation_pages=861-877; citation_doi=10.1107/S2059798319011471; citation_id=CR107"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr. Sect. D.-Struct. Biol.; citation_title=Coot: model-building tools for molecular graphics; citation_author=P Emsley, K Cowtan; citation_volume=60; citation_publication_date=2004; citation_pages=2126-2132; citation_doi=10.1107/S0907444904019158; citation_id=CR108"> <meta name="citation_reference" content="citation_journal_title=Acta Crystallogr D. Biol. 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href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://www.springernature.com/gp/open-research/about/the-fundamentals-of-open-access-and-open-research" data-track="click" data-track-action="open access" data-track-label="link" class="u-color-open-access" data-test="open-access">Open access</a></li> <li class="c-article-identifiers__item">Published: <time datetime="2023-08-03">03 August 2023</time></li> </ul> <h1 class="c-article-title" data-test="article-title" data-article-title="">Revealing protonation states and tracking substrate in serine hydroxymethyltransferase with room-temperature X-ray and neutron crystallography</h1> <ul class="c-article-author-list c-article-author-list--short" data-test="authors-list" data-component-authors-activator="authors-list"> <li class="c-article-author-list__item"><a data-test="author-name" data-track="click" data-track-action="open author" data-track-label="link" 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authors</span></button> <p class="c-article-info-details" data-container-section="info"><a data-test="journal-link" href="https://www-nature-com.translate.goog/commschem?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track="click" data-track-action="journal homepage" data-track-category="article body" data-track-label="link"><i data-test="journal-title">Communications Chemistry</i></a> <b data-test="journal-volume"><span class="u-visually-hidden">volume</span> 6</b>, Article number: <span data-test="article-number">162</span> (<span data-test="article-publication-year">2023</span>) <a href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#citeas" class="c-article-info-details__cite-as u-hide-print" data-track="click" data-track-action="cite this article" data-track-label="link">Cite this article</a></p> <div class="c-article-metrics-bar__wrapper u-clear-both"> <ul class="c-article-metrics-bar u-list-reset"> <li class=" 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class="c-article__sub-heading">Subjects</h3> <ul class="c-article-subject-list"> <li class="c-article-subject-list__subject"><a href="https://www-nature-com.translate.goog/subjects/biophysical-chemistry?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track="click" data-track-action="view subject" data-track-label="link">Biophysical chemistry</a></li> <li class="c-article-subject-list__subject"><a href="https://www-nature-com.translate.goog/subjects/enzyme-mechanisms?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track="click" data-track-action="view subject" data-track-label="link">Enzyme mechanisms</a></li> <li class="c-article-subject-list__subject"><a href="https://www-nature-com.translate.goog/subjects/transferases?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track="click" data-track-action="view subject" data-track-label="link">Transferases</a></li> <li class="c-article-subject-list__subject"><a href="https://www-nature-com.translate.goog/subjects/x-ray-crystallography?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track="click" data-track-action="view subject" data-track-label="link">X-ray crystallography</a></li> </ul> </div> </div> <div class="c-article-body"> <section aria-labelledby="Abs1" data-title="Abstract" lang="en"> <div class="c-article-section" id="Abs1-section"> <h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Abs1">Abstract</h2> <div class="c-article-section__content" id="Abs1-content"> <p>Pyridoxal 5’-phosphate (PLP)-dependent enzymes utilize a vitamin B<sub>6</sub>-derived cofactor to perform a myriad of chemical transformations on amino acids and other small molecules. Some PLP-dependent enzymes, such as serine hydroxymethyltransferase (SHMT), are promising drug targets for the design of small-molecule antimicrobials and anticancer therapeutics, while others have been used to synthesize pharmaceutical building blocks. Understanding PLP-dependent catalysis and the reaction specificity is crucial to advance structure-assisted drug design and enzyme engineering. Here we report the direct determination of the protonation states in the active site of <i>Thermus thermophilus</i> SHMT (<i>Tth</i>SHMT) in the internal aldimine state using room-temperature joint X-ray/neutron crystallography. Conserved active site architecture of the model enzyme <i>Tth</i>SHMT and of human mitochondrial SHMT (hSHMT2) were compared by obtaining a room-temperature X-ray structure of hSHMT2, suggesting identical protonation states in the human enzyme. The amino acid substrate serine pathway through the <i>Tth</i>SHMT active site cavity was tracked, revealing the peripheral and cationic binding sites that correspond to the <i>pre</i>-Michaelis and <i>pseudo</i>-Michaelis complexes, respectively. At the peripheral binding site, the substrate is bound in the zwitterionic form. By analyzing the observed protonation states, Glu53, but not His residues, is proposed as the general base catalyst, orchestrating the retro-aldol transformation of L-serine into glycine.</p> </div> </div> </section> <noscript> </noscript> <section aria-labelledby="inline-recommendations" data-title="Inline Recommendations" class="c-article-recommendations" data-track-component="inline-recommendations"> <h3 class="c-article-recommendations-title" id="inline-recommendations">Similar content being viewed by others</h3> <div class="c-article-recommendations-list"> <div class="c-article-recommendations-list__item"> <article class="c-article-recommendations-card" itemscope itemtype="http://schema.org/ScholarlyArticle"> <div class="c-article-recommendations-card__img"> <img src="https://media.springernature.com/w215h120/springer-static/image/art%3A10.1038%2Fs41467-020-20032-3/MediaObjects/41467_2020_20032_Fig1_HTML.png" loading="lazy" alt=""> </div> <div class="c-article-recommendations-card__main"> <h3 class="c-article-recommendations-card__heading" itemprop="name headline"><a class="c-article-recommendations-card__link" itemprop="url" href="https://www-nature-com.translate.goog/articles/s41467-020-20032-3?fromPaywallRec=false&_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track="select_recommendations_1" data-track-context="inline recommendations" data-track-action="click recommendations inline - 1" data-track-label="10.1038/s41467-020-20032-3">Hydrogen-deuterium exchange mass spectrometry captures distinct dynamics upon substrate and inhibitor binding to a transporter </a></h3> <div class="c-article-meta-recommendations" data-test="recommendation-info"><span class="c-article-meta-recommendations__item-type">Article</span> <span class="c-article-meta-recommendations__access-type">Open access</span> <span class="c-article-meta-recommendations__date">02 December 2020</span> </div> </div> </article> </div> <div class="c-article-recommendations-list__item"> <article class="c-article-recommendations-card" itemscope itemtype="http://schema.org/ScholarlyArticle"> <div class="c-article-recommendations-card__img"> <img src="https://media.springernature.com/w215h120/springer-static/image/art%3A10.1038%2Fs41586-021-04355-9/MediaObjects/41586_2021_4355_Fig1_HTML.png" loading="lazy" alt=""> </div> <div class="c-article-recommendations-card__main"> <h3 class="c-article-recommendations-card__heading" itemprop="name headline"><a class="c-article-recommendations-card__link" itemprop="url" href="https://www-nature-com.translate.goog/articles/s41586-021-04355-9?fromPaywallRec=false&_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track="select_recommendations_2" data-track-context="inline recommendations" data-track-action="click recommendations inline - 2" data-track-label="10.1038/s41586-021-04355-9">Crystallographic snapshots of a B<sub>12</sub>-dependent radical SAM methyltransferase </a></h3> <div class="c-article-meta-recommendations" data-test="recommendation-info"><span class="c-article-meta-recommendations__item-type">Article</span> <span class="c-article-meta-recommendations__access-type">Open access</span> <span class="c-article-meta-recommendations__date">02 February 2022</span> </div> </div> </article> </div> <div class="c-article-recommendations-list__item"> <article class="c-article-recommendations-card" itemscope itemtype="http://schema.org/ScholarlyArticle"> <div class="c-article-recommendations-card__img"> <img src="https://media.springernature.com/w215h120/springer-static/image/art%3A10.1038%2Fs41598-020-61217-6/MediaObjects/41598_2020_61217_Fig1_HTML.png" loading="lazy" alt=""> </div> <div class="c-article-recommendations-card__main"> <h3 class="c-article-recommendations-card__heading" itemprop="name headline"><a class="c-article-recommendations-card__link" itemprop="url" href="https://www-nature-com.translate.goog/articles/s41598-020-61217-6?fromPaywallRec=false&_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track="select_recommendations_3" data-track-context="inline recommendations" data-track-action="click recommendations inline - 3" data-track-label="10.1038/s41598-020-61217-6">X-ray Crystallography and Electron Paramagnetic Resonance Spectroscopy Reveal Active Site Rearrangement of Cold-Adapted Inorganic Pyrophosphatase </a></h3> <div class="c-article-meta-recommendations" data-test="recommendation-info"><span class="c-article-meta-recommendations__item-type">Article</span> <span class="c-article-meta-recommendations__access-type">Open access</span> <span class="c-article-meta-recommendations__date">09 March 2020</span> </div> </div> </article> </div> </div> </section> <script> window.dataLayer = window.dataLayer || []; window.dataLayer.push({ recommendations: { recommender: 'semantic', model: 'specter', policy_id: 'NA', timestamp: 1732704432, embedded_user: 'null' } }); </script> <div class="main-content"> <section data-title="Introduction"> <div class="c-article-section" id="Sec1-section"> <h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Sec1">Introduction</h2> <div class="c-article-section__content" id="Sec1-content"> <p>Found in all living organisms, pyridoxal 5’-phosphate (PLP)-dependent enzymes utilize a phosphorylated, biologically active form of vitamin B<sub>6</sub> (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig1">1a</a>) to catalyze a myriad of chemical reactions including transamination, β- and γ-elimination, α-decarboxylation, retro-aldol cleavages, and glycogen phosphorylation<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1" title="Eliot, A. C. & Kirsch, J. F. Pyridoxal phosphate enzymes: mechanistic, structural, and evolutionary considerations. Annu Rev. Biochem 73, 383–415 (2004)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR1" id="ref-link-section-d2316419e611">1</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 2" title="Liang, J., Han, Q., Tan, Y., Ding, H. & Li, J. Current advances on structure-function relationships of pyridoxal 5’-phosphate-dependent enzymes. Front Mol. Biosci. 6, 4 (2019)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR2" id="ref-link-section-d2316419e614">2</a></sup>. PLP-dependent enzymes have been organized into seven fold types based on their evolutionary lineages, however, within these groupings, there are multiple catalytic activities<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Grishin, N. V., Phillips, M. A. & Goldsmith, E. J. Modeling of the Spatial Structure of Eukaryotic Ornithine Decarboxylases. Protein Sci. 4, 1291–1304 (1995)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR3" id="ref-link-section-d2316419e618">3</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Jansonius, J. N. Structure, evolution and action of vitamin B6-dependent enzymes. Curr. Opin. Struct. Biol. 8, 759–769 (1998)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR4" id="ref-link-section-d2316419e618_1">4</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 5" title="Percudani, R. & Peracchi, A. A genomic overview of pyridoxal-phosphate-dependent enzymes. EMBO Rep. 4, 850–854 (2003)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR5" id="ref-link-section-d2316419e621">5</a></sup>. The largest group of PLP-dependent enzymes is the aminotransferase superfamily (Fold I). Hence, PLP-dependent enzymes, owing to their versatility, are physiologically significant for the metabolism, interconversion, and synthesis of various amino acids. Unsurprisingly, many PLP-dependent enzymes are recognized as drug targets for the development of small-molecule therapeutics and have also been exploited for the synthesis of building blocks for pharmaceutical applications<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 6" title="Amadasi, A. et al. Pyridoxal 5’-phosphate enzymes as targets for therapeutic agents. Curr. Med Chem. 14, 1291–1324 (2007)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR6" id="ref-link-section-d2316419e625">6</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 7" title="Steffen-Munsberg, F. et al. Bioinformatic analysis of a PLP-dependent enzyme superfamily suitable for biocatalytic applications. Biotechnol. Adv. 33, 566–604 (2015)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR7" id="ref-link-section-d2316419e628">7</a></sup>.</p> <div class="c-article-section__figure js-c-reading-companion-figures-item" data-test="figure" data-container-section="figure" id="figure-1" data-title="SHMT catalyzed reaction, enzyme 3D structure, and sequence alignment of TthSHMT and hSHMT2."> <figure> <figcaption> <b id="Fig1" class="c-article-section__figure-caption" data-test="figure-caption-text">Fig. 1: SHMT catalyzed reaction, enzyme 3D structure, and sequence alignment of <i>Tth</i>SHMT and hSHMT2.</b> </figcaption> <div class="c-article-section__figure-content"> <div class="c-article-section__figure-item"> <a class="c-article-section__figure-link" data-test="img-link" data-track="click" data-track-label="image" data-track-action="view figure" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9/figures/1?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" rel="nofollow"> <picture> <source type="image/webp" srcset="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://media.springernature.com/lw685/springer-static/image/art%253A10.1038%252Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig1_HTML.png?as%3Dwebp"> <img aria-describedby="Fig1" src="//media.springernature.com/lw685/springer-static/image/art%3A10.1038%2Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig1_HTML.png" alt="figure 1" loading="lazy" width="685" height="816"> </picture></a> </div> <div class="c-article-section__figure-description" data-test="bottom-caption" id="figure-1-desc"> <p><b>a</b> Chemical structures of vitamin B<sub>6</sub>, PLP, and the internal aldimine. Atom labels are given on the internal aldimine structure. <b>b</b> THF-dependent conversion of L-Ser to Gly catalyzed by SHMT. <b>c</b> Overview of the overall fold of SHMT proteins from human mitochondria (hSHMT2) and <i>Thermus thermophilus</i> (<i>Tth</i>SHMT). Individual protomers are depicted in different color schemes and PLP cofactors are shown with CPK representation. hSHMT2 exists as a homotetramer made up of obligate dimers, whereas <i>Tth</i>SHMT is a homodimer. <b>d</b> <i>Tth</i>SHMT and hSHMT2 sequence alignment. Active sites are conserved between the two enzymes, highlighted in red. The sequence identity is 41%.</p> </div> </div> <div class="u-text-right u-hide-print"> <a class="c-article__pill-button" data-test="article-link" data-track="click" data-track-label="button" data-track-action="view figure" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9/figures/1?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track-dest="link:Figure1 Full size image" aria-label="Full size image figure 1" rel="nofollow"><span>Full size image</span> <svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"> <use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-chevron-right-small" /> </svg></a> </div> </figure> </div> <p>PLP-dependent catalysis is enabled by the stereoelectronic control of the labile covalent linkage, called the Schiff base, formed between the PLP cofactor and the side-chain amino group of a catalytic lysine (Lys) residue to create the internal aldimine functional state (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig1">1a</a>), and by the ability of the enzyme active sites to stabilize charged intermediates through the electron withdrawing properties of the pyridine ring<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Dunathan, H. C. Conformation and reaction specificity in pyridoxal phosphate enzymes. Proc. Natl Acad. Sci. USA 55, 712 (1966)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR8" id="ref-link-section-d2316419e689">8</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Richard, J. P., Amyes, T. L., Crugeiras, J. & Rios, A. Pyridoxal 5 ’-phosphate: electrophilic catalyst extraordinaire. Curr. Opin. Chem. Biol. 13, 475–483 (2009)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR9" id="ref-link-section-d2316419e689_1">9</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 10" title="Toney, M. D. Controlling reaction specificity in pyridoxal phosphate enzymes. Biochim Biophys. Acta 1814, 1407–1418 (2011)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR10" id="ref-link-section-d2316419e692">10</a></sup>. These principles, however, do not fully explain the catalytic diversity of the PLP-dependent enzymes, but rather it appears that the manifold of PLP-dependent activities is governed by the surrounding protein environment and the electronic modulation of the cofactor through selective protonation. Consequently, PLP-dependent catalysis cannot be completely understood without knowing the protonation states of the cofactor and the surrounding residues that are dictated by the locations of hydrogen (H) atoms, which determine the electrostatic environment within the active site.</p> <p>Serine hydroxymethyltransferase (SHMT), a ubiquitous PLP-dependent enzyme in the aminotransferase superfamily, catalyzes the reversible conversion of L-serine (L-Ser) to glycine (Gly), transferring a one-carbon unit to tetrahydrofolate (THF) to yield 5,10-methylenetetrahydrofolate (5,10-MTHF) (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig1">1b</a>)<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 5" title="Percudani, R. & Peracchi, A. A genomic overview of pyridoxal-phosphate-dependent enzymes. EMBO Rep. 4, 850–854 (2003)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR5" id="ref-link-section-d2316419e702">5</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 11" title="Schirch, L. Serine Hydroxymethyltransferase. Adv. Enzymol. Ramb 53, 83–112 (1982)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR11" id="ref-link-section-d2316419e705">11</a></sup>. SHMT exhibits some catalytic promiscuity, similar to many PLP-dependent enzymes, and can catalyze THF-independent reactions such as the reversible cleavage of β-hydroxy amino acids<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 12" title="Ulevitch, R. J. & Kallen, R. G. Studies of reactions of lamb liver serine hydroxymethylase with l-phenylalanine - kinetic isotope effects upon quinonoid intermediate formation. Biochemistry 16, 5350–5354 (1977)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR12" id="ref-link-section-d2316419e709">12</a></sup>, decarboxylation of aminomalonates<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 13" title="Thomas, N. R., Schirch, V. & Gani, D. Synthesis of (2r)-[1-C-13]-2-Amino-2-Methylmalonic and (2s)-[1-C-13]-2-Amino-2-Methylmalonic Acid, Probes for the Serine Hydroxymethyltransferase Reaction - Stereospecific Decarboxylation of the 2-Pro-R Carboxy Group with the Retention of Configuration. J. Chem. Soc. Chem. Comm. 400–402, https://doi.org/10.1039/c39900000400 (1990)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR13" id="ref-link-section-d2316419e713">13</a></sup>, and the racemization and transamination of D- and L-alanine<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 14" title="Shostak, K. & Schirch, V. Serine hydroxymethyltransferase: mechanism of the racemization and transamination of D- and L-alanine. Biochemistry 27, 8007–8014 (1988)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR14" id="ref-link-section-d2316419e717">14</a></sup>. As an enzyme in one-carbon metabolism, SHMT is essential to the synthesis of thymine nucleotides, purines, methionine, and other essential biomolecules<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 15" title="Herbig, K. et al. Cytoplasmic serine hydroxymethyltransferase mediates competition between folate-dependent deoxyribonucleotide and S-adenosylmethionine biosyntheses. J. Biol. Chem. 277, 38381–38389 (2002)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR15" id="ref-link-section-d2316419e722">15</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 16" title="Xie, M. & Pei, D. S. Serine hydroxymethyltransferase 2: a novel target for human cancer therapy. Invest N. Drug 39, 1671–1681 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR16" id="ref-link-section-d2316419e725">16</a></sup>. SHMT is found as a homodimer in prokaryotes, such as <i>Thermus thermophilus</i> (<i>Tth</i>), and a homotetramer in eukaryotes, such as humans (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig1">1c and d</a>)<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 17" title="Florio, R., di Salvo, M. L., Vivoli, M. & Contestabile, R. Serine hydroxymethyltransferase: a model enzyme for mechanistic, structural, and evolutionary studies. Biochim Biophys. Acta 1814, 1489–1496 (2011)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR17" id="ref-link-section-d2316419e738">17</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 18" title="Giardina, G. et al. How pyridoxal 5’-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state. FEBS J. 282, 1225–1241 (2015)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR18" id="ref-link-section-d2316419e741">18</a></sup>. One-carbon metabolism is compartmentalized in mammals and hence requires two SHMT isoforms, SHMT1 and SHMT2, located in the cytosol and mitochondria, respectively<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 18" title="Giardina, G. et al. How pyridoxal 5’-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state. FEBS J. 282, 1225–1241 (2015)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR18" id="ref-link-section-d2316419e745">18</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 19" title="Tramonti, A. et al. Human cytosolic and mitochondrial serine hydroxymethyltransferase isoforms in comparison: full kinetic characterization and substrate inhibition properties. Biochemistry 57, 6984–6996 (2018)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR19" id="ref-link-section-d2316419e748">19</a></sup>. SHMT1 and SHMT2 catalyze equivalent biochemical reactions and have a sequence identity of ~66%<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 20" title="Garrow, T. A. et al. Cloning of human cdnas encoding mitochondrial and cytosolic serine hydroxymethyltransferases and chromosomal localization. J. Biol. Chem. 268, 11910–11916 (1993)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR20" id="ref-link-section-d2316419e753">20</a></sup>. Interestingly, in many cancer cell lines, these reactions proceed in opposite directions in SHMT1 and SHMT2, with SHMT2 providing the majority of one-carbon units in mitochondria from serine synthesized by SHMT1 in the cytosol<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 21" title="Ducker, G. S. & Rabinowitz, J. D. One-carbon metabolism in health and disease. Cell Metab. 25, 27–42 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR21" id="ref-link-section-d2316419e757">21</a></sup>.</p> <p>Human SHMT2 (hSHMT2, Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig1">1c</a>) has been found to be highly overexpressed in many types of cancers as a result of metabolic reprogramming of the one-carbon metabolism<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Lee, G. Y. et al. Comparative oncogenomics identifies PSMB4 and SHMT2 as potential cancer driver genes. Cancer Res 74, 3114–3126 (2014)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR22" id="ref-link-section-d2316419e767">22</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Giardina, G. et al. The catalytic activity of serine hydroxymethyltransferase is essential for de novo nuclear dTMP synthesis in lung cancer cells. FEBS J. 285, 3238–3253 (2018)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR23" id="ref-link-section-d2316419e767_1">23</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Li, A. M. et al. Metabolic profiling reveals a dependency of human metastatic breast cancer on mitochondrial serine and one-carbon unit metabolism. Mol. Cancer Res. 18, 599–611 (2020)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR24" id="ref-link-section-d2316419e767_2">24</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Wu, Z. Z. et al. Increased expression of SHMT2 is associated with poor prognosis and advanced pathological grade in oral squamous cell carcinoma. Front Oncol. 10, 588530 (2020)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR25" id="ref-link-section-d2316419e767_3">25</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Yang, C. C. et al. Folate-mediated one-carbon metabolism: a targeting strategy in cancer therapy. Drug Discov. Today 26, 817–825 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR26" id="ref-link-section-d2316419e767_4">26</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 27" title="Cui, X. M. et al. SHMT2 drives the progression of colorectal cancer by regulating UHRF1 expression. Can. J. Gastroenterol. 2022, 3758697 (2022)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR27" id="ref-link-section-d2316419e770">27</a></sup>. Additionally, high levels of hSHMT2 expression have been linked to poor cancer prognoses and to resistance to 5-fluorouracil, one of the most commonly used drugs to treat cancer<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Zeng, Y. et al. Roles of mitochondrial serine hydroxymethyltransferase 2 (SHMT2) in human carcinogenesis. J. Cancer 12, 5888–5894 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR28" id="ref-link-section-d2316419e774">28</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Du, J. et al. Serine hydroxymethyltransferase 2 predicts unfavorable outcomes in multiple cancer: a systematic review and meta-analysis. Transl. Cancer Res 11, 444–455 (2022)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR29" id="ref-link-section-d2316419e774_1">29</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Pranzini, E. et al. SHMT2-mediated mitochondrial serine metabolism drives 5-FU resistance by fueling nucleotide biosynthesis. Cell Rep. 40, 111233 (2022)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR30" id="ref-link-section-d2316419e774_2">30</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 31" title="Clark, R. A., Qiao, J., Jacobson, J. C. & Chung, D. H. Induction of serine hydroxymethyltransferase 2 promotes tumorigenesis and metastasis in neuroblastoma. Oncotarget 13, 32–45 (2022)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR31" id="ref-link-section-d2316419e777">31</a></sup>. The significance of hSHMT2 in the proliferation and drug resistance of cancer cells has made this enzyme an attractive drug target for antimetabolite chemotherapies<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 16" title="Xie, M. & Pei, D. S. Serine hydroxymethyltransferase 2: a novel target for human cancer therapy. Invest N. Drug 39, 1671–1681 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR16" id="ref-link-section-d2316419e781">16</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 32" title="Cuthbertson, C. R., Arabzada, Z., Bankhead, A., Kyani, A. & Neamati, N. A review of small-molecule inhibitors of one-carbon enzymes: SHMT2 and MTHFD2 in the Spotlight. ACS Pharm. Transl. 4, 624–646 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR32" id="ref-link-section-d2316419e784">32</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 33" title="Stine, Z. E., Schug, Z. T., Salvino, J. M. & Dang, C. V. Targeting cancer metabolism in the era of precision oncology. Nat. Rev. Drug Discov. 21, 141–162 (2022)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR33" id="ref-link-section-d2316419e787">33</a></sup>, and several promising hSHMT2 inhibitors have been discovered<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Han, Y. et al. Identification of three new compounds that directly target human serine hydroxymethyltransferase 2. Chem. Biol. Drug Des. 97, 221–230 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR34" id="ref-link-section-d2316419e791">34</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Garcia-Canaveras, J. C. et al. SHMT inhibition is effective and synergizes with methotrexate in T-cell acute lymphoblastic leukemia. Leukemia 35, 377–388 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR35" id="ref-link-section-d2316419e791_1">35</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Pikman, Y. et al. Targeting serine hydroxymethyltransferases 1 and 2 for T-cell acute lymphoblastic leukemia therapy. Leukemia 36, 348–360 (2022)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR36" id="ref-link-section-d2316419e791_2">36</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 37" title="Ducker, G. S. et al. Human SHMT inhibitors reveal defective glycine import as a targetable metabolic vulnerability of diffuse large B-cell lymphoma. Proc. Natl Acad. Sci. USA 114, 11404–11409 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR37" id="ref-link-section-d2316419e794">37</a></sup>. To advance drug design<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 38" title="McConnell, D. B. Biotin’s lessons in drug design. J. Med Chem. 64, 16319–16327 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR38" id="ref-link-section-d2316419e799">38</a></sup> of hSHMT2-specific inhibitors, it is critical to understand the SHMT catalysis at the atomic level. However, there is a gap in our knowledge of the SHMT-catalyzed reaction mechanism, which is based on acid-base chemistry, because the locations and movement of H atoms along the reaction pathway are not known.</p> <p>Hydrogen (H) atoms comprise ~50% of all atoms in proteins and contribute to most noncovalent interactions, such as H-bonding, van der Waal’s forces, and electrostatics. Thus, H atoms are key players in enzyme substrate and ligand binding, protein-protein interactions, and proton transfer reactions<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 39" title="Engler, N., Ostermann, A., Niimura, N. & Parak, F. G. Hydrogen atoms in proteins: positions and dynamics. Proc. Natl Acad. Sci. USA 100, 10243–10248 (2003)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR39" id="ref-link-section-d2316419e807">39</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 40" title="Bax, B., Chung, C. & Edge, C. Getting the chemistry right: protonation, tautomers and the importance of H atoms in biological chemistry. Acta Crystallogr. Sect. D. 73, 131–140 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR40" id="ref-link-section-d2316419e810">40</a></sup>. Moreover, the presence or absence of an H atom in a chemical group, such as imidazole of histidine (His) or carboxylate of aspartate/glutamate (Asp/Glu), determines the protonation state and thereby the electrical charge of that amino acid residue. Whereas X-ray diffraction continues to be the gold standard in protein structure determination, the resultant structures provide little to no information on the positions of functional H atoms even at ultrahigh resolutions<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 41" title="Gardberg, A. S. et al. Unambiguous determination of H-atom positions: comparing results from neutron and high-resolution X-ray crystallography. Acta Crystallogr. Sect. D.-Struct. Biol. 66, 558–567 (2010)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR41" id="ref-link-section-d2316419e814">41</a></sup>. This is a consequence of the X-ray scattering magnitude of H being significantly smaller than that for the other atoms in biomacromolecular structures. Because H and its heavier isotope deuterium (D) atoms have comparable neutron scattering lengths to heavier atoms (C, N, O) within the protein, neutron diffraction can resolve the positions of H/D at moderate resolutions<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Niimura, N. & Podjarny, A. Neutron Protein Crystallography: Hydrogen, Protons, and Hydration in Bio-macromolecules, 232 (Oxford University Press, Oxford, UK, 2011)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR42" id="ref-link-section-d2316419e818">42</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Gerlits, O. et al. Long-range electrostatics-induced two-proton transfer captured by neutron crystallography in an enzyme catalytic site. Angew. Chem. Int Ed. Engl. 55, 4924–4927 (2016)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR43" id="ref-link-section-d2316419e818_1">43</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Dajnowicz, S. et al. Direct visualization of critical hydrogen atoms in a pyridoxal 5’-phosphate enzyme. Nat. Commun. 8, 955 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR44" id="ref-link-section-d2316419e818_2">44</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 45" title="Drago, V. N. et al. An N···H···N low-barrier hydrogen bond preorganizes the catalytic site of aspartate aminotransferase to facilitate the second half-reaction. Chem. Sci. 13, 10057–10065 (2022)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR45" id="ref-link-section-d2316419e821">45</a></sup>. The ability to assign protonation states based on the location of H/D atoms by neutron diffraction is critical to understanding the mechanism of catalysis, molecular recognition, and in designing specific inhibitors through structure-based drug design<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Fisher, S. Z., Aggarwal, M., Kovalevsky, A. Y., Silverman, D. N. & McKenna, R. Neutron diffraction of acetazolamide-bound human carbonic anhydrase II reveals atomic details of drug binding. J. Am. Chem. Soc. 134, 14726–14729 (2012)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR46" id="ref-link-section-d2316419e825">46</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Weber, I. T. et al. Joint X-ray/neutron crystallographic study of HIV-1 protease with clinical inhibitor amprenavir: insights for drug design. J. Med. Chem. 56, 5631–5635 (2013)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR47" id="ref-link-section-d2316419e825_1">47</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Manzoni, F. et al. Elucidation of hydrogen bonding patterns in ligand-free, lactose- and glycerol-bound galectin-3c by neutron crystallography to guide drug design. J. Med. Chem. 61, 4412–4420 (2018)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR48" id="ref-link-section-d2316419e825_2">48</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Kneller, D. W. et al. Structural, electronic, and electrostatic determinants for inhibitor binding to subsites S1 and S2 in SARS-CoV-2 main protease. J. Med Chem. 64, 17366–17383 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR49" id="ref-link-section-d2316419e825_3">49</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 50" title="Kneller, D. et al. Covalent narlaprevir- and boceprevir-derived hybrid inhibitors of SARS-CoV-2 main protease: room-temperature X-ray and neutron crystallography, binding thermodynamics, and antiviral activity. Res. Sq. https://doi.org/10.21203/rs.3.rs-1318037/v1 (2022)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR50" id="ref-link-section-d2316419e828">50</a></sup>. As a result, a neutron structure can help resolve a biochemical issue for a specific protein<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 51" title="Gerlits, O. et al. Zooming in on protons: neutron structure of protein kinase a trapped in a product complex. Sci. Adv. 5, eaav0482 (2019)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR51" id="ref-link-section-d2316419e832">51</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 52" title="Kumar, M. et al. Visualizing tetrahedral oxyanion bound in HIV-1 protease using neutrons: implications for the catalytic mechanism and drug design. ACS Omega 5, 11605–11617 (2020)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR52" id="ref-link-section-d2316419e835">52</a></sup> and provide an accurate model for drug design<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 49" title="Kneller, D. W. et al. Structural, electronic, and electrostatic determinants for inhibitor binding to subsites S1 and S2 in SARS-CoV-2 main protease. J. Med Chem. 64, 17366–17383 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR49" id="ref-link-section-d2316419e840">49</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 50" title="Kneller, D. et al. Covalent narlaprevir- and boceprevir-derived hybrid inhibitors of SARS-CoV-2 main protease: room-temperature X-ray and neutron crystallography, binding thermodynamics, and antiviral activity. Res. Sq. https://doi.org/10.21203/rs.3.rs-1318037/v1 (2022)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR50" id="ref-link-section-d2316419e843">50</a></sup>.</p> <p>The first step in the SHMT-catalyzed conversion of L-Ser to Gly is the formation of the external aldimine through a transaldimination reaction with the L-Ser substrate, a common feature for PLP-dependent enzymes. The amino group of L-Ser displaces the catalytic Lys, initially covalently linked to PLP within the internal aldimine state, to generate an external aldimine state followed by THF binding that ultimately leads to the THF-dependent conversion of L-Ser to Gly and 5,10-MTHF production. However, there is no accepted catalytic mechanism for this conversion, but the available literature contains two predominant hypotheses (Figure <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S1</a>)<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Renwick, S. B., Snell, K. & Baumann, U. The crystal structure of human cytosolic serine hydroxymethyltransferase: a target for cancer chemotherapy. Structure 6, 1105–1116 (1998)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR53" id="ref-link-section-d2316419e853">53</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Trivedi, V. et al. Crystal structure of binary and ternary complexes of serine hydroxymethyltransferase from Bacillus stearothermophilus - Insights into the catalytic mechanism. J. Biol. Chem. 277, 17161–17169 (2002)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR54" id="ref-link-section-d2316419e853_1">54</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Szebenyi, D. M. E., Musayev, F. N., di Salvo, M. L., Safo, M. K. & Schirch, V. Serine hydroxymethyltransferase: role of Glu75 and evidence that serine is cleaved by a retroaldol mechanism. Biochemistry 43, 6865–6876 (2004)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR55" id="ref-link-section-d2316419e853_2">55</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 56" title="Schirch, V. & Szebenyi, D. M. Serine hydroxymethyltransferase revisited. Curr. Opin. Chem. Biol. 9, 482–487 (2005)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR56" id="ref-link-section-d2316419e856">56</a></sup>. In a proposed two-step mechanism, after the external aldimine is formed, the β-hydroxyl of L-Ser is deprotonated by a general base, presumably Glu53 in <i>Tth</i>SHMT (Glu98 in hSHMT2, Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig1">1d</a>), in a retro-aldol reaction to promote the release of formaldehyde. The transient formaldehyde intermediate then undergoes a nucleophilic attack by the endocyclic N5 atom of THF, likely without dissociating from the active site. A histidine residue (His122 in <i>Tth</i>SHMT, His171 in hSHMT2) has also been suggested as a possible general base in this mechanism<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 53" title="Renwick, S. B., Snell, K. & Baumann, U. The crystal structure of human cytosolic serine hydroxymethyltransferase: a target for cancer chemotherapy. Structure 6, 1105–1116 (1998)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR53" id="ref-link-section-d2316419e870">53</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 57" title="Jagath, J. R. et al. Importance of the amino terminus in maintenance of oligomeric structure of sheep liver cytosolic serine hydroxymethyltransferase. Eur. J. Biochem 247, 372–379 (1997)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR57" id="ref-link-section-d2316419e873">57</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 58" title="Rao, N. A., Ambili, M., Jala, V. R., Subramanya, H. S. & Savithri, H. S. Structure-function relationship in serine hydroxymethyltransferase. Biochim. Biophys. Acta-Proteins Proteom. 1647, 24–29 (2003)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR58" id="ref-link-section-d2316419e876">58</a></sup>. In the competing one-step mechanism, Cβ of L-Ser within the external aldimine undergoes a direct nucleophilic attack by THF N5, facilitating α-elimination. In this reaction mechanism, protonation of Glu53 is obligatory as it acts as a general acid to protonate the hydroxyl to dehydrate Cβ<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 55" title="Szebenyi, D. M. E., Musayev, F. N., di Salvo, M. L., Safo, M. K. & Schirch, V. Serine hydroxymethyltransferase: role of Glu75 and evidence that serine is cleaved by a retroaldol mechanism. Biochemistry 43, 6865–6876 (2004)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR55" id="ref-link-section-d2316419e880">55</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 56" title="Schirch, V. & Szebenyi, D. M. Serine hydroxymethyltransferase revisited. Curr. Opin. Chem. Biol. 9, 482–487 (2005)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR56" id="ref-link-section-d2316419e883">56</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 59" title="Matthews, R. G. & Drummond, J. T. Providing one-carbon units for biological methylations - Mechanistic studies on serine hydroxymethyltransferase, methylenetetrahydrofolate reductase, and methyltetrahydrofolate-homocysteine methyltransferase. Chem. Rev. 90, 1275–1290 (1990)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR59" id="ref-link-section-d2316419e886">59</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 60" title="Fernandes, H. S., Ramos, M. J. & Cerqueira, N. M. F. S. A. Catalytic mechanism of the serine hydroxymethyltransferase: a computational ONIOM QM/MM study. ACS Catal. 8, 10096–10110 (2018)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR60" id="ref-link-section-d2316419e889">60</a></sup>. Interestingly, within the one-step mechanism, the reaction has been proposed to proceed either by a nucleophilic displacement route through an intermediate having a covalent bond between L-Ser Cβ and THF N5 that links the external aldimine to THF, or by a concerted mechanism in which the Cβ-N5 bond formation and Cβ-Cα bond breakage occur simultaneously in the transition state to generate an intermediate product, 5-hydroxymethyl-THF. Furthermore, additional protonation/deprotonation events must occur in both proposed mechanisms that involve the THF molecule and other active site residues for the reaction to reach the final products, Gly and 5,10-MTHF. It is also known that SHMT can convert some β-hydroxyamino acids, such as L-threonine and β-phenylserine, in the THF-independent fashion to afford corresponding aldehydes<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 17" title="Florio, R., di Salvo, M. L., Vivoli, M. & Contestabile, R. Serine hydroxymethyltransferase: a model enzyme for mechanistic, structural, and evolutionary studies. Biochim Biophys. Acta 1814, 1489–1496 (2011)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR17" id="ref-link-section-d2316419e893">17</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 55" title="Szebenyi, D. M. E., Musayev, F. N., di Salvo, M. L., Safo, M. K. & Schirch, V. Serine hydroxymethyltransferase: role of Glu75 and evidence that serine is cleaved by a retroaldol mechanism. Biochemistry 43, 6865–6876 (2004)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR55" id="ref-link-section-d2316419e896">55</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 61" title="Nonaka, H. et al. Design strategy for serine hydroxymethyltransferase probes based on retro-aldol-type reaction. Nat. Commun. 10, 876 (2019)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR61" id="ref-link-section-d2316419e899">61</a></sup>, which would presumably require the same general base as in the THF-dependent reaction to deprotonate the hydroxyl of the β-substituted amino acid within the respective external aldimine. Taken together, the described THF-dependent SHMT catalytic mechanisms that have been proposed each require as many as six general acid-base groups, although some of them would likely be involved multiple times throughout the reaction pathway, possibly switching their roles, and thereby reducing the number to two or three<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 54" title="Trivedi, V. et al. Crystal structure of binary and ternary complexes of serine hydroxymethyltransferase from Bacillus stearothermophilus - Insights into the catalytic mechanism. J. Biol. Chem. 277, 17161–17169 (2002)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR54" id="ref-link-section-d2316419e903">54</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 55" title="Szebenyi, D. M. E., Musayev, F. N., di Salvo, M. L., Safo, M. K. & Schirch, V. Serine hydroxymethyltransferase: role of Glu75 and evidence that serine is cleaved by a retroaldol mechanism. Biochemistry 43, 6865–6876 (2004)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR55" id="ref-link-section-d2316419e906">55</a></sup>. Discriminating between these reaction mechanisms and pinpointing the general acids and bases involved will require knowledge of the protonation states of the enzyme active site residues, PLP, and THF at different reaction stages – details that can be divulged through neutron crystallography.</p> <p>PLP-bound hSHMT2 forms hexagonal, rod-shaped crystals, space group P6<sub>5</sub>22, with long cell edges (>150 Å) that diffract X-rays to resolutions of 2.3–2.5 Å using synchrotron radiation at cryogenic temperatures<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 18" title="Giardina, G. et al. How pyridoxal 5’-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state. FEBS J. 282, 1225–1241 (2015)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR18" id="ref-link-section-d2316419e915">18</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 37" title="Ducker, G. S. et al. Human SHMT inhibitors reveal defective glycine import as a targetable metabolic vulnerability of diffuse large B-cell lymphoma. Proc. Natl Acad. Sci. USA 114, 11404–11409 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR37" id="ref-link-section-d2316419e918">37</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 62" title="Scaletti, E., Jemth, A. S., Helleday, T. & Stenmark, P. Structural basis of inhibition of the human serine hydroxymethyltransferase SHMT2 by antifolate drugs. FEBS Lett. 593, 1863–1873 (2019)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR62" id="ref-link-section-d2316419e921">62</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 63" title="Ota, T. et al. Structural basis for selective inhibition of human serine hydroxymethyltransferase by secondary bile acid conjugate. iScience 24, 102036 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR63" id="ref-link-section-d2316419e924">63</a></sup>. Such hSHMT2 crystals are not amenable to neutron crystallography on the currently available neutron crystallographic beamlines where neutron beam fluxes are significantly weaker than the X-ray beam fluxes at modern synchrotron facilities<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 64" title="Blakeley, M. P. & Podjarny, A. D. Neutron macromolecular crystallography. Emerg. Top. Life Sci. 2, 39–55 (2018)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR64" id="ref-link-section-d2316419e928">64</a></sup>. Like many metabolic enzymes, SHMT is evolutionarily highly conserved, especially in the active site, enabling us to utilize SHMT from <i>Thermus thermophilus</i> (<i>Tth</i>SHMT, Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig1">1c</a> and S<a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">2</a>) as a model of the mitochondrial human enzyme. <i>Tth</i>SHMT and hSHMT2, both fold type I PLP-dependent enzymes, have completely conserved active sites (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig1">1d</a> and S<a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">3</a>), but the crystallographic unit cell volume of <i>Tth</i>SHMT is considerably smaller than that of its human counterpart. <i>Tth</i>SHMT crystals are well-diffracting, permitting us to use them for room-temperature X-ray and neutron diffraction experiments. Here, we present a 2.3 Å joint X-ray/neutron (XN) structure of the homodimeric <i>Tth</i>SHMT in the open conformation. The XN structure depicts equivalent active sites in the two protomers with the PLP cofactor covalently bound to the catalytic Lys226 in the internal aldimine state and a sulfate ion filling the substrate binding site in each protomer. For direct comparison with the joint XN structure, we also determined a 2.5 Å room-temperature X-ray structure of hSHMT2 in the internal aldimine state. To track an amino acid substrate within the SHMT active site cavity, we obtained a second joint XN structure by soaking the same <i>Tth</i>SHMT crystal with deuterated L-Ser (L-Ser-d<sub>7</sub>). This structure revealed L-Ser-d<sub>7</sub> bound in a solvent-exposed peripheral substrate binding site at the entrance to the active site cavity in an apparent <i>pre</i>-Michaelis complex, with the sulfate anion continuing to block the L-Ser-d<sub>7</sub> entry deeper into the active site cavity. We further tracked the substrate through the active site cavity by obtaining a room-temperature X-ray structure of a <i>pseudo</i>-Michaelis complex by soaking a <i>Tth</i>SHMT crystal with D-Ser, a non-reactive enantiomer of L-Ser, which displaced the sulfate anion in protomer A occupying the cationic substrate binding site. Positions of H atoms were revealed by the nuclear density maps in the XN structures, thereby allowing us to accurately assign the protonation states and electrical charges for all amino acid residues, L-Ser substrate, and the PLP. By directly observing H atom locations and tracking the substrate positions, our study provides a unique atomic-level understanding of the SHMT active site that sheds new light on the enzyme’s catalytic mechanism by eliminating speculation on the roles of many active site residues. We believe this knowledge can be also employed to inform the design of anticancer drugs targeting hSHMT2.</p> </div> </div> </section> <section data-title="Results"> <div class="c-article-section" id="Sec2-section"> <h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Sec2">Results</h2> <div class="c-article-section__content" id="Sec2-content"> <h3 class="c-article__sub-heading" id="Sec3">Accurate map of protonation states in substrate-free <i>Tth</i>SHMT</h3> <p>SHMTs from prokaryotic sources function as biological homodimers, whereas eukaryotic SHMTs exist as homotetramers composed of a dimer of dimers<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 17" title="Florio, R., di Salvo, M. L., Vivoli, M. & Contestabile, R. Serine hydroxymethyltransferase: a model enzyme for mechanistic, structural, and evolutionary studies. Biochim Biophys. Acta 1814, 1489–1496 (2011)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR17" id="ref-link-section-d2316419e999">17</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 18" title="Giardina, G. et al. How pyridoxal 5’-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state. FEBS J. 282, 1225–1241 (2015)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR18" id="ref-link-section-d2316419e1002">18</a></sup>. <i>Tth</i>SHMT crystallizes as a dimer with virtually equivalent active sites in protomers A and B, as seen in the cryogenic X-ray structure (PDB ID 2DKJ, unpublished). Similar to the other fold type I PLP-dependent enzymes, each protomer of <i>Tth</i>SHMT can be divided into large and small domains<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 1" title="Eliot, A. C. & Kirsch, J. F. Pyridoxal phosphate enzymes: mechanistic, structural, and evolutionary considerations. Annu Rev. Biochem 73, 383–415 (2004)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR1" id="ref-link-section-d2316419e1012">1</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 65" title="Schneider, G., Kack, H. & Lindqvist, Y. The manifold of vitamin B6 dependent enzymes. Structure 8, R1–R6 (2000)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR65" id="ref-link-section-d2316419e1015">65</a></sup>. The large domain (residues 33–284) is composed of a seven-strand mixed β-sheet surrounded by α-helices in an α/β/α sandwich fold (Fig. <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S4</a>). The small domain (residues 7–32 and 285–407) is made up of residues from both the N- and C-termini and the structure is dictated by anti-parallel β strands and α-helices in a two-fold α/β sandwich. The small domain is primarily responsible for establishing inter-subunit contacts<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 54" title="Trivedi, V. et al. Crystal structure of binary and ternary complexes of serine hydroxymethyltransferase from Bacillus stearothermophilus - Insights into the catalytic mechanism. J. Biol. Chem. 277, 17161–17169 (2002)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR54" id="ref-link-section-d2316419e1023">54</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 66" title="Scarsdale, J. N., Radaev, S., Kazanina, G., Schirch, V. & Wright, H. T. Crystal structure at 2.4 Å resolution of E. coli serine hydroxymethyltransferase in complex with glycine substrate and 5-formyl tetrahydrofolate11Edited by I. A. Wilson. J. Mol. Biol. 296, 155–168 (2000)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR66" id="ref-link-section-d2316419e1026">66</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 67" title="Szebenyi, D. M. E., Liu, X. W., Kriksunov, I. A., Stover, P. J. & Thiel, D. J. Structure of a murine cytoplasmic serine hydroxymethyltransferase quinonoid ternary complex: Evidence for asymmetric obligate dimers. Biochemistry 39, 13313–13323 (2000)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR67" id="ref-link-section-d2316419e1029">67</a></sup>. Each active site is located at the corresponding dimer interface and is constructed from residues of both protomers.</p> <p>To visualize the active site of SHMT at the atomic level of detail, we obtained a 2.3 Å neutron crystallographic structure of substrate-free <i>Tth</i>SHMT in the internal aldimine state jointly refined with 2.0 Å X-ray diffraction data (Table <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S1</a>, Supplementary Data <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM4">1</a>, PDB ID 8SUJ). We were unable to obtain neutron diffraction data from the P6<sub>5</sub>22 crystals of hSHMT2 because they diffracted X-rays at a synchrotron only to 2.5 Å (Table <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S2</a>). Therefore, to directly compare hSHMT2 with the joint XN structure of <i>Tth</i>SHMT, we also determined a 2.5 Å room-temperature X-ray structure of hSHMT2 in the internal aldimine state (Supplementary Data <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM5">2</a>, PBD ID 8SSJ), because all previous hSHMT2 X-ray structures were done at cryogenic temperatures<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 18" title="Giardina, G. et al. How pyridoxal 5’-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state. FEBS J. 282, 1225–1241 (2015)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR18" id="ref-link-section-d2316419e1057">18</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 37" title="Ducker, G. S. et al. Human SHMT inhibitors reveal defective glycine import as a targetable metabolic vulnerability of diffuse large B-cell lymphoma. Proc. Natl Acad. Sci. USA 114, 11404–11409 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR37" id="ref-link-section-d2316419e1060">37</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 62" title="Scaletti, E., Jemth, A. S., Helleday, T. & Stenmark, P. Structural basis of inhibition of the human serine hydroxymethyltransferase SHMT2 by antifolate drugs. FEBS Lett. 593, 1863–1873 (2019)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR62" id="ref-link-section-d2316419e1063">62</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 63" title="Ota, T. et al. Structural basis for selective inhibition of human serine hydroxymethyltransferase by secondary bile acid conjugate. iScience 24, 102036 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR63" id="ref-link-section-d2316419e1066">63</a></sup>. We accurately mapped the H atom positions (observed as D atoms), revealing the active site protonation states, H-bonding networks, water molecule orientations, and consequently electrostatics. Both diffraction datasets were collected at room temperature and pH of 5.5 from the same H/D exchanged protein crystal (Table <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S1</a>). In <i>Tth</i>SHMT, PLP is covalently bound to Lys226 (Lys280 in hSHMT2) through a Schiff base linkage with the side chain ζ-amino group forming the internal aldimine. Because the active site structures are identical within the experimental coordinate error of 0.3 Å in the protomers A and B of the <i>Tth</i>SHMT homodimer, we selected protomer B for our structural analyses below, unless stated otherwise. The pyridine nitrogen, N1, of the PLP cofactor, is protonated. Thus, it is positively charged (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig2">2a</a>). N1 participates in an H-bond with the negatively charged side chain carboxylate of Asp197 (Asp251 in hSHMT2) conserved in all fold type I PLP-dependent enzymes at an O···D distance of 1.7 Å. H-bond distances observed in the joint XN structures reported here are given henceforth as the distance between a D (or H) atom of an H-bond donor and a heavy atom of an H-bond acceptor unless otherwise specified. The Asp197 side chain is correctly situated to interact with PLP’s N1 by a network of H-bonds with Asn98 (Asn147 in hSHMT2), His125 (His174 in hSHMT2), and the backbone amide ND of Ala199 (Ala253 in hSHMT2). The pyridine N1 protonation has a significant role in PLP-dependent catalysis, increasing the efficiency of electron delocalization to the pyridine ring and leading to the stabilization of negatively charged reaction intermediates, but the enzyme microenvironment near N1 regulates its protonation state<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 68" title="Casasnovas, R., Salvà, A., Frau, J., Donoso, J. & Muñoz, F. Theoretical study on the distribution of atomic charges in the Schiff bases of 3-hydroxypyridine-4-aldehyde and alanine. The effect of the protonation state of the pyridine and imine nitrogen atoms. Chem. Phys. 355, 149–156 (2009)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR68" id="ref-link-section-d2316419e1083">68</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 69" title="Griswold, W. R. & Toney, M. D. Role of the pyridine nitrogen in pyridoxal 5’-phosphate catalysis: activity of three classes of PLP enzymes reconstituted with deazapyridoxal 5’-phosphate. J. Am. Chem. Soc. 133, 14823–14830 (2011)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR69" id="ref-link-section-d2316419e1086">69</a></sup>. Protonated N1 was also observed in the joint XN structure of aspartate aminotransferase (AAT), another fold type I PLP-dependent enzyme<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 44" title="Dajnowicz, S. et al. Direct visualization of critical hydrogen atoms in a pyridoxal 5’-phosphate enzyme. Nat. Commun. 8, 955 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR44" id="ref-link-section-d2316419e1090">44</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 70" title="Mueser, T. C., Drago, V., Kovalevsky, A. & Dajnowicz, S. Pyridoxal 5’-phosphate dependent reactions: analyzing the mechanism of aspartate aminotransferase. Methods Enzymol. 634, 333–359 (2020)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR70" id="ref-link-section-d2316419e1093">70</a></sup>, where it is similarly H-bonded to a conserved aspartate residue. Because the active sites of <i>Tth</i>SHMT and hSHMT2 are conserved we propose that N1 is also protonated in hSHMT2, participating in an H-bond with Asp251 having the N···O distance of 2.9 Å (Fig. <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S5</a>).</p> <div class="c-article-section__figure js-c-reading-companion-figures-item" data-test="figure" data-container-section="figure" id="figure-2" data-title="Neutron scattering length density maps for TthSHMT active site residues for the joint XN internal aldimine structure."> <figure> <figcaption> <b id="Fig2" class="c-article-section__figure-caption" data-test="figure-caption-text">Fig. 2: Neutron scattering length density maps for <i>Tth</i>SHMT active site residues for the joint XN internal aldimine structure.</b> </figcaption> <div class="c-article-section__figure-content"> <div class="c-article-section__figure-item"> <a class="c-article-section__figure-link" data-test="img-link" data-track="click" data-track-label="image" data-track-action="view figure" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9/figures/2?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" rel="nofollow"> <picture> <source type="image/webp" srcset="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://media.springernature.com/lw685/springer-static/image/art%253A10.1038%252Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig2_HTML.png?as%3Dwebp"> <img aria-describedby="Fig2" src="//media.springernature.com/lw685/springer-static/image/art%3A10.1038%2Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig2_HTML.png" alt="figure 2" loading="lazy" width="685" height="825"> </picture></a> </div> <div class="c-article-section__figure-description" data-test="bottom-caption" id="figure-2-desc"> <p>The 2F<sub>O</sub>-F<sub>C</sub> neutron scattering length density contoured at 1σ level is depicted by wheat mesh. The omit F<sub>O</sub>-F<sub>C</sub> difference neutron scattering length density map contoured at 2 σ level is represented by magenta mesh. D atoms are shown in green, and H atoms are white. <b>a</b> N1 of the PLP cofactor is protonated (positively charged), but Schiff base N<sub>SB</sub> is not (neutral). An H-bonding network with Asn98, His125, and Ala199 fixes the position of deprotonated Asp197 (negatively charged) that forms an H-bond with N1. Above PLP, the side chain of Ala199 further stabilizes PLP position through C-H···π interactions. <b>b</b> O3′ of PLP is deprotonated with a partial negative charge stabilized through an unconventional C-H···O bond with His200. A network of H-bonds made by neutral His200 and His312 connect O3′ to the main chain amide ND of His312. <b>c</b> A sulfate ion accommodates the amino acid substrate binding site, and its position is stabilized through several H-bonds. <b>d</b> The pyridine ring of PLP is sandwiched between His122 and Ala199 making π-π stacking and C-H···π interactions. His122, positioned on the <i>re</i> face of the cofactor, is neutral and its imidazole group accepts D atoms from the side chain and amide backbone of Thr124 in a bifurcated H-bond. <b>e</b> The phosphate group of PLP binds in the phosphate binding pocket made up of the side chains of Tyr51* and Ser95, the amide backbone of Gly94, Ser95, and Gly258, and three crystallographic waters.</p> </div> </div> <div class="u-text-right u-hide-print"> <a class="c-article__pill-button" data-test="article-link" data-track="click" data-track-label="button" data-track-action="view figure" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9/figures/2?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track-dest="link:Figure2 Full size image" aria-label="Full size image figure 2" rel="nofollow"><span>Full size image</span> <svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"> <use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-chevron-right-small" /> </svg></a> </div> </figure> </div> <p>The Schiff base nitrogen, N<sub>SB</sub>, of the PLP cofactor is found to be not protonated, thus neutral, and the C=N bond is rotated by 35° and 29° above the plane of the pyridine ring on the <i>si</i> face of the active site in protomers A and B, respectively. N<sub>SB</sub> makes no interactions with the active site residues. In hSHMT2, the Schiff base rotates to a much greater extent, with the corresponding dihedral angles in protomers A and B of 67° and 73°(Fig. <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S6</a>). The Schiff base out-of-plane rotation appears to be the attribute of the N<sub>SB</sub> neutrality as was also observed in the joint XN structure of AAT<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 44" title="Dajnowicz, S. et al. Direct visualization of critical hydrogen atoms in a pyridoxal 5’-phosphate enzyme. Nat. Commun. 8, 955 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR44" id="ref-link-section-d2316419e1172">44</a></sup>. Therefore, the above considerations point to the high probability of N<sub>SB</sub> atom not being protonated in hSHMT2 either. Interestingly, in the high-resolution cryogenic X-ray diffraction structure of <i>Tth</i>SHMT (PDB ID 2DKJ) this torsion angle is reduced to 26° and 15° in protomers A and B, respectively. Protonation of N<sub>SB</sub> promotes the Schiff base to be more co-planar with the pyridine ring due to an H-bond formation with the phenolic oxygen O3′, as demonstrated by previous DFT calculations<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 9" title="Richard, J. P., Amyes, T. L., Crugeiras, J. & Rios, A. Pyridoxal 5 ’-phosphate: electrophilic catalyst extraordinaire. Curr. Opin. Chem. Biol. 13, 475–483 (2009)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR9" id="ref-link-section-d2316419e1183">9</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 44" title="Dajnowicz, S. et al. Direct visualization of critical hydrogen atoms in a pyridoxal 5’-phosphate enzyme. Nat. Commun. 8, 955 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR44" id="ref-link-section-d2316419e1186">44</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 71" title="Casasnovas, R. et al. C-H Activation in Pyridoxal-5 ’-phosphate Schiff bases: the role of the imine nitrogen. A combined experimental and computational study. J. Phys. Chem. B 116, 10665–10675 (2012)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR71" id="ref-link-section-d2316419e1189">71</a></sup>. It is thus reasonable to suggest that N<sub>SB</sub> may be protonated at lower temperatures, pointing to the possible temperature dependence of the Schiff base protonation state. To gain more insight into the energy profile of the Schiff base rotation around the pyridine ring, we performed DFT calculations on the PLP-Lys model (Fig. <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S7</a>). Indeed, when N<sub>SB</sub> is not protonated the potential energy surface is shallow with two local energy minima at ~21° and −21° in agreement with the observed dihedral angles in the joint XN structures. The global minimum occurs when C=N bond is rotated away from O3′ and is coplanar with the pyridine ring, a geometry that cannot be achieved in the protein due to geometric constraints of Lys being connected to other residues. In sharp contrast, the protonated Schiff base shows a very different potential energy profile, with the global minimum found for the C=N bond fully coplanar with the pyridine ring facing the deprotonated O3′.</p> <p>The nuclear (neutron scattering length) density near the phenolic oxygen O3′ indicates the absence of a D atom. Therefore O3′ is observed as a deprotonated phenolate in the current joint XN structure. The resulting negative charge on O3′ is delocalized through resonance with the protonated pyridine ring. Both 2F<sub>O</sub>-F<sub>C</sub> and omit F<sub>O</sub>-F<sub>C</sub> nuclear density maps clearly show that O3′ engages in an unconventional C-H···O hydrogen bond with Cδ2 of His200 imidazole (His254 in hSHMT2) with the distance of 2.0 Å (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig2">2b</a>). This orients the protonated Nε2 of His200 to donate a 1.7 Å H-bond with the sulfate ion (SO<sub>4</sub><sup>2-</sup>) located in the substrate binding pocket near Arg358 (Arg425 in hSHMT2) (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig2">2c</a>). The sulfate is present in the crystallization solutions and its presence in the structure is an artifact of the crystallization conditions. In contrast to the current joint XN structure, in some previously published X-ray crystal structures of SHMT from other species, the His residues equivalent to <i>Tth</i>SHMT His200 were incorrectly modeled to participate in H-bonds with O3′ with their Nδ1 atoms<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 53" title="Renwick, S. B., Snell, K. & Baumann, U. The crystal structure of human cytosolic serine hydroxymethyltransferase: a target for cancer chemotherapy. Structure 6, 1105–1116 (1998)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR53" id="ref-link-section-d2316419e1225">53</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 54" title="Trivedi, V. et al. Crystal structure of binary and ternary complexes of serine hydroxymethyltransferase from Bacillus stearothermophilus - Insights into the catalytic mechanism. J. Biol. Chem. 277, 17161–17169 (2002)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR54" id="ref-link-section-d2316419e1228">54</a></sup>. In <i>Tth</i>SHMT, His200 is found to be singly protonated, thus neutral, its Nδ1 accepting a 1.9 Å H-bond with Nε2 of His312 (His380 in hSHMT2). Furthermore, His312 Nε2 faces its own main chain amide ND to form a 2.2 Å H-bond and is also singly protonated and neutral. Thus, a network of unconventional C-H···O and conventional N-H···N H-bonds (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig2">2b</a>) that connects the negatively charged PLP O3′ to the His312 main chain ensures the neutral charge of both His200 and His312, which would undoubtedly remain neutral at the physiological pH of 7.4. The H-bond network connecting PLP O3′ to the main chain NH of His380 is identical in hSHMT2, suggesting the same protonation states of O3′, His254, and His380 in the human enzyme as observed in <i>Tth</i>SHMT.</p> <p>Found on the <i>re</i> face of PLP, the sulfate ion mimics substrate binding, occupying the presumed substrate binding pocket. The sulfate position is stabilized by an H-bonding network consisting of Ser31 (Ser76 in hSHMT2), His200, Arg358, Tyr61* (Tyr106* in hSHMT2, the asterisk denotes that the residue belongs to the other protomer), and two water molecules (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig2">2c</a>). The sulfate participates in a salt bridge with Arg358, with H-bond distances of 1.9 Å and 2.0 Å. Ser31 and Tyr61* donate their hydroxyl D atoms in 2.0 and 1.9 Å H-bonds with the sulfate, respectively. The two water molecules coordinate the sulfate with H-bond distances of 1.8 and 1.9 Å and link it to Glu53* (Glu98 in hSHMT2). Glu53, a conserved active site residue that is proposed to take part in the THF-dependent cleavage of L-Ser as a general acid/base catalyst<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 55" title="Szebenyi, D. M. E., Musayev, F. N., di Salvo, M. L., Safo, M. K. & Schirch, V. Serine hydroxymethyltransferase: role of Glu75 and evidence that serine is cleaved by a retroaldol mechanism. Biochemistry 43, 6865–6876 (2004)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR55" id="ref-link-section-d2316419e1252">55</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 56" title="Schirch, V. & Szebenyi, D. M. Serine hydroxymethyltransferase revisited. Curr. Opin. Chem. Biol. 9, 482–487 (2005)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR56" id="ref-link-section-d2316419e1255">56</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 58" title="Rao, N. A., Ambili, M., Jala, V. R., Subramanya, H. S. & Savithri, H. S. Structure-function relationship in serine hydroxymethyltransferase. Biochim. Biophys. Acta-Proteins Proteom. 1647, 24–29 (2003)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR58" id="ref-link-section-d2316419e1258">58</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 72" title="Rajaram, V. et al. Structure determination and biochemical studies on Bacillus stearothermophilus E53Q serine hydroxymethyltransferase and its complexes provide insights on function and enzyme memory. FEBS J. 274, 4148–4160 (2007)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR72" id="ref-link-section-d2316419e1261">72</a></sup>, is deprotonated and positioned on the <i>re</i> face of PLP near the substrate binding pocket (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig2">2c</a>). We believe Glu98 in hSHMT2 is also deprotonated because the electrostatic environment is the same in the substrate binding pocket of the human enzyme. In our room-temperature structure of hSHMT2, the substrate binding pocket is occupied by a chloride anion, Cl<sup>−</sup>. The presence of Cl<sup>−</sup> can be physiologically relevant as intracellular Cl<sup>−</sup> concentration can be ~20–100 mM<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 73" title="Shcheynikov, N. et al. Intracellular Cl- as a signaling ion that potently regulates Na+/HCO3- transporters. Proc. Natl Acad. Sci. USA 112, E329–E337 (2015)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR73" id="ref-link-section-d2316419e1278">73</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 74" title="Jahn, S. C., Rowland-Faux, L., Stacpoole, P. W. & James, M. O. Chloride concentrations in human hepatic cytosol and mitochondria are a function of age. Biochem. Biophys. Res Commun. 459, 463–468 (2015)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR74" id="ref-link-section-d2316419e1281">74</a></sup>. The affinity of this pocket for anionic ligands is probably dictated by the nearby positively charged arginine residue, Arg358 in <i>Tth</i>SHMT or Arg425 in hSHMT2. In contrast, a glycerol molecule is found in the substrate binding pocket in the X-ray structure of hSHMT2 obtained under cryogenic conditions with glycerol added as the cryoprotectant<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 18" title="Giardina, G. et al. How pyridoxal 5’-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state. FEBS J. 282, 1225–1241 (2015)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR18" id="ref-link-section-d2316419e1288">18</a></sup>. Glycerol is normally used at concentrations of ~2 M for cryoprotection of protein crystals and can undoubtedly outcompete an anion for binding in this pocket.</p> <p>The PLP pyridine ring is sandwiched between Ala199 (Ala253 in hSHMT2) on the <i>si</i> face and His122 (His171 in hSHMT2) on the <i>re</i> face (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig2">2d</a>). The side chain of Ala199 makes C-H···π interactions with the π-conjugated system of the pyridine ring, with the heavy atom distances in the range of 3.5–3.9 Å. This residue is conserved in fold type I PLP-dependent enzymes. Site-directed mutagenesis studies suggest the residue at this position may help modulate the pK<sub>a</sub> of the internal aldimine N<sub>SB</sub><sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 75" title="Eliot, A. C. & Kirsch, J. F. Modulation of the internal aldimine pK(a)’s of 1-aminocyclopropane-1-carboxylate synthase and aspartate arninotransferase by specific active site residues. Biochemistry 41, 3836–3842 (2002)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR75" id="ref-link-section-d2316419e1307">75</a></sup>. The His122 imidazole ring sits parallel to the pyridine ring in a π-π stacking interaction with distances of 3.5–3.7 Å between the heavy atoms. His122 is singly protonated on Nε2 (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig2">2c, d</a>). The neutral charge of His122 is the result of the imidazole Nδ1 accepting a bifurcated H-bond with the side chain hydroxyl and main chain amide ND of Thr124 (Thr173 in hSHMT2) with the distances of 2.0 and 2.2 Å, respectively. His122 also donates a 1.8 Å H-bond with a water molecule that mediates the imidazole interactions with the sulfate and PLP phosphate group (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig2">2c</a>). Again, in hSHMT2 His171 and Ala253 make very similar interactions with PLP and H-bonds with adjacent residues, allowing us to postulate that the His171 protonation state is the same as that of His122 in <i>Tth</i>SHMT (Fig. <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S5</a>).</p> <p>In addition to making a covalent bond with the catalytic Lys226 and an H-bond between pyridine N1 and Asp197, the PLP position in the active site is further stabilized through an intricate network of H-bonds and water-mediated interactions made by the phosphate group with the phosphate binding pocket. In <i>Tth</i>SHMT, the phosphate binding pocket is composed of the side chains of Ser95 (Ser144 in hSHMT2) and Tyr51* (Tyr96 in hSHMT2), the main chain amide NDs of Gly94 (Gly143 in hSHMT2), Ser95, and Gly258* (Gly326 in hSHMT2), and three water molecules. The phosphate group makes 1.8 and 1.9 Å hydrogen bonds with Ser95 and Tyr51* hydroxyls, but somewhat longer 2.0–2.3 Å H-bonds with the main chain amides (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig2">2e</a>). The water molecules mediate the phosphate group interactions with the main chain carbonyl of Gly258*, and with the side chain of His122 mentioned above.</p> <h3 class="c-article__sub-heading" id="Sec4">L-Ser binds as a zwitterion in the <i>pre</i>-Michaelis complex</h3> <p>To obtain a complex with the bound substrate, we repurposed the <i>Tth</i>SHMT crystal from the first neutron diffraction experiment by soaking it with the deuterated serine substrate, L-Ser-d<sub>7</sub> at 500 mM concentration. We then collected a 2.3 Å room-temperature neutron diffraction dataset on this crystal. Joint XN refinement was performed using 2.0 Å room-temperature X-ray diffraction data collected on the same crystal immediately after the neutron experiment. Although it was expected that L-Ser-d<sub>7</sub> would displace Lys226 in the Schiff base linkage to PLP to form the external aldimine, the intact internal aldimine was observed in this structure with the sulfate ions still occupying the substrate binding sites in both protomers. However, we observed L-Ser-d<sub>7</sub> bound in a pocket on the periphery of the active site in protomer A, with the substrate positioned in front of the sulfate ion (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig3">3a, b</a>; Supplementary Data <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM6">3</a>, PBD ID 8SUI). We, therefore, call this complex, <i>Tth</i>SHMT/L-Ser, a <i>pre</i>-Michaelis complex, in which both protomers display the same open conformation observed in the substrate-free internal aldimine joint XN structure. The enzyme active site entrance resembles a funnel, with a wide opening that narrows down going deeper towards PLP. The peripheral binding site of L-Ser-d<sub>7</sub> is where various ligands, including THF analogs and non-THF high-affinity inhibitors such as SHIN-1, are located in the structures of SHMT from different sources<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 37" title="Ducker, G. S. et al. Human SHMT inhibitors reveal defective glycine import as a targetable metabolic vulnerability of diffuse large B-cell lymphoma. Proc. Natl Acad. Sci. USA 114, 11404–11409 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR37" id="ref-link-section-d2316419e1369">37</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 62" title="Scaletti, E., Jemth, A. S., Helleday, T. & Stenmark, P. Structural basis of inhibition of the human serine hydroxymethyltransferase SHMT2 by antifolate drugs. FEBS Lett. 593, 1863–1873 (2019)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR62" id="ref-link-section-d2316419e1372">62</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 76" title="Ruszkowski, M. et al. Structural basis of methotrexate and pemetrexed action on serine hydroxymethyltransferases revealed using plant models. Sci. Rep.-UK 9, 19614 (2019)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR76" id="ref-link-section-d2316419e1375">76</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 77" title="Makino, Y. et al. Serine hydroxymethyltransferase as a potential target of antibacterial agents acting synergistically with one-carbon metabolism-related inhibitors. Commun. Biol. 5, 619 (2022)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR77" id="ref-link-section-d2316419e1378">77</a></sup>; however, amino acid substrates have not been captured previously in this site.</p> <div class="c-article-section__figure js-c-reading-companion-figures-item" data-test="figure" data-container-section="figure" id="figure-3" data-title="Binding of L-Ser-d7 to the peripheral binding site within the funnel-shaped active site cavity as observed in the joint XN structure of TthSHMT/L-Ser pre-Michaelis complex."> <figure> <figcaption> <b id="Fig3" class="c-article-section__figure-caption" data-test="figure-caption-text">Fig. 3: Binding of L-Ser-d<sub>7</sub> to the peripheral binding site within the funnel-shaped active site cavity as observed in the joint XN structure of <i>Tth</i>SHMT/L-Ser <i>pre</i>-Michaelis complex.</b> </figcaption> <div class="c-article-section__figure-content"> <div class="c-article-section__figure-item"> <a class="c-article-section__figure-link" data-test="img-link" data-track="click" data-track-label="image" data-track-action="view figure" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9/figures/3?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" rel="nofollow"> <picture> <source type="image/webp" srcset="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://media.springernature.com/lw685/springer-static/image/art%253A10.1038%252Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig3_HTML.png?as%3Dwebp"> <img aria-describedby="Fig3" src="//media.springernature.com/lw685/springer-static/image/art%3A10.1038%2Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig3_HTML.png" alt="figure 3" loading="lazy" width="685" height="567"> </picture></a> </div> <div class="c-article-section__figure-description" data-test="bottom-caption" id="figure-3-desc"> <p><b>a</b> L-Ser-d<sub>7</sub> is found at the entrance to the active site cavity in front of the sulfate ion. <b>b</b> The α-amino group of L-Ser-d<sub>7</sub> faces a hydrophobic patch (Leu117 and Leu123) and its carboxyl group is directed towards the bulk solvent. The side chain hydroxyl of L-Ser-d<sub>7</sub> makes an H-bond with Tyr61*. <b>c</b> The 2F<sub>O</sub>-F<sub>C</sub> neutron scattering length density in the L-Ser-d<sub>7</sub> binding site contoured at 1σ level is depicted by wheat mesh. In addition to an H-bond with Tyr61*, the substrate has a water-mediated interaction with Glu53*.</p> </div> </div> <div class="u-text-right u-hide-print"> <a class="c-article__pill-button" data-test="article-link" data-track="click" data-track-label="button" data-track-action="view figure" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9/figures/3?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track-dest="link:Figure3 Full size image" aria-label="Full size image figure 3" rel="nofollow"><span>Full size image</span> <svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"> <use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-chevron-right-small" /> </svg></a> </div> </figure> </div> <p>In protomer A of <i>Tth</i>SHMT/L-Ser, L-Ser-d<sub>7</sub> is observed in the zwitterionic state with the protonated α-amino group facing a hydrophobic patch made up of Leu117 (Leu166 in hSHMT2), Leu123 (Leu172 in hSHMT2), and Phe252* (Phe320* in hSHMT2), whereas the deprotonated carboxyl group is directed into the bulk solvent (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig3">3b</a>). The side chain hydroxyl is positioned towards the substrate binding site next to the sulfate ion. The hydroxyl group of L-Ser-d<sub>7</sub> donates its D atom in a weak bifurcated H-bond with a water molecule (2.20 Å), mediating its contact with Glu53*, and the sulfate ion (2.6 Å) (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig3">3c</a>). The hydroxyl group of Tyr61* (Tyr106* in hSHMT2) rotates away from the sulfate ion to lose its H-bond as found in the substrate-free <i>Tth</i>SHMT structure, and now makes a 2.2 Å H-bond with the L-Ser hydroxyl oxygen. It is important to note that in the <i>Tth</i>SHMT/L-Ser joint XN structure, we found the same protonation states in the active sites of both protomers that were observed in the substrate-free structure. The N<sub>SB</sub> atoms of the Schiff bases are neutral, as are all the His residues, whereas the pyridine N1 is protonated. Thus, the non-covalent binding of the substrate in the <i>pre</i>-Michaelis complex does not disturb the locations of H atoms and hence the electrostatics of the active site cavity.</p> <h3 class="c-article__sub-heading" id="Sec5">D-Ser occupies the substrate binding site in a <i>pseudo</i>-Michaelis complex</h3> <p>In the <i>Tth</i>SHMT joint XN structures described above, the position occupied by the sulfate ion (or Cl<sup>–</sup> in hSHMT2) in the active sites is presumably the binding site for the amino acid substrate en route to generate the external aldimine intermediate. To capture a substrate bound at this site, we soaked a <i>Tth</i>SHMT crystal with D-Ser and obtained a 1.8 Å room-temperature X-ray structure of the complex (Supplementary Data <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM7">4</a>, PBD ID 8SSY). The crystal soaking experiment produced a complex with D-Ser in protomer A replacing the sulfate, whereas protomer B retained the sulfate ion in the substrate binding site. Both protomers remained in the open conformation. D-Ser, the enantiomer of the physiological substrate L-Ser, did not proceed to react with C4´ of the internal aldimine thus generating a <i>pseudo</i>-Michaelis complex, <i>Tth</i>SHMT/D-Ser. It was not however possible to produce crystals of this complex of sufficient volume for neutron diffraction experiments.</p> <p>H-bond interactions made by the D-Ser carboxylate and side chain hydroxyl groups orient the substrate enantiomer in the active site in a specific fashion (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig4">4a</a>). Arg358 acts as the primary anchoring point, forming a salt bridge with the D-Ser carboxylate by making two H-bonds with the N···O distances of 2.7 Å and 2.8 Å. Tyr61* that interacts with the D-Ser hydroxyl adopts two alternate conformations (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig4">4b</a>). In one conformation, at 57% occupancy, the Tyr61* phenolic hydroxyl is shifted towards the hydroxyl group of D-Ser with an O···O distance of 2.6 Å. In the other conformation, at 43% occupancy, the Tyr61* phenol is rotated slightly away to form H-bonds with the D-Ser carboxylate and Ser31 side chain with both distances of 2.8 Å, resulting in a longer interaction of 3.1 Å with the D-Ser hydroxyl group. Tyr61 occupies a single conformation in each of the <i>Tth</i>SHMT joint XN structures, therefore its positional disorder in <i>Tth</i>SHMT/D-Ser is due to D-Ser binding. In the <i>pseudo</i>-Michaelis complex, Glu53* was observed within an H-bond distance of 2.9 Å to the D-Ser hydroxyl. All these H-bonds would probably be retained when L-Ser binds in the Michaelis complex before its nucleophilic α-amino group attacks C4´ of the internal aldimine for the reaction to proceed to the external aldimine. Importantly, the H-bonds with the residues corresponding to Arg358, Glu53*, and Tyr61* are also observed in the X-ray structures of the L-Ser external aldimine state for SHMTs from different species (PDB IDs: 4PFN, 6CDI)<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Makino, Y. et al. Serine hydroxymethyltransferase as a potential target of antibacterial agents acting synergistically with one-carbon metabolism-related inhibitors. Commun. Biol. 5, 619 (2022)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR77" id="ref-link-section-d2316419e1509">77</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Chitnumsub, P. et al. Structures of Plasmodium vivax serine hydroxymethyltransferase: implications for ligand-binding specificity and functional control. Acta Crystallogr D. 70, 3177–3186 (2014)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR78" id="ref-link-section-d2316419e1509_1">78</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 79" title="Ruszkowski, M., Sekula, B., Ruszkowska, A. & Dauter, Z. Chloroplastic serine hydroxymethyltransferase from medicago truncatula: a structural characterization. Front Plant Sci. 9, 584 (2018)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR79" id="ref-link-section-d2316419e1512">79</a></sup>, indicating minimal structural rearrangements upon the external aldimine formation.</p> <div class="c-article-section__figure js-c-reading-companion-figures-item" data-test="figure" data-container-section="figure" id="figure-4" data-title="Binding of D-Ser to the substrate binding site as observed in the room-temperature X-ray structure of TthSHMT/D-Ser pseudo-Michaelis complex."> <figure> <figcaption> <b id="Fig4" class="c-article-section__figure-caption" data-test="figure-caption-text">Fig. 4: Binding of D-Ser to the substrate binding site as observed in the room-temperature X-ray structure of <i>Tth</i>SHMT/D-Ser <i>pseudo</i>-Michaelis complex.</b> </figcaption> <div class="c-article-section__figure-content"> <div class="c-article-section__figure-item"> <a class="c-article-section__figure-link" data-test="img-link" data-track="click" data-track-label="image" data-track-action="view figure" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9/figures/4?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" rel="nofollow"> <picture> <source type="image/webp" srcset="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://media.springernature.com/lw685/springer-static/image/art%253A10.1038%252Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig4_HTML.png?as%3Dwebp"> <img aria-describedby="Fig4" src="//media.springernature.com/lw685/springer-static/image/art%3A10.1038%2Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig4_HTML.png" alt="figure 4" loading="lazy" width="685" height="342"> </picture></a> </div> <div class="c-article-section__figure-description" data-test="bottom-caption" id="figure-4-desc"> <p>The 2F<sub>O</sub>-F<sub>C</sub> electron density contoured at 1σ level is depicted by gray mesh. <b>a</b> D-Ser makes numerous H-bonds with the active site residues. Tyr61* adopts two alternate conformations which make different substrate interactions depicted in panel (<b>b</b>). The D-Ser α-amino group is oriented away from C4′, presumably preventing the formation of the external aldimine. <b>b</b> Zoomed-in view of Tyr61* interactions with D-Ser.</p> </div> </div> <div class="u-text-right u-hide-print"> <a class="c-article__pill-button" data-test="article-link" data-track="click" data-track-label="button" data-track-action="view figure" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9/figures/4?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track-dest="link:Figure4 Full size image" aria-label="Full size image figure 4" rel="nofollow"><span>Full size image</span> <svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"> <use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-chevron-right-small" /> </svg></a> </div> </figure> </div> <p>In the <i>Tth</i>SHMT/D-Ser complex, the D-Ser α-amino group is 3.0 Å away from N<sub>SB</sub> but is angled away from C4′ at a distance of 3.5 Å, possibly making the nucleophilic attack unfavorable and producing the stable <i>pseudo</i>-Michaelis complex. In contrast, D-Ser readily reacted with the internal aldimine of <i>Plasmodium vivax</i> SHMT to generate the corresponding external aldimine<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 78" title="Chitnumsub, P. et al. Structures of Plasmodium vivax serine hydroxymethyltransferase: implications for ligand-binding specificity and functional control. Acta Crystallogr D. 70, 3177–3186 (2014)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR78" id="ref-link-section-d2316419e1570">78</a></sup>. Because H atoms cannot be observed in the <i>Tth</i>SHMT/D-Ser X-ray structure, the protonation states of the cofactor and D-Ser cannot be determined. Therefore, we do not know whether the substrate would still be zwitterionic in the <i>pseudo</i>-Michaelis complex as observed in our joint XN structure of the <i>pre</i>-Michaelis complex. Previously, based on the XN structures of AAT in the internal and external aldimine states<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 44" title="Dajnowicz, S. et al. Direct visualization of critical hydrogen atoms in a pyridoxal 5’-phosphate enzyme. Nat. Commun. 8, 955 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR44" id="ref-link-section-d2316419e1584">44</a></sup>, we suggested that the protonated α-amino group of an amino acid substrate might transfer a proton to N<sub>SB</sub>, generating the reactive nucleophilic amine, in the Michaelis complex. In <i>Tth</i>SHMT/D-Ser, the D-Ser α-amino group makes a 3.0 Å H-bond with His200 Nε2 that is protonated, indicating the amine may already be in the reactive state. Moreover, the Schiff base out-of-plane dihedral relative to the pyridine ring is flattened to 20° indicative of N<sub>SB</sub> being protonated and positively charged. The corresponding Schiff base dihedral in protomer B is 26°, similar to the value of 29° found in protomer B of the substrate-free <i>Tth</i>SHMT XN structure.</p> <h3 class="c-article__sub-heading" id="Sec6">Protonation of Glu residues</h3> <p>Outside of the active site, we detected three protonated glutamate residues in the <i>Tth</i>SHMT homodimer (Fig. <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S8</a>). The buried Glu261 is protonated in both protomers A and B on Oε2 atoms forming H-bonds of 1.7 Å and 1.6 Å, respectively, with Glu71 from the neighboring α-helix. The O···O distances of these H-bonds are 2.7 (protomer A) and 2.5 Å (protomer B). We, therefore, observed fully localized D atoms participating in short conventional H-bonds in the Glu-Glu pairs. Similar observations were made in high-resolution X-ray structures of protein DJ-1 (Lin et al. 2017) and in the neutron structure of HIV-1 protease gemdiol intermediate<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 52" title="Kumar, M. et al. Visualizing tetrahedral oxyanion bound in HIV-1 protease using neutrons: implications for the catalytic mechanism and drug design. ACS Omega 5, 11605–11617 (2020)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR52" id="ref-link-section-d2316419e1613">52</a></sup>. Conversely, in concanavalin A and HIV-1 protease/drug complexes<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 80" title="Gerlits, O. O., Coates, L., Woods, R. J. & Kovalevsky, A. Mannobiose binding induces changes in hydrogen bonding and protonation states of acidic residues in concanavalin a as revealed by neutron crystallography. Biochemistry 56, 4747–4750 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR80" id="ref-link-section-d2316419e1617">80</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 81" title="Gerlits, O. et al. Room temperature neutron crystallography of drug resistant HIV-1 protease uncovers limitations of X-ray structural analysis at 100 K. J. Med. Chem. 60, 2018–2025 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR81" id="ref-link-section-d2316419e1620">81</a></sup> D atoms within Glu-Asp or Asp-Asp pairs, respectively, were found participating in the apparent low-barrier hydrogen bonds manifested by the D atoms located midway between the oxygen atoms. It is possible that the H-bonding and electrostatic environment around the carboxylic groups modulate the nature of the formed H-bond. For example, in <i>Tth</i>SHMT, positively charged Arg59 is positioned near Glu71 donating its D atoms in two H-bonds with Oε1. Therefore, Glu71 Oε1 forms a bifurcated H-bond with Arg59 and protonated Glu261, possibly driving the localization of D on Glu261 Oε2. In hSHMT2, residue 329 corresponding to <i>Tth</i>SHMT Glu261 is substituted to a smaller asparagine, which makes a water-mediated contact with Glu116 (Glu71 in <i>Tth</i>SHMT) unable to form a direct H-bond.</p> <p>Another protonated glutamic acid residue, Glu65 in protomer A of <i>Tth</i>SHMT, participates in a superficial long-range, electrostatic interaction with Asp333* from the small domain of protomer B (O···O distance of ~4 Å). In protomer B, Glu65* is not protonated, curling in to make an H-bond with its own main chain amide ND, and is >5 Å away from the Asp333 carboxylate of protomer A. Asp333 is not conserved in hSHMT2, where it is Glu401. Although glutamate has a larger side chain compared to aspartate, Glu401 is >4 Å away from Glu110* for all pairs of these residues in hSHMT2 homotetramer.</p> </div> </div> </section> <section data-title="Discussion"> <div class="c-article-section" id="Sec7-section"> <h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Sec7">Discussion</h2> <div class="c-article-section__content" id="Sec7-content"> <p>Many biochemical reactions proceeding inside active sites of enzymes are governed by general acid-base catalysis. The catalytic reaction is typically facilitated by proton transfer events that occur along the reaction pathway. Moreover, ligand (substrate or inhibitor) binding in the enzyme active site may be accompanied by protonation state changes that alter the electrostatic landscape of the binding site relative to its initial unbound state. As a result, to fully understand enzyme catalysis and to inform structure-based drug design it is essential to capture these protonation and deprotonation events by observing the locations and movement of H atoms before and after a ligand binds and throughout the catalytic reaction. The H atom positions determine the protonation states and electrical charges of amino acid residues and ligands, and hence electrostatics, within the enzyme active sites. In this work, we utilized the power of neutrons to directly detect and visualize the positions of H atoms in a protein structure to study the catalytic mechanism and substrate binding for <i>Tth</i>SHMT enzyme. We extended the structural and mechanistic insights gleaned from the joint XN structures to the homologous human enzyme hSHMT2 whose active site structure and amino acid composition is conserved relative to that of <i>Tth</i>SHMT.</p> <p>The serine substrate enters the <i>Tth</i>SHMT active site through a funnel-shaped entrance first being captured at the peripheral substrate binding site (<i>pre</i>-Michaelis state) and then tracked deeper to the cationic substrate binding site (Michaelis state) (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig5">5a</a>). We observed in the room-temperature joint XN structure of <i>Tth</i>SHMT/L-Ser complex that L-Ser is captured in the zwitterionic state (<sup>+</sup>NH<sub>3</sub>-Cα-COO<sup>−</sup>) at the peripheral substrate binding site that is mainly hydrophobic and exposed to the bulk solvent. The L-Ser position is stabilized by the substrate’s hydroxyl making a direct H-bond with Tyr61* and a water-mediated contact with Glu53*. The Tyr61* phenolic hydroxyl rotates to donate its D in an H-bond with L-Ser from its position in the substrate-free structure, where it formed an H-bond with the sulfate anion. Previous structural and mutagenesis data suggested that Tyr61 plays a role in the interconversion of the open and closed conformational states of the active site<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 82" title="Contestabile, R. et al. Role of tyrosine 65 in the mechanism of serine hydroxymethyltransferase. Biochemistry 39, 7492–7500 (2000)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR82" id="ref-link-section-d2316419e1677">82</a></sup>. We further tracked the substrate deeper into the active site. In the <i>Tth</i>SHMT/D-Ser room-temperature X-ray structure, D-Ser occupies the substrate binding site that evidently has some affinity to anions, as sulfate is found in <i>Tth</i>SHMT, and chloride is observed in hSHMT2 room-temperature structures. Therefore, this binding site, likely occupied in the Michaelis complex, can be called a cationic substrate binding site. The D-Ser α-amino group is 3.5 Å away from PLP C4´ and is expected to be positioned closer in the actual Michaelis complex with L-Ser. At the cationic substrate binding site, D-Ser is anchored by a salt bridge with Arg358 and by direct H-bonds with Glu53* and Tyr61*, the H-bonds anticipated to be conserved in the Michaelis complex to orient the L-Ser substrate correctly to carry out a nucleophilic attack on the PLP Schiff base C4´ atom. Interestingly, SHIN-1, a high-affinity inhibitor of hSHMT2, binds at the peripheral substrate binding site in the X-ray structure of <i>E. faecium</i> SHMT displacing the Tyr61* side chain by a bulky isopropyl group<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 77" title="Makino, Y. et al. Serine hydroxymethyltransferase as a potential target of antibacterial agents acting synergistically with one-carbon metabolism-related inhibitors. Commun. Biol. 5, 619 (2022)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR77" id="ref-link-section-d2316419e1691">77</a></sup>. Based on our structures, we propose that the future inhibitor design could take advantage of the existence of the two substrate binding sites that provide opportunities for additional H-bonds and electrostatic interactions to be made by designed inhibitors.</p> <div class="c-article-section__figure js-c-reading-companion-figures-item" data-test="figure" data-container-section="figure" id="figure-5" data-title="Proposed L-Ser substrate pathway through the TthSHMT active site cavity and the mechanism of the external aldimine formation."> <figure> <figcaption> <b id="Fig5" class="c-article-section__figure-caption" data-test="figure-caption-text">Fig. 5: Proposed L-Ser substrate pathway through the <i>Tth</i>SHMT active site cavity and the mechanism of the external aldimine formation.</b> </figcaption> <div class="c-article-section__figure-content"> <div class="c-article-section__figure-item"> <a class="c-article-section__figure-link" data-test="img-link" data-track="click" data-track-label="image" data-track-action="view figure" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9/figures/5?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" rel="nofollow"> <picture> <source type="image/webp" srcset="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://media.springernature.com/lw685/springer-static/image/art%253A10.1038%252Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig5_HTML.png?as%3Dwebp"> <img aria-describedby="Fig5" src="//media.springernature.com/lw685/springer-static/image/art%3A10.1038%2Fs42004-023-00964-9/MediaObjects/42004_2023_964_Fig5_HTML.png" alt="figure 5" loading="lazy" width="685" height="690"> </picture></a> </div> <div class="c-article-section__figure-description" data-test="bottom-caption" id="figure-5-desc"> <p><b>a</b> Overview of substrate tracking into the active site of <i>Tth</i>SHMT revealed by X-ray and joint X-ray/neutron crystallography. The composite image was made by superimposing the <i>Tth</i>SHMT/L-Ser (RMS = 0.081) neutron structures and the TthSHMT/D-Ser (RMSD = 0.122) room-temperature X-ray structure with the substrate-free <i>Tth</i>SHMT. <b>b</b> Proposed mechanism for the generation of the external aldimine based on the current joint X-ray/neutron structures. Glu53 in TthSHMT is proposed to act as the general base to abstract the β-hydroxyl of L-Ser to subsequently form formaldehyde.</p> </div> </div> <div class="u-text-right u-hide-print"> <a class="c-article__pill-button" data-test="article-link" data-track="click" data-track-label="button" data-track-action="view figure" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9/figures/5?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" data-track-dest="link:Figure5 Full size image" aria-label="Full size image figure 5" rel="nofollow"><span>Full size image</span> <svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"> <use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-chevron-right-small" /> </svg></a> </div> </figure> </div> <p>In the internal aldimine state, when the SHMT active site is substrate-free or L-Ser has not yet reached the cationic substrate binding site to react with the Schiff base, the PLP N<sub>SB</sub> atom is not protonated whereas the pyridine N1 is protonated. Identical protonation states for PLP in the internal aldimine state have been observed in the joint XN structure of AAT<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 44" title="Dajnowicz, S. et al. Direct visualization of critical hydrogen atoms in a pyridoxal 5’-phosphate enzyme. Nat. Commun. 8, 955 (2017)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR44" id="ref-link-section-d2316419e1738">44</a></sup>. In disagreement with our experimental results, however, several published theoretical calculations of the SHMT catalytic mechanism used protonated, positively charged, N<sub>SB</sub> in the internal aldimine state<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 60" title="Fernandes, H. S., Ramos, M. J. & Cerqueira, N. M. F. S. A. Catalytic mechanism of the serine hydroxymethyltransferase: a computational ONIOM QM/MM study. ACS Catal. 8, 10096–10110 (2018)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR60" id="ref-link-section-d2316419e1744">60</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 83" title="Chiba, Y. et al. Mechanism for folate-independent aldolase reaction catalyzed by serine hydroxymethyltransferase. FEBS J. 279, 504–514 (2012)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR83" id="ref-link-section-d2316419e1747">83</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 84" title="Soniya, K. & Chandra, A. Free energy landscape and proton transfer pathways of the transimination reaction at the active site of the serine hydroxymethyltransferase enzyme in aqueous medium. J. Phys. Chem. B 125, 11848–11856 (2021)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR84" id="ref-link-section-d2316419e1750">84</a></sup>. In order to proceed through the transaldimination reaction, the incoming amino acid substrate needs to be deprotonated. We believe that N<sub>SB</sub> receives the proton from the α-amino group of the zwitterionic amino acid substrate just before or in concert with its attack on the PLP C4´ (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig5">5b</a>). Although the anionic α-amino group of L-Ser (<sup>−</sup>NH-Cα-COO<sup>−</sup>) was previously suggested as the true substrate<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 85" title="Di Salvo, M. L. et al. Structure-based mechanism for early PLP-mediated steps of rabbit cytosolic serine hydroxymethyltransferase reaction. Biomed. Res. Int. 2013, 458571 (2013)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR85" id="ref-link-section-d2316419e1764">85</a></sup>, our joint XN structures are not in favor of this scenario because the only nearby residue, His200, capable of accepting an H atom from the substrate is protonated on Nε2 that would face the α-amino group.</p> <p>According to the retro-aldol catalytic mechanism of SHMT catalysis, a general base should abstract a proton from the β-hydroxyl of L-Ser when it becomes part of the external aldimine. The previously proposed candidates for this role are Glu53, His122, His125, and His200<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 53" title="Renwick, S. B., Snell, K. & Baumann, U. The crystal structure of human cytosolic serine hydroxymethyltransferase: a target for cancer chemotherapy. Structure 6, 1105–1116 (1998)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR53" id="ref-link-section-d2316419e1771">53</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 66" title="Scarsdale, J. N., Radaev, S., Kazanina, G., Schirch, V. & Wright, H. T. Crystal structure at 2.4 Å resolution of E. coli serine hydroxymethyltransferase in complex with glycine substrate and 5-formyl tetrahydrofolate11Edited by I. A. Wilson. J. Mol. Biol. 296, 155–168 (2000)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR66" id="ref-link-section-d2316419e1774">66</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 86" title="Talwar, R., Jagath, J. R., Rao, N. A. & Savithri, H. S. His230 of serine hydroxymethyltransferase facilitates the proton abstraction step in catalysis. Eur. J. Biochem. 267, 1441–1446 (2000)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR86" id="ref-link-section-d2316419e1777">86</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 87" title="Rao, J. V. K., Prakash, V., Rao, N. A. & Savithri, H. S. The role of Glu74 and Tyr82 in the reaction catalyzed by sheep liver cytosolic serine hydroxymethyltransferase. Eur. J. Biochem 267, 5967–5976 (2000)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR87" id="ref-link-section-d2316419e1780">87</a></sup>. Analysis of our joint XN structures reveals that for the THF-dependent catalysis, the best candidate for the general base is Glu53 which is found in the deprotonated, carboxylate, form with an apparently low pK<sub>a</sub>. We believe that Glu53 would also act as the general base in the THF-independent reaction converting β-hydroxyamino acids to the corresponding aldehydes and Gly. Conversely, none of the three histidine residues, although neutral, can act as a general base because they are locked in H-bonds that would preclude their protonation, making them non-titratable residues at physiological pH. Specifically, His122, π-π stacked against the PLP pyridine ring, participates in H-bonds with Thr124 and its own main chain amide NH using Nδ1, whereas Nε2-H is directed towards the substrate. His125 donates Nε2-H in an H-bond with Asp197 and Nδ1 makes an H-bond with the main chain amide NH of His122. Moreover, His125 is >9 Å away from the cationic substrate binding site, too far to participate in the reaction. His200 also cannot be considered a possible catalytic base. It is part of the H-bond network that links O3´ to the His312 main chain. His200 Nε2-H faces the substrate, as mentioned above, and its Nδ1 is in an H-bond with His312 Nε2-H. Consequently, none of these histidine residues can be protonated during the SHMT catalysis. Moreover, they remained neutral even at the acidic pH of 5.5 used to grow <i>Tth</i>SHMT crystals. Our results thus indicate that Glu53 plays the general base role to deprotonate β-hydroxyl of L-Ser (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#Fig5">5b</a>), in agreement with the recent QM/MM studies which concluded that the retro-aldol mechanism is most probable for SHMT<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 60" title="Fernandes, H. S., Ramos, M. J. & Cerqueira, N. M. F. S. A. Catalytic mechanism of the serine hydroxymethyltransferase: a computational ONIOM QM/MM study. ACS Catal. 8, 10096–10110 (2018)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR60" id="ref-link-section-d2316419e1792">60</a></sup>.</p> <p>In conclusion, neutron crystallography at near-physiological (room) temperature was used to obtain all-atom structures of <i>Tth</i>SHMT where positions of H and D atoms were accurately located revealing protonation states of key residues and, as a result, mapping electrostatics in the enzyme active site. We observed protonated (positively charged) pyridine N1, deprotonated (negatively charged) phenolic O3′, and non-protonated (neutral) Schiff base N<sub>SB</sub> atoms within the PLP cofactor. Interestingly, all active site His residues were found in the monoprotonated (neutral) state, participating in H-bonding networks that would prevent their protonation at physiological pH. Based on the observed protonation states in the active site, Glu53 is proposed as the best candidate for the general base catalyst to orchestrate the retro-aldol transformation of L-Ser into Gly. The pathway of the substrate amino acid serine entering the active site cavity was tracked revealing a peripheral binding site, where the amino acid exists in the zwitterionic state, and the cationic binding site, where the substrate’s α-amino group is poised for the nucleophilic attack on Schiff base C4´ atom. Understanding the next stages in the SHMT catalysis will require mapping the H atom movements in the external aldimine with bound L-Ser and in complexes with THF or its analogs.</p> </div> </div> </section> <section data-title="Materials and methods"> <div class="c-article-section" id="Sec8-section"> <h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Sec8">Materials and methods</h2> <div class="c-article-section__content" id="Sec8-content"> <h3 class="c-article__sub-heading" id="Sec9">General information</h3> <p>Columns for protein purification were purchased from Cytiva (Piscataway, New Jersey, USA). His-tagged Tobacco Etch Virus (TEV) protease was produced in-house. Crystallization reagents and supplies were purchased from Hampton Research (Aliso Viejo, California, USA). Crystallographic supplies for crystal mounting and X-ray and neutron diffraction data collection at room temperature were purchased from MiTeGen (Ithaca, New York, USA) and Vitrocom (Mountain Lakes, New Jersey, USA). Deuterated L-Ser and hydrogenous D-Ser were purchased from Millipore Sigma (St. Louis, Montana, USA).</p> <h3 class="c-article__sub-heading c-article__sub-heading--divider" id="Sec10"><i>Tth</i>SHMT expression and purification</h3> <p>The <i>glyA</i> gene (Fig. <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S9</a>) encoding SHMT enzyme from the bacterium <i>Thermus thermophilus</i> was codon optimized, synthesized, and cloned into kanamycin-resistance plasmid, pJ411 (ATUM, Newark, CA), in addition to a DNA sequence encoding for an N-terminal polyhistidine-(His<sub>6</sub>)-tag with a 34 amino acid long linker. A TEV protease cleavage tag, ENLYFQS, was introduced at the <i>Tth</i>SHMT N-terminus sequence so that after cleavage the enzyme sequence started from Ser3 (Fig. <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S9</a>). This was done because residues Met1 and Val2 are not visible in the electron density maps in the previously deposited <i>Tth</i>SHMT structure (PDB ID 2DKJ). The plasmid was transformed into BL21(DE3) competent <i>E.coli</i> cells for expression. Transformed cells were grown in Luria-Bertani (LB) media supplemented with 50 μg/mL kanamycin antibiotic at 37 °C to an optical density of 0.8–1.0 and induced overnight with 1 mM isopropyl ß-D-1-thiogalactopyranoside (IPTG) at 22 °C (approximately 16–18 h). Induced cells were harvested by centrifugation at 5660 rpm at 4 °C, producing typical yields of 10 g of cells per 1 L of cell culture. A buffer containing 50 mM sodium phosphate pH 7.5, 500 mM NaCl, and 10 mM imidazole was used to resuspend the cell pellet, utilizing 5 mL of lysis buffer per gram of wet cell paste. The cells were stirred on ice for 30 minutes prior to mechanical sonication. The cell lysate was clarified by centrifugation at 17,000 rpm (~30,000 <i>g</i>) for 30 min. The supernatant was loaded onto a 5 mL HisTrap FF nickel column equilibrated with 20 mM HEPES pH 7.5, 100 mM NaCl, and 10 mM imidazole and washed with 5 column volumes (CV) of 20 mM HEPES pH 7.5, 100 mM NaCl, and 20 mM imidazole. The pure, tagged protein was eluted with 20 mM HEPES pH 7.5, 100 mM NaCl, and 500 mM imidazole in a linear gradient at relatively low imidazole concentrations (~50–60 mM). SHMT-containing fractions were pooled, and TEV protease was added to cleave the poly-histidine tag (1 mg TEV protease/100 mg of tagged protein). After room temperature overnight dialysis against 20 mM HEPES pH 7.5, 100 mM NaCl, and 1 mM EDTA, the TEV protease-treated fractions were loaded onto the 5 mL HisTrap FF nickel column and eluted in the flow-through. Pure <i>Tth</i>SHMT, verified by SDS-PAGE, was then dialyzed overnight against 40 mM NaOAc pH 5.4 and 1 mM PLP at 4 °C, concentrated to 19 mg/mL, and stored at −30 °C in the presence of 20% (v/v) glycerol.</p> <h3 class="c-article__sub-heading c-article__sub-heading--divider" id="Sec11">hSHMT2 expression and purification</h3> <p>The <i>SHMT2</i> gene encoding the SHMT enzyme from human mitochondrion (residues 37-504, Uniprot ID P34897, Fig. <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S10</a>) with mitochondrial leader sequence deleted was codon optimized, synthesized, and cloned into kanamycin-resistance plasmid, pJ411 (ATUM, Newark, CA). The DNA sequence encoding for a 35 amino acid long linking sequence containing an N-terminal His<sub>6</sub>-tag and the TEV protease cleavage tag so that after cleavage the enzyme sequence starts with Gly37 (Fig. <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S10</a>). The plasmid was transformed into BL21(DE3) competent <i>E. coli</i> cells for expression and grown in LB media supplemented with 50 μg/mL kanamycin antibiotic at 37 °C. The culture was grown to an optical density of 0.8–1.0 and induced overnight with 1 mM IPTG at 22 °C (approximately 16–18 h). Induced cells were harvested by centrifugation at 5660 rpm at 4 °C. Using 5 mL of lysis buffer per gram of wet cell paste, the cell pellet was resuspended in a buffer containing 20 mM HEPES pH 7.5, 500 mM NaCl, and 10 mM imidazole. Lysozyme was added at 0.1 mg/mL as the cells were stirred on ice for 30 min and then subsequently mechanically sonicated. The lysates were clarified by centrifugation at 30,000 <i>g</i> for 30 min and then loaded onto a 5 mL HisTrap FF nickel column equilibrated with 20 mM HEPES pH 7.5, 500 mM NaCl, and 10 mM imidazole. The column was washed with 20 mM HEPES pH 7.5, 500 mM NaCl, and 20 mM imidazole, and tagged hSHMT2 was eluted with a linear gradient of 20 mM HEPES pH 7.5, 500 mM NaCl, and 500 mM imidazole. TEV protease was added to the pooled hSHMT2-containing fractions in order to cleave the poly-histidine tag (1 mg TEV protease/100 mg of tagged protein). The sample was dialyzed overnight at room-temperature against 20 mM HEPES pH 7.5, 250 mM NaCl, and 1 mM EDTA. The TEV protease-treated fractions were loaded onto a 5 mL HisTrap FF nickel column and eluted in the flow-through. Pure hSHMT2, verified by SDS-PAGE, was then dialyzed overnight against 20 mM HEPES pH 7.5, 300 mM NaCl, and 1 mM PLP at 4 °C and concentrated to 18 mg/mL for crystallization setups. hSHMT2 was crystallized in 50 mM Tricine pH 8.2–8.4 and 11-13% PEG 3350 in sitting drop vapor diffusion experiments.</p> <h3 class="c-article__sub-heading c-article__sub-heading--divider" id="Sec12">Crystallization and H/D-exchange</h3> <p>Aliquots of pure <i>Tth</i>SHMT were thawed and dialyzed against 40 mM NaOAc pH 5.4 and 1 mM PLP to remove the glycerol. <i>Tth</i>SHMT (19 mg/mL) was crystallized in 40 mM NaOAc pH 5.5, 1 M (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>, and 0.5 M Li<sub>2</sub>SO<sub>4</sub> in sitting drop vapor diffusion experiments, producing showers of crystals and some crystal aggregates. Several crystal aggregates were crushed in their crystallization drops to create microcrystals for microseeding experiments. Large, single crystals for neutron diffraction were grown using a streak seeding method in 9-well glass plates and sandwich box setups. Specifically, after large crystallization drops were set up, a seeding tool from Hampton Research was dipped into the crushed crystals and then dipped quickly into the new crystal drops to transfer microcrystals. In this approach, only a few, but larger, crystals per drop of <i>Tth</i>SHMT grow. A crystal of ~2 mm<sup>3</sup> in volume suitable for neutron diffraction was mounted in a 2 mm-inner diameter quartz capillary with a liquid plug of 40 mM NaOAc pH 5.5, 1.0 M (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>, and 0.5 M Li<sub>2</sub>SO<sub>4</sub> prepared in 100% D<sub>2</sub>O to perform H/D-vapor exchange. The same crystal was used for both neutron crystallographic experiments, in the absence and presence of substrate L-Ser-d<sub>7</sub>. To prepare the crystal for soaking with L-Ser, the quartz capillary was unsealed, and the H/D-exchange liquid plug was removed. The capillary was then filled with 500 mM deuterated L-Ser, 40 mM NaOAc pH 5.5, 1.0 M (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>, and 0.5 Li<sub>2</sub>SO<sub>4</sub> left to soak overnight. The following day, the soaking solution was removed and replaced with a liquid plug of 40 mM NaOAc pH 5.5, 1.0 M (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>, and 0.5 Li<sub>2</sub>SO<sub>4</sub> in 100% D<sub>2</sub>O to perform H/D-vapor exchange. TthSHMT crystals for D-Ser soaking experiments were first transferred to a fresh drop containing 0.1 M NaOAc pH 5.5 and 15% PEG 4000, to remove excess sulfate, then moved to a drop containing 0.5 M D-Ser in 0.1 M NaOAc pH 5.5 and 15% PEG 4000. hSHMT2 at 18 mg/mL was crystallized in 50 mM Tricine pH 8.2–8.4 and 11–13% PEG 3350 in sitting drop vapor diffusion experiments producing hexagonal, rod-shaped crystals.</p> <h3 class="c-article__sub-heading c-article__sub-heading--divider" id="Sec13">Neutron diffraction data collection</h3> <p>Neutron diffraction was tested at room temperature and a preliminary dataset was obtained on the LADI-DALI beamline<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 88" title="Blakeley, M. P. et al. Neutron macromolecular crystallography with LADI-III. Acta Crystallogr. D. Biol. Crystallogr. 66, 1198–1205 (2010)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR88" id="ref-link-section-d2316419e1963">88</a></sup> at the Institut Laue-Langevin (ILL) in Grenoble. A complete room-temperature neutron diffraction dataset for the <i>Tth</i>SHMT internal aldimine was collected on the IMAGINE<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Meilleur, F. et al. The IMAGINE instrument: first neutron protein structure and new capabilities for neutron macromolecular crystallography. Acta Crystallogr. D. Biol. Crystallogr. 69, 2157–2160 (2013)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR89" id="ref-link-section-d2316419e1970">89</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Meilleur, F., Coates, L., Cuneo, M. J., Kovalevsky, A. & Myles, D. A. A. The neutron macromolecular crystallography instruments at oak ridge national laboratory: advances, challenges, and opportunities. Crystals 8, 388 (2018)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR90" id="ref-link-section-d2316419e1970_1">90</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Schroder, G. C., O’Dell, W. B., Myles, D. A. A., Kovalevsky, A. & Meilleur, F. IMAGINE: neutrons reveal enzyme chemistry. Acta Crystallogr. D. Struct. Biol. 74, 778–786 (2018)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR91" id="ref-link-section-d2316419e1970_2">91</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 92" title="Meilleur, F., Kovalevsky, A. & Myles, D. A. A. IMAGINE: The neutron protein crystallography beamline at the high flux isotope reactor. Methods Enzymol. 634, 69–85 (2020)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR92" id="ref-link-section-d2316419e1973">92</a></sup> single-crystal diffractometer at the HFIR at ORNL using a neutron wavelength range of 2.8–4.5 Å. Each neutron image was composed of a 20 h exposure of the crystal held in a stationary position. The crystal was rotated along the vertical axis (Δφ = 8°) before collecting each successive image. The crystal orientation was changed three times by tilting the capillary with respect to the incident neutron beam to improve data completeness. In total, 44 neutron diffraction images were collected. Neutron diffraction data processing was performed with a version of LAUEGEN<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 93" title="Campbell, J. W. Lauegen, an X-windows-based program for the processing of Laue X-Ray-diffraction data. J. Appl. Crystallogr. 28, 228–236 (1995)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR93" id="ref-link-section-d2316419e1977">93</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 94" title="Campbell, J. W., Hao, Q., Harding, M. M., Nguti, N. D. & Wilkinson, C. LAUEGEN version 6.0 and INTLDM. J. Appl. Crystallogr. 31, 496–502 (1998)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR94" id="ref-link-section-d2316419e1980">94</a></sup> modified to account for the geometry of the cylindrical image plate detector. The wavelength-normalization curve was determined using the intensities of symmetry-equivalent reflections at different wavelengths in LSCALE<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 95" title="Arzt, S., Campbell, J. W., Harding, M. M., Hao, Q. & Helliwell, J. R. LSCALE - the new normalization, scaling and absorption correction program in the Daresbury Laue software suite. J. Appl. Crystallogr. 32, 554–562 (1999)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR95" id="ref-link-section-d2316419e1984">95</a></sup>. No explicit absorption corrections were applied. The data were scaled and merged in SCALA (Weiss 2001).</p> <p>Room-temperature neutron diffraction data for the <i>Tth</i>SHMT-L-Ser pre-Michaelis complex were collected on the instrument MaNDi<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 96" title="Coates, L. et al. The macromolecular neutron diffractometer MaNDi at the spallation neutron source. J. Appl. Crystallogr. 48, 1302–1306 (2015)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR96" id="ref-link-section-d2316419e1994">96</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 97" title="Coates, L. & Sullivan, B. The macromolecular neutron diffractometer at the spallation neutron source. Method Enzymol. 634, 87–99 (2020)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR97" id="ref-link-section-d2316419e1997">97</a></sup> at the Spallation Neutron Source (SNS) at ORNL. The crystal was held stationary for 20 h exposures and rotated 10° around the φ-axis before collecting the next image. All neutrons between 2 and 4.16 Å were used to collect the frames, with a total of 25 images collected. Neutron diffraction data collection on MaNDi was processed and integrated with 3D time-of-flight profile fitting in Mantid<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 98" title="Arnold, O. et al. Mantid—Data analysis and visualization package for neutron scattering and μ SR experiments. Nucl. Instrum. Methods Phys. Res. Sect. A: Accel. Spectrom. Detect. Assoc. Equip. 764, 156–166 (2014)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR98" id="ref-link-section-d2316419e2001">98</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 99" title="Sullivan, B. et al. Improving the accuracy and resolution of neutron crystallographic data by three-dimensional profile fitting of Bragg peaks in reciprocal space. Acta Crystallogr. Sect. D.-Struct. Biol. 74, 1085–1095 (2018)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR99" id="ref-link-section-d2316419e2004">99</a></sup>. Wavelength normalization of the data was performed with LAUENORM<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 94" title="Campbell, J. W., Hao, Q., Harding, M. M., Nguti, N. D. & Wilkinson, C. LAUEGEN version 6.0 and INTLDM. J. Appl. Crystallogr. 31, 496–502 (1998)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR94" id="ref-link-section-d2316419e2008">94</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 100" title="Helliwell, J. R. et al. The recording and analysis of synchrotron X-radiation laue diffraction photographs. J. Appl. Crystallogr. 22, 483–497 (1989)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR100" id="ref-link-section-d2316419e2011">100</a></sup> and the data were scaled and merged in SCALA<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 101" title="Weiss, M. S. Global indicators of X-ray data quality. J. Appl. Crystallogr. 34, 130–135 (2001)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR101" id="ref-link-section-d2316419e2015">101</a></sup>. Neutron data collection statistics for both datasets are shown in Table <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S1</a>.</p> <h3 class="c-article__sub-heading c-article__sub-heading--divider" id="Sec14">Room-temperature X-ray diffraction data collection and structure refinement</h3> <p>Room temperature X-ray diffraction data collection for <i>Tth</i>SHMT crystals was carried out on a Rigaku HighFlux HomeLab instrument equipped with a MicroMax-007 HF X-ray generator, Osmic VariMax optics, and a DECTRIS Eiger R 4 M detector at Oak Ridge National Laboratory. The data were indexed and integrated using the CrysAlis Pro software (Rigaku, The Woodlands, TX), then reduced and scaled with the AIMLESS program in the CCP4 software suite<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 102" title="Evans, P. R. & Murshudov, G. N. How good are my data and what is the resolution? Acta Crystallogr. D. Biol. Crystallogr. 69, 1204–1214 (2013)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR102" id="ref-link-section-d2316419e2034">102</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 103" title="Winn, M. D. et al. Overview of the CCP4 suite and current developments. Acta Crystallogr. Sect. D.-Struct. Biol. 67, 235–242 (2011)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR103" id="ref-link-section-d2316419e2037">103</a></sup>. The <i>Tth</i>SHMT room-temperature X-ray structures were solved by molecular replacement in PHASER<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 104" title="Mccoy, A. J. et al. Phaser crystallographic software. J. Appl. Crystallogr. 40, 658–674 (2007)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR104" id="ref-link-section-d2316419e2044">104</a></sup> using phases from PDB code 2DKJ. Room temperature X-ray diffraction data collection for hSHMT2 crystals was performed from a single crystal on the ID19 beamline at SBC-CAT using a Pilatus3 × 6 M detector at the Advanced Photon Source (APS). X-ray diffraction data were integrated and scaled using the HKL3000 software suite<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 105" title="Minor, W., Cymborowski, M., Otwinowski, Z. & Chruszcz, M. HKL-3000: the integration of data reduction and structure solution-from diffraction images to an initial model in minutes. Acta Crystallogr. D. Biol. Crystallogr. 62, 859–866 (2006)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR105" id="ref-link-section-d2316419e2048">105</a></sup>. To minimize radiation damage to the hSHMT2 crystal, the X-ray beam intensity was attenuated 40 times and the data were collected with 0.2 sec/frame rate. The radiation damage to the crystal was estimated by the HKL3000 software to be less than 5%. The hSHMT2 structure was solved by molecular replacement using PHASER<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 104" title="Mccoy, A. J. et al. Phaser crystallographic software. J. Appl. Crystallogr. 40, 658–674 (2007)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR104" id="ref-link-section-d2316419e2053">104</a></sup>. The cryo-temperature X-ray structure of hSHMT2 (PDB ID 4PVF)<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 18" title="Giardina, G. et al. How pyridoxal 5’-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state. FEBS J. 282, 1225–1241 (2015)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR18" id="ref-link-section-d2316419e2057">18</a></sup> was used as a starting model. All the structures were subsequently refined against the room temperature data with Phenix.refine from the PHENIX suite<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 106" title="Adams, P. D. et al. PHENIX: a comprehensive Python-based system for macromolecular structure solution. Acta Crystallogr. D. Biol. Crystallogr. 66, 213–221 (2010)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR106" id="ref-link-section-d2316419e2061">106</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 107" title="Liebschner, D. et al. Macromolecular structure determination using X-rays, neutrons and electrons: recent developments in Phenix. Acta Crystallogr. Sect. D.-Struct. Biol. 75, 861–877 (2019)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR107" id="ref-link-section-d2316419e2064">107</a></sup> and COOT<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Emsley, P. & Cowtan, K. Coot: model-building tools for molecular graphics. Acta Crystallogr. Sect. D.-Struct. Biol. 60, 2126–2132 (2004)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR108" id="ref-link-section-d2316419e2068">108</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Emsley, P., Lohkamp, B., Scott, W. G. & Cowtan, K. Features and development of Coot. Acta Crystallogr D. Biol. Crystallogr 66, 486–501 (2010)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR109" id="ref-link-section-d2316419e2068_1">109</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 110" title="Casanal, A., Lohkamp, B. & Emsley, P. Current developments in Coot for macromolecular model building of Electron Cryo-microscopy and Crystallographic Data. Protein Sci. 29, 1069–1078 (2020)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR110" id="ref-link-section-d2316419e2071">110</a></sup>. Geometry validation was aided by Molprobity<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 111" title="Chen, V. B. et al. MolProbity: all-atom structure validation for macromolecular crystallography. Acta Crystallogr D. Biol. Crystallogr 66, 12–21 (2010)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR111" id="ref-link-section-d2316419e2075">111</a></sup>. All ligand restraints were generated with eLBOW<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 112" title="Moriarty, N. W., Grosse-Kunstleve, R. W. & Adams, P. D. Electronic ligand builder and optimization workbench (eLBOW): a tool for ligand coordinate and restraint generation. Acta Crystallogr D. Biol. Crystallogr 65, 1074–1080 (2009)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR112" id="ref-link-section-d2316419e2079">112</a></sup> using geometry optimized by quantum mechanical calculations in Gaussian 16<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 113" title="Gaussian 16 Rev. A.03 (Gaussian Inc., Wallingford, CT, 2016)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR113" id="ref-link-section-d2316419e2084">113</a></sup> at B3LYP/6-31 g(d,p) level of theory. Final data collection and refinement statistics can be found in Table <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S2</a>.</p> <h4 class="c-article__sub-heading c-article__sub-heading--small" id="Sec15">Joint XN refinement</h4> <p>Joint XN-refinement of the <i>Tth</i>SHMT internal aldimine structure and <i>Tth</i>SHMT pre-Michaelis complex were performed using the nCNS<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 114" title="Mustyakimov, M. & Langan, P. nCNS: an open source distribution patch for CNS for macromolecular structure refinement. Ver. 1.0.8. (Los Alamos National Laboratory, Los Alamos, NM, 2007)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR114" id="ref-link-section-d2316419e2104">114</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 115" title="Adams, P. D., Mustyakimov, M., Afonine, P. V. & Langan, P. Generalized X-ray and neutron crystallographic analysis: more accurate and complete structures for biological macromolecules. Acta Crystallogr. D. Biol. Crystallogr. 65, 567–573 (2009)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR115" id="ref-link-section-d2316419e2107">115</a></sup> patch of the Crystallography & NMR Systems (CNS)<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 115" title="Adams, P. D., Mustyakimov, M., Afonine, P. V. & Langan, P. Generalized X-ray and neutron crystallographic analysis: more accurate and complete structures for biological macromolecules. Acta Crystallogr. D. Biol. Crystallogr. 65, 567–573 (2009)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR115" id="ref-link-section-d2316419e2111">115</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 116" title="Brunger, A. T. et al. Crystallography & NMR system: a new software suite for macromolecular structure determination. Acta Crystallogr. D. 54, 905–921 (1998)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR116" id="ref-link-section-d2316419e2114">116</a></sup> software suite for macromolecular structure determination. The refinement procedure began with a single rigid body refinement followed by a series of atomic position, atomic displacement parameters, and D atom occupancy refinements. The structures were visualized in the graphics program COOT<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Emsley, P. & Cowtan, K. Coot: model-building tools for molecular graphics. Acta Crystallogr. Sect. D.-Struct. Biol. 60, 2126–2132 (2004)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR108" id="ref-link-section-d2316419e2118">108</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Emsley, P., Lohkamp, B., Scott, W. G. & Cowtan, K. Features and development of Coot. Acta Crystallogr D. Biol. Crystallogr 66, 486–501 (2010)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR109" id="ref-link-section-d2316419e2118_1">109</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 110" title="Casanal, A., Lohkamp, B. & Emsley, P. Current developments in Coot for macromolecular model building of Electron Cryo-microscopy and Crystallographic Data. Protein Sci. 29, 1069–1078 (2020)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR110" id="ref-link-section-d2316419e2121">110</a></sup>, in between rounds of refinements to inspect side chain modeling and correctly rotate side chain hydroxyl, thiol, and ammonium groups, as well as rotate water molecules to make appropriate H-bonding networks based on both 2F<sub>O</sub>−F<sub>C</sub> and F<sub>O</sub>−F<sub>C</sub> nuclear scattering length density maps. All water molecules in the model are assumed to be and refined as D<sub>2</sub>O as a consequence of the H/D-vapor exchange. Because hydrogenous protein was used in this experiment, the protein was modeled with H atoms at non-exchangeable positions, that is in C-H bonds. All labile, thus exchangeable, H positions in the structure were initially modeled as D until their occupancies were refined. An individual occupancy of −0.56 is associated with the presence of pure H at that position, whereas occupancy of 1.00 is indicative of pure D, because the neutron scattering length of H is −0.56 times that of D. Before depositing the neutron structures to the PDB, coordinates of each D atom were split into two records corresponding to an H and a D partially occupying the same site, both with positive partial occupancies that add up to unity. The percent D at a specific site is calculated according to the following formula: % D = (occupancy(D) + 0.56)/1.56. Neutron refinement statistics can be found in Table <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S1</a>.</p> <h3 class="c-article__sub-heading c-article__sub-heading--divider" id="Sec16">Quantum chemical calculations</h3> <p>The 2D relaxed potential energy profiles of the C4′-N<sub>SB</sub> bond rotation around the PLP pyridine ring were calculated with a simplified model of the internal aldimine (Figure <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM2">S7</a>). The model was truncated at Cβ of the lysine-portion of the internal aldimine and the phosphate group was removed, making C5′ a methyl group. The scans were completed at B3PW91/Def2-TZVPP level of theory<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 117" title="Weigend, F. & Ahlrichs, R. Balanced basis sets of split valence, triple zeta valence and quadruple zeta valence quality for H to Rn: design and assessment of accuracy. Phys. Chem. Chem. Phys. 7, 3297–3305 (2005)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR117" id="ref-link-section-d2316419e2153">117</a>,<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 118" title="Weigend, F. Accurate Coulomb-fitting basis sets for H to Rn. Phys. Chem. Chem. Phys. 8, 1057–1065 (2006)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR118" id="ref-link-section-d2316419e2156">118</a></sup> and reproduced the geometry observed in the experimental methods. Starting from the torsion angle observed in the <i>Tth</i>SHMT joint XN substrate-free internal aldimine structure, the full rotation of C3-C4- C4′-N<sub>SB</sub> was scanned. The scan was also performed on the model with a protonated N<sub>SB</sub>. All calculations were performed with Gaussian16<sup><a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 113" title="Gaussian 16 Rev. A.03 (Gaussian Inc., Wallingford, CT, 2016)." href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#ref-CR113" id="ref-link-section-d2316419e2168">113</a></sup>.</p> <h3 class="c-article__sub-heading c-article__sub-heading--divider" id="Sec17">Reporting summary</h3> <p>Further information on research design is available in the <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM8">Nature Portfolio Reporting Summary</a> linked to this article.</p> </div> </div> </section> </div> <div> <section data-title="Data availability"> <div class="c-article-section" id="data-availability-section"> <h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="data-availability">Data availability</h2> <div class="c-article-section__content" id="data-availability-content"> <p>The structures and corresponding structure factors have been deposited into the protein data bank with the PDB accession codes 8SUJ for <i>Tth</i>SHMT (Supplementary Data <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM4">1</a>), 8SSJ for hSHMT2 (Supplementary Data <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM5">2</a>) 8SUI for <i>Tth</i>SHMT/L-Ser (Supplementary Data <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM6">3</a>), and 8SSY for <i>Tth</i>SHMT/D-Ser (Supplementary Data <a data-track="click" data-track-label="link" data-track-action="supplementary material anchor" href="https://www-nature-com.translate.goog/articles/s42004-023-00964-9?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto#MOESM7">4</a>). Supporting information is available online.</p> </div> </div> </section> <div id="MagazineFulltextArticleBodySuffix"> <section aria-labelledby="Bib1" data-title="References"> <div class="c-article-section" id="Bib1-section"> <h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Bib1">References</h2> <div class="c-article-section__content" id="Bib1-content"> <div data-container-section="references"> <ol class="c-article-references" data-track-component="outbound reference" data-track-context="references section"> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="1."><p class="c-article-references__text" id="ref-CR1">Eliot, A. C. & Kirsch, J. F. Pyridoxal phosphate enzymes: mechanistic, structural, and evolutionary considerations. <i>Annu Rev. Biochem</i> <b>73</b>, 383–415 (2004).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1146/annurev.biochem.73.011303.074021" data-track-item_id="10.1146/annurev.biochem.73.011303.074021" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1146%252Fannurev.biochem.73.011303.074021" aria-label="Article reference 1" data-doi="10.1146/annurev.biochem.73.011303.074021">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD2cXmslags7Y%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 1">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D15189147" aria-label="PubMed reference 1">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 1" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DPyridoxal%2520phosphate%2520enzymes%253A%2520mechanistic%252C%2520structural%252C%2520and%2520evolutionary%2520considerations%26journal%3DAnnu%2520Rev.%2520Biochem%26doi%3D10.1146%252Fannurev.biochem.73.011303.074021%26volume%3D73%26pages%3D383-415%26publication_year%3D2004%26author%3DEliot%252CAC%26author%3DKirsch%252CJF"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="2."><p class="c-article-references__text" id="ref-CR2">Liang, J., Han, Q., Tan, Y., Ding, H. & Li, J. Current advances on structure-function relationships of pyridoxal 5’-phosphate-dependent enzymes. <i>Front Mol. Biosci.</i> <b>6</b>, 4 (2019).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.3389/fmolb.2019.00004" data-track-item_id="10.3389/fmolb.2019.00004" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.3389%252Ffmolb.2019.00004" aria-label="Article reference 2" data-doi="10.3389/fmolb.2019.00004">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC1MXhtlaksb%2FO?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 2">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D30891451" aria-label="PubMed reference 2">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6411801" aria-label="PubMed Central reference 2">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 2" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DCurrent%2520advances%2520on%2520structure-function%2520relationships%2520of%2520pyridoxal%25205%25E2%2580%2599-phosphate-dependent%2520enzymes%26journal%3DFront%2520Mol.%2520Biosci.%26doi%3D10.3389%252Ffmolb.2019.00004%26volume%3D6%26publication_year%3D2019%26author%3DLiang%252CJ%26author%3DHan%252CQ%26author%3DTan%252CY%26author%3DDing%252CH%26author%3DLi%252CJ"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="3."><p class="c-article-references__text" id="ref-CR3">Grishin, N. V., Phillips, M. A. & Goldsmith, E. J. Modeling of the Spatial Structure of Eukaryotic Ornithine Decarboxylases. <i>Protein Sci.</i> <b>4</b>, 1291–1304 (1995).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1002/pro.5560040705" data-track-item_id="10.1002/pro.5560040705" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1002%252Fpro.5560040705" aria-label="Article reference 3" data-doi="10.1002/pro.5560040705">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaK2MXms1Kgu7g%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 3">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D7670372" aria-label="PubMed reference 3">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2143167" aria-label="PubMed Central reference 3">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 3" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DModeling%2520of%2520the%2520Spatial%2520Structure%2520of%2520Eukaryotic%2520Ornithine%2520Decarboxylases%26journal%3DProtein%2520Sci.%26doi%3D10.1002%252Fpro.5560040705%26volume%3D4%26pages%3D1291-1304%26publication_year%3D1995%26author%3DGrishin%252CNV%26author%3DPhillips%252CMA%26author%3DGoldsmith%252CEJ"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="4."><p class="c-article-references__text" id="ref-CR4">Jansonius, J. N. Structure, evolution and action of vitamin B6-dependent enzymes. <i>Curr. Opin. Struct. Biol.</i> <b>8</b>, 759–769 (1998).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/S0959-440X(98)80096-1" data-track-item_id="10.1016/S0959-440X(98)80096-1" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252FS0959-440X%252898%252980096-1" aria-label="Article reference 4" data-doi="10.1016/S0959-440X(98)80096-1">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaK1MXhs1OqsQ%3D%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 4">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D9914259" aria-label="PubMed reference 4">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 4" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DStructure%252C%2520evolution%2520and%2520action%2520of%2520vitamin%2520B6-dependent%2520enzymes%26journal%3DCurr.%2520Opin.%2520Struct.%2520Biol.%26doi%3D10.1016%252FS0959-440X%252898%252980096-1%26volume%3D8%26pages%3D759-769%26publication_year%3D1998%26author%3DJansonius%252CJN"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="5."><p class="c-article-references__text" id="ref-CR5">Percudani, R. & Peracchi, A. A genomic overview of pyridoxal-phosphate-dependent enzymes. <i>EMBO Rep.</i> <b>4</b>, 850–854 (2003).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1038/sj.embor.embor914" data-track-item_id="10.1038/sj.embor.embor914" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1038%252Fsj.embor.embor914" aria-label="Article reference 5" data-doi="10.1038/sj.embor.embor914">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD3sXmvVWmurc%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 5">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D12949584" aria-label="PubMed reference 5">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1326353" aria-label="PubMed Central reference 5">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 5" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DA%2520genomic%2520overview%2520of%2520pyridoxal-phosphate-dependent%2520enzymes%26journal%3DEMBO%2520Rep.%26doi%3D10.1038%252Fsj.embor.embor914%26volume%3D4%26pages%3D850-854%26publication_year%3D2003%26author%3DPercudani%252CR%26author%3DPeracchi%252CA"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="6."><p class="c-article-references__text" id="ref-CR6">Amadasi, A. et al. Pyridoxal 5’-phosphate enzymes as targets for therapeutic agents. <i>Curr. Med Chem.</i> <b>14</b>, 1291–1324 (2007).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.2174/092986707780597899" data-track-item_id="10.2174/092986707780597899" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.2174%252F092986707780597899" aria-label="Article reference 6" data-doi="10.2174/092986707780597899">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD2sXkvFCntr0%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 6">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D17504214" aria-label="PubMed reference 6">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 6" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DPyridoxal%25205%25E2%2580%2599-phosphate%2520enzymes%2520as%2520targets%2520for%2520therapeutic%2520agents%26journal%3DCurr.%2520Med%2520Chem.%26doi%3D10.2174%252F092986707780597899%26volume%3D14%26pages%3D1291-1324%26publication_year%3D2007%26author%3DAmadasi%252CA"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="7."><p class="c-article-references__text" id="ref-CR7">Steffen-Munsberg, F. et al. Bioinformatic analysis of a PLP-dependent enzyme superfamily suitable for biocatalytic applications. <i>Biotechnol. Adv.</i> <b>33</b>, 566–604 (2015).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.biotechadv.2014.12.012" data-track-item_id="10.1016/j.biotechadv.2014.12.012" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fj.biotechadv.2014.12.012" aria-label="Article reference 7" data-doi="10.1016/j.biotechadv.2014.12.012">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC2MXjtVSlu7s%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 7">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D25575689" aria-label="PubMed reference 7">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 7" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DBioinformatic%2520analysis%2520of%2520a%2520PLP-dependent%2520enzyme%2520superfamily%2520suitable%2520for%2520biocatalytic%2520applications%26journal%3DBiotechnol.%2520Adv.%26doi%3D10.1016%252Fj.biotechadv.2014.12.012%26volume%3D33%26pages%3D566-604%26publication_year%3D2015%26author%3DSteffen-Munsberg%252CF"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="8."><p class="c-article-references__text" id="ref-CR8">Dunathan, H. C. Conformation and reaction specificity in pyridoxal phosphate enzymes. <i>Proc. Natl Acad. Sci. USA</i> <b>55</b>, 712 (1966).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1073/pnas.55.4.712" data-track-item_id="10.1073/pnas.55.4.712" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1073%252Fpnas.55.4.712" aria-label="Article reference 8" data-doi="10.1073/pnas.55.4.712">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaF28XktFems70%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 8">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D5219675" aria-label="PubMed reference 8">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC224217" aria-label="PubMed Central reference 8">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 8" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DConformation%2520and%2520reaction%2520specificity%2520in%2520pyridoxal%2520phosphate%2520enzymes%26journal%3DProc.%2520Natl%2520Acad.%2520Sci.%2520USA%26doi%3D10.1073%252Fpnas.55.4.712%26volume%3D55%26publication_year%3D1966%26author%3DDunathan%252CHC"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="9."><p class="c-article-references__text" id="ref-CR9">Richard, J. P., Amyes, T. L., Crugeiras, J. & Rios, A. Pyridoxal 5 ’-phosphate: electrophilic catalyst extraordinaire. <i>Curr. Opin. Chem. Biol.</i> <b>13</b>, 475–483 (2009).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.cbpa.2009.06.023" data-track-item_id="10.1016/j.cbpa.2009.06.023" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fj.cbpa.2009.06.023" aria-label="Article reference 9" data-doi="10.1016/j.cbpa.2009.06.023">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD1MXhtFKnsLvE?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 9">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D19640775" aria-label="PubMed reference 9">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 9" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DPyridoxal%25205%2520%25E2%2580%2599-phosphate%253A%2520electrophilic%2520catalyst%2520extraordinaire%26journal%3DCurr.%2520Opin.%2520Chem.%2520Biol.%26doi%3D10.1016%252Fj.cbpa.2009.06.023%26volume%3D13%26pages%3D475-483%26publication_year%3D2009%26author%3DRichard%252CJP%26author%3DAmyes%252CTL%26author%3DCrugeiras%252CJ%26author%3DRios%252CA"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="10."><p class="c-article-references__text" id="ref-CR10">Toney, M. D. Controlling reaction specificity in pyridoxal phosphate enzymes. <i>Biochim Biophys. Acta</i> <b>1814</b>, 1407–1418 (2011).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.bbapap.2011.05.019" data-track-item_id="10.1016/j.bbapap.2011.05.019" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fj.bbapap.2011.05.019" aria-label="Article reference 10" data-doi="10.1016/j.bbapap.2011.05.019">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC3MXhtlaqtb3K?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 10">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D21664990" aria-label="PubMed reference 10">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3359020" aria-label="PubMed Central reference 10">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 10" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DControlling%2520reaction%2520specificity%2520in%2520pyridoxal%2520phosphate%2520enzymes%26journal%3DBiochim%2520Biophys.%2520Acta%26doi%3D10.1016%252Fj.bbapap.2011.05.019%26volume%3D1814%26pages%3D1407-1418%26publication_year%3D2011%26author%3DToney%252CMD"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="11."><p class="c-article-references__text" id="ref-CR11">Schirch, L. Serine Hydroxymethyltransferase. <i>Adv. Enzymol. Ramb</i> <b>53</b>, 83–112 (1982).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaL38Xhtlynur8%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 11">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 11" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DSerine%2520Hydroxymethyltransferase%26journal%3DAdv.%2520Enzymol.%2520Ramb%26volume%3D53%26pages%3D83-112%26publication_year%3D1982%26author%3DSchirch%252CL"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="12."><p class="c-article-references__text" id="ref-CR12">Ulevitch, R. J. & Kallen, R. G. Studies of reactions of lamb liver serine hydroxymethylase with l-phenylalanine - kinetic isotope effects upon quinonoid intermediate formation. <i>Biochemistry</i> <b>16</b>, 5350–5354 (1977).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/bi00643a028" data-track-item_id="10.1021/bi00643a028" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Fbi00643a028" aria-label="Article reference 12" data-doi="10.1021/bi00643a028">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaE2sXlvFKgtr8%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 12">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D921937" aria-label="PubMed reference 12">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 12" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DStudies%2520of%2520reactions%2520of%2520lamb%2520liver%2520serine%2520hydroxymethylase%2520with%2520l-phenylalanine%2520-%2520kinetic%2520isotope%2520effects%2520upon%2520quinonoid%2520intermediate%2520formation%26journal%3DBiochemistry%26doi%3D10.1021%252Fbi00643a028%26volume%3D16%26pages%3D5350-5354%26publication_year%3D1977%26author%3DUlevitch%252CRJ%26author%3DKallen%252CRG"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="13."><p class="c-article-references__text" id="ref-CR13">Thomas, N. R., Schirch, V. & Gani, D. Synthesis of (2r)-[1-C-13]-2-Amino-2-Methylmalonic and (2s)-[1-C-13]-2-Amino-2-Methylmalonic Acid, Probes for the Serine Hydroxymethyltransferase Reaction - Stereospecific Decarboxylation of the 2-Pro-R Carboxy Group with the Retention of Configuration. <i>J. Chem. Soc. Chem. Comm.</i> 400–402, <a href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1039/c39900000400" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.1039/c39900000400">https://doi.org/10.1039/c39900000400</a> (1990).</p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="14."><p class="c-article-references__text" id="ref-CR14">Shostak, K. & Schirch, V. Serine hydroxymethyltransferase: mechanism of the racemization and transamination of D- and L-alanine. <i>Biochemistry</i> <b>27</b>, 8007–8014 (1988).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/bi00421a006" data-track-item_id="10.1021/bi00421a006" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Fbi00421a006" aria-label="Article reference 14" data-doi="10.1021/bi00421a006">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaL1cXls1Khu7c%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 14">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D3069126" aria-label="PubMed reference 14">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 14" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DSerine%2520hydroxymethyltransferase%253A%2520mechanism%2520of%2520the%2520racemization%2520and%2520transamination%2520of%2520D-%2520and%2520L-alanine%26journal%3DBiochemistry%26doi%3D10.1021%252Fbi00421a006%26volume%3D27%26pages%3D8007-8014%26publication_year%3D1988%26author%3DShostak%252CK%26author%3DSchirch%252CV"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="15."><p class="c-article-references__text" id="ref-CR15">Herbig, K. et al. Cytoplasmic serine hydroxymethyltransferase mediates competition between folate-dependent deoxyribonucleotide and S-adenosylmethionine biosyntheses. <i>J. Biol. Chem.</i> <b>277</b>, 38381–38389 (2002).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1074/jbc.M205000200" data-track-item_id="10.1074/jbc.M205000200" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1074%252Fjbc.M205000200" aria-label="Article reference 15" data-doi="10.1074/jbc.M205000200">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD38Xns1CnsLw%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 15">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D12161434" aria-label="PubMed reference 15">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 15" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DCytoplasmic%2520serine%2520hydroxymethyltransferase%2520mediates%2520competition%2520between%2520folate-dependent%2520deoxyribonucleotide%2520and%2520S-adenosylmethionine%2520biosyntheses%26journal%3DJ.%2520Biol.%2520Chem.%26doi%3D10.1074%252Fjbc.M205000200%26volume%3D277%26pages%3D38381-38389%26publication_year%3D2002%26author%3DHerbig%252CK"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="16."><p class="c-article-references__text" id="ref-CR16">Xie, M. & Pei, D. S. Serine hydroxymethyltransferase 2: a novel target for human cancer therapy. <i>Invest N. Drug</i> <b>39</b>, 1671–1681 (2021).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="noopener" data-track-label="10.1007/s10637-021-01144-z" data-track-item_id="10.1007/s10637-021-01144-z" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://link.springer.com/doi/10.1007/s10637-021-01144-z" aria-label="Article reference 16" data-doi="10.1007/s10637-021-01144-z">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXhs1CmtLnL?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 16">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 16" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DSerine%2520hydroxymethyltransferase%25202%253A%2520a%2520novel%2520target%2520for%2520human%2520cancer%2520therapy%26journal%3DInvest%2520N.%2520Drug%26doi%3D10.1007%252Fs10637-021-01144-z%26volume%3D39%26pages%3D1671-1681%26publication_year%3D2021%26author%3DXie%252CM%26author%3DPei%252CDS"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="17."><p class="c-article-references__text" id="ref-CR17">Florio, R., di Salvo, M. L., Vivoli, M. & Contestabile, R. Serine hydroxymethyltransferase: a model enzyme for mechanistic, structural, and evolutionary studies. <i>Biochim Biophys. Acta</i> <b>1814</b>, 1489–1496 (2011).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.bbapap.2010.10.010" data-track-item_id="10.1016/j.bbapap.2010.10.010" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fj.bbapap.2010.10.010" aria-label="Article reference 17" data-doi="10.1016/j.bbapap.2010.10.010">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC3MXhtlaqtbrJ?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 17">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D21059411" aria-label="PubMed reference 17">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 17" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DSerine%2520hydroxymethyltransferase%253A%2520a%2520model%2520enzyme%2520for%2520mechanistic%252C%2520structural%252C%2520and%2520evolutionary%2520studies%26journal%3DBiochim%2520Biophys.%2520Acta%26doi%3D10.1016%252Fj.bbapap.2010.10.010%26volume%3D1814%26pages%3D1489-1496%26publication_year%3D2011%26author%3DFlorio%252CR%26author%3DSalvo%252CML%26author%3DVivoli%252CM%26author%3DContestabile%252CR"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="18."><p class="c-article-references__text" id="ref-CR18">Giardina, G. et al. How pyridoxal 5’-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state. <i>FEBS J.</i> <b>282</b>, 1225–1241 (2015).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1111/febs.13211" data-track-item_id="10.1111/febs.13211" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1111%252Ffebs.13211" aria-label="Article reference 18" data-doi="10.1111/febs.13211">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC2MXlsFartrY%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 18">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D25619277" aria-label="PubMed reference 18">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 18" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DHow%2520pyridoxal%25205%25E2%2580%2599-phosphate%2520differentially%2520regulates%2520human%2520cytosolic%2520and%2520mitochondrial%2520serine%2520hydroxymethyltransferase%2520oligomeric%2520state%26journal%3DFEBS%2520J.%26doi%3D10.1111%252Ffebs.13211%26volume%3D282%26pages%3D1225-1241%26publication_year%3D2015%26author%3DGiardina%252CG"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="19."><p class="c-article-references__text" id="ref-CR19">Tramonti, A. et al. Human cytosolic and mitochondrial serine hydroxymethyltransferase isoforms in comparison: full kinetic characterization and substrate inhibition properties. <i>Biochemistry</i> <b>57</b>, 6984–6996 (2018).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/acs.biochem.8b01074" data-track-item_id="10.1021/acs.biochem.8b01074" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Facs.biochem.8b01074" aria-label="Article reference 19" data-doi="10.1021/acs.biochem.8b01074">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC1cXitlGqu7rE?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 19">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D30500180" aria-label="PubMed reference 19">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 19" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DHuman%2520cytosolic%2520and%2520mitochondrial%2520serine%2520hydroxymethyltransferase%2520isoforms%2520in%2520comparison%253A%2520full%2520kinetic%2520characterization%2520and%2520substrate%2520inhibition%2520properties%26journal%3DBiochemistry%26doi%3D10.1021%252Facs.biochem.8b01074%26volume%3D57%26pages%3D6984-6996%26publication_year%3D2018%26author%3DTramonti%252CA"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="20."><p class="c-article-references__text" id="ref-CR20">Garrow, T. A. et al. Cloning of human cdnas encoding mitochondrial and cytosolic serine hydroxymethyltransferases and chromosomal localization. <i>J. Biol. Chem.</i> <b>268</b>, 11910–11916 (1993).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/S0021-9258(19)50286-1" data-track-item_id="10.1016/S0021-9258(19)50286-1" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252FS0021-9258%252819%252950286-1" aria-label="Article reference 20" data-doi="10.1016/S0021-9258(19)50286-1">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaK3sXltlalt7w%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 20">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D8505317" aria-label="PubMed reference 20">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 20" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DCloning%2520of%2520human%2520cdnas%2520encoding%2520mitochondrial%2520and%2520cytosolic%2520serine%2520hydroxymethyltransferases%2520and%2520chromosomal%2520localization%26journal%3DJ.%2520Biol.%2520Chem.%26doi%3D10.1016%252FS0021-9258%252819%252950286-1%26volume%3D268%26pages%3D11910-11916%26publication_year%3D1993%26author%3DGarrow%252CTA"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="21."><p class="c-article-references__text" id="ref-CR21">Ducker, G. S. & Rabinowitz, J. D. One-carbon metabolism in health and disease. <i>Cell Metab.</i> <b>25</b>, 27–42 (2017).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.cmet.2016.08.009" data-track-item_id="10.1016/j.cmet.2016.08.009" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fj.cmet.2016.08.009" aria-label="Article reference 21" data-doi="10.1016/j.cmet.2016.08.009">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC28XhsFajsLbF?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 21">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D27641100" aria-label="PubMed reference 21">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 21" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DOne-carbon%2520metabolism%2520in%2520health%2520and%2520disease%26journal%3DCell%2520Metab.%26doi%3D10.1016%252Fj.cmet.2016.08.009%26volume%3D25%26pages%3D27-42%26publication_year%3D2017%26author%3DDucker%252CGS%26author%3DRabinowitz%252CJD"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="22."><p class="c-article-references__text" id="ref-CR22">Lee, G. Y. et al. Comparative oncogenomics identifies PSMB4 and SHMT2 as potential cancer driver genes. <i>Cancer Res</i> <b>74</b>, 3114–3126 (2014).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1158/0008-5472.CAN-13-2683" data-track-item_id="10.1158/0008-5472.CAN-13-2683" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1158%252F0008-5472.CAN-13-2683" aria-label="Article reference 22" data-doi="10.1158/0008-5472.CAN-13-2683">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC2cXovFaksb8%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 22">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D24755469" aria-label="PubMed reference 22">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 22" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DComparative%2520oncogenomics%2520identifies%2520PSMB4%2520and%2520SHMT2%2520as%2520potential%2520cancer%2520driver%2520genes%26journal%3DCancer%2520Res%26doi%3D10.1158%252F0008-5472.CAN-13-2683%26volume%3D74%26pages%3D3114-3126%26publication_year%3D2014%26author%3DLee%252CGY"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="23."><p class="c-article-references__text" id="ref-CR23">Giardina, G. et al. The catalytic activity of serine hydroxymethyltransferase is essential for de novo nuclear dTMP synthesis in lung cancer cells. <i>FEBS J.</i> <b>285</b>, 3238–3253 (2018).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1111/febs.14610" data-track-item_id="10.1111/febs.14610" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1111%252Ffebs.14610" aria-label="Article reference 23" data-doi="10.1111/febs.14610">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC1cXhsVGjurjN?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 23">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D30035852" aria-label="PubMed reference 23">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 23" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DThe%2520catalytic%2520activity%2520of%2520serine%2520hydroxymethyltransferase%2520is%2520essential%2520for%2520de%2520novo%2520nuclear%2520dTMP%2520synthesis%2520in%2520lung%2520cancer%2520cells%26journal%3DFEBS%2520J.%26doi%3D10.1111%252Ffebs.14610%26volume%3D285%26pages%3D3238-3253%26publication_year%3D2018%26author%3DGiardina%252CG"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="24."><p class="c-article-references__text" id="ref-CR24">Li, A. M. et al. Metabolic profiling reveals a dependency of human metastatic breast cancer on mitochondrial serine and one-carbon unit metabolism. <i>Mol. Cancer Res.</i> <b>18</b>, 599–611 (2020).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1158/1541-7786.MCR-19-0606" data-track-item_id="10.1158/1541-7786.MCR-19-0606" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1158%252F1541-7786.MCR-19-0606" aria-label="Article reference 24" data-doi="10.1158/1541-7786.MCR-19-0606">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3cXhvVejtbjE?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 24">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D31941752" aria-label="PubMed reference 24">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7127984" aria-label="PubMed Central reference 24">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 24" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DMetabolic%2520profiling%2520reveals%2520a%2520dependency%2520of%2520human%2520metastatic%2520breast%2520cancer%2520on%2520mitochondrial%2520serine%2520and%2520one-carbon%2520unit%2520metabolism%26journal%3DMol.%2520Cancer%2520Res.%26doi%3D10.1158%252F1541-7786.MCR-19-0606%26volume%3D18%26pages%3D599-611%26publication_year%3D2020%26author%3DLi%252CAM"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="25."><p class="c-article-references__text" id="ref-CR25">Wu, Z. Z. et al. Increased expression of SHMT2 is associated with poor prognosis and advanced pathological grade in oral squamous cell carcinoma. <i>Front Oncol.</i> <b>10</b>, 588530 (2020).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.3389/fonc.2020.588530" data-track-item_id="10.3389/fonc.2020.588530" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.3389%252Ffonc.2020.588530" aria-label="Article reference 25" data-doi="10.3389/fonc.2020.588530">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D33163414" aria-label="PubMed reference 25">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7581701" aria-label="PubMed Central reference 25">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 25" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DIncreased%2520expression%2520of%2520SHMT2%2520is%2520associated%2520with%2520poor%2520prognosis%2520and%2520advanced%2520pathological%2520grade%2520in%2520oral%2520squamous%2520cell%2520carcinoma%26journal%3DFront%2520Oncol.%26doi%3D10.3389%252Ffonc.2020.588530%26volume%3D10%26publication_year%3D2020%26author%3DWu%252CZZ"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="26."><p class="c-article-references__text" id="ref-CR26">Yang, C. C. et al. Folate-mediated one-carbon metabolism: a targeting strategy in cancer therapy. <i>Drug Discov. Today</i> <b>26</b>, 817–825 (2021).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.drudis.2020.12.006" data-track-item_id="10.1016/j.drudis.2020.12.006" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fj.drudis.2020.12.006" aria-label="Article reference 26" data-doi="10.1016/j.drudis.2020.12.006">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXhtVCltr0%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 26">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D33316375" aria-label="PubMed reference 26">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 26" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DFolate-mediated%2520one-carbon%2520metabolism%253A%2520a%2520targeting%2520strategy%2520in%2520cancer%2520therapy%26journal%3DDrug%2520Discov.%2520Today%26doi%3D10.1016%252Fj.drudis.2020.12.006%26volume%3D26%26pages%3D817-825%26publication_year%3D2021%26author%3DYang%252CCC"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="27."><p class="c-article-references__text" id="ref-CR27">Cui, X. M. et al. SHMT2 drives the progression of colorectal cancer by regulating UHRF1 expression. <i>Can. J. Gastroenterol.</i> <b>2022</b>, 3758697 (2022).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 27" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DSHMT2%2520drives%2520the%2520progression%2520of%2520colorectal%2520cancer%2520by%2520regulating%2520UHRF1%2520expression%26journal%3DCan.%2520J.%2520Gastroenterol.%26volume%3D2022%26publication_year%3D2022%26author%3DCui%252CXM"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="28."><p class="c-article-references__text" id="ref-CR28">Zeng, Y. et al. Roles of mitochondrial serine hydroxymethyltransferase 2 (SHMT2) in human carcinogenesis. <i>J. Cancer</i> <b>12</b>, 5888–5894 (2021).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.7150/jca.60170" data-track-item_id="10.7150/jca.60170" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.7150%252Fjca.60170" aria-label="Article reference 28" data-doi="10.7150/jca.60170">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXislykurzF?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 28">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D34476002" aria-label="PubMed reference 28">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8408114" aria-label="PubMed Central reference 28">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 28" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DRoles%2520of%2520mitochondrial%2520serine%2520hydroxymethyltransferase%25202%2520%2528SHMT2%2529%2520in%2520human%2520carcinogenesis%26journal%3DJ.%2520Cancer%26doi%3D10.7150%252Fjca.60170%26volume%3D12%26pages%3D5888-5894%26publication_year%3D2021%26author%3DZeng%252CY"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="29."><p class="c-article-references__text" id="ref-CR29">Du, J. et al. Serine hydroxymethyltransferase 2 predicts unfavorable outcomes in multiple cancer: a systematic review and meta-analysis. <i>Transl. Cancer Res</i> <b>11</b>, 444–455 (2022).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.21037/tcr-21-2485" data-track-item_id="10.21037/tcr-21-2485" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.21037%252Ftcr-21-2485" aria-label="Article reference 29" data-doi="10.21037/tcr-21-2485">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB38XpsFKku7s%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 29">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D35402174" aria-label="PubMed reference 29">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8990865" aria-label="PubMed Central reference 29">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 29" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DSerine%2520hydroxymethyltransferase%25202%2520predicts%2520unfavorable%2520outcomes%2520in%2520multiple%2520cancer%253A%2520a%2520systematic%2520review%2520and%2520meta-analysis%26journal%3DTransl.%2520Cancer%2520Res%26doi%3D10.21037%252Ftcr-21-2485%26volume%3D11%26pages%3D444-455%26publication_year%3D2022%26author%3DDu%252CJ"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="30."><p class="c-article-references__text" id="ref-CR30">Pranzini, E. et al. SHMT2-mediated mitochondrial serine metabolism drives 5-FU resistance by fueling nucleotide biosynthesis. <i>Cell Rep.</i> <b>40</b>, 111233 (2022).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.celrep.2022.111233" data-track-item_id="10.1016/j.celrep.2022.111233" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fj.celrep.2022.111233" aria-label="Article reference 30" data-doi="10.1016/j.celrep.2022.111233">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB38XitFKgtL%2FO?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 30">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D35977477" aria-label="PubMed reference 30">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 30" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DSHMT2-mediated%2520mitochondrial%2520serine%2520metabolism%2520drives%25205-FU%2520resistance%2520by%2520fueling%2520nucleotide%2520biosynthesis%26journal%3DCell%2520Rep.%26doi%3D10.1016%252Fj.celrep.2022.111233%26volume%3D40%26publication_year%3D2022%26author%3DPranzini%252CE"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="31."><p class="c-article-references__text" id="ref-CR31">Clark, R. A., Qiao, J., Jacobson, J. C. & Chung, D. H. Induction of serine hydroxymethyltransferase 2 promotes tumorigenesis and metastasis in neuroblastoma. <i>Oncotarget</i> <b>13</b>, 32–45 (2022).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.18632/oncotarget.28168" data-track-item_id="10.18632/oncotarget.28168" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.18632%252Foncotarget.28168" aria-label="Article reference 31" data-doi="10.18632/oncotarget.28168">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D35018218" aria-label="PubMed reference 31">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8735882" aria-label="PubMed Central reference 31">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 31" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DInduction%2520of%2520serine%2520hydroxymethyltransferase%25202%2520promotes%2520tumorigenesis%2520and%2520metastasis%2520in%2520neuroblastoma%26journal%3DOncotarget%26doi%3D10.18632%252Foncotarget.28168%26volume%3D13%26pages%3D32-45%26publication_year%3D2022%26author%3DClark%252CRA%26author%3DQiao%252CJ%26author%3DJacobson%252CJC%26author%3DChung%252CDH"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="32."><p class="c-article-references__text" id="ref-CR32">Cuthbertson, C. R., Arabzada, Z., Bankhead, A., Kyani, A. & Neamati, N. A review of small-molecule inhibitors of one-carbon enzymes: SHMT2 and MTHFD2 in the Spotlight. <i>ACS Pharm. Transl.</i> <b>4</b>, 624–646 (2021).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/acsptsci.0c00223" data-track-item_id="10.1021/acsptsci.0c00223" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Facsptsci.0c00223" aria-label="Article reference 32" data-doi="10.1021/acsptsci.0c00223">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXlt1Klu7k%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 32">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 32" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DA%2520review%2520of%2520small-molecule%2520inhibitors%2520of%2520one-carbon%2520enzymes%253A%2520SHMT2%2520and%2520MTHFD2%2520in%2520the%2520Spotlight%26journal%3DACS%2520Pharm.%2520Transl.%26doi%3D10.1021%252Facsptsci.0c00223%26volume%3D4%26pages%3D624-646%26publication_year%3D2021%26author%3DCuthbertson%252CCR%26author%3DArabzada%252CZ%26author%3DBankhead%252CA%26author%3DKyani%252CA%26author%3DNeamati%252CN"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="33."><p class="c-article-references__text" id="ref-CR33">Stine, Z. E., Schug, Z. T., Salvino, J. M. & Dang, C. V. Targeting cancer metabolism in the era of precision oncology. <i>Nat. Rev. Drug Discov.</i> <b>21</b>, 141–162 (2022).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1038/s41573-021-00339-6" data-track-item_id="10.1038/s41573-021-00339-6" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1038%252Fs41573-021-00339-6" aria-label="Article reference 33" data-doi="10.1038/s41573-021-00339-6">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXis1OisrnJ?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 33">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D34862480" aria-label="PubMed reference 33">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 33" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DTargeting%2520cancer%2520metabolism%2520in%2520the%2520era%2520of%2520precision%2520oncology%26journal%3DNat.%2520Rev.%2520Drug%2520Discov.%26doi%3D10.1038%252Fs41573-021-00339-6%26volume%3D21%26pages%3D141-162%26publication_year%3D2022%26author%3DStine%252CZE%26author%3DSchug%252CZT%26author%3DSalvino%252CJM%26author%3DDang%252CCV"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="34."><p class="c-article-references__text" id="ref-CR34">Han, Y. et al. Identification of three new compounds that directly target human serine hydroxymethyltransferase 2. <i>Chem. Biol. Drug Des.</i> <b>97</b>, 221–230 (2021).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1111/cbdd.13774" data-track-item_id="10.1111/cbdd.13774" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1111%252Fcbdd.13774" aria-label="Article reference 34" data-doi="10.1111/cbdd.13774">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3cXhvVamsrnL?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 34">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D32779873" aria-label="PubMed reference 34">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 34" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DIdentification%2520of%2520three%2520new%2520compounds%2520that%2520directly%2520target%2520human%2520serine%2520hydroxymethyltransferase%25202%26journal%3DChem.%2520Biol.%2520Drug%2520Des.%26doi%3D10.1111%252Fcbdd.13774%26volume%3D97%26pages%3D221-230%26publication_year%3D2021%26author%3DHan%252CY"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="35."><p class="c-article-references__text" id="ref-CR35">Garcia-Canaveras, J. C. et al. SHMT inhibition is effective and synergizes with methotrexate in T-cell acute lymphoblastic leukemia. <i>Leukemia</i> <b>35</b>, 377–388 (2021).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1038/s41375-020-0845-6" data-track-item_id="10.1038/s41375-020-0845-6" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1038%252Fs41375-020-0845-6" aria-label="Article reference 35" data-doi="10.1038/s41375-020-0845-6">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3cXovFKntLY%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 35">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D32382081" aria-label="PubMed reference 35">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 35" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DSHMT%2520inhibition%2520is%2520effective%2520and%2520synergizes%2520with%2520methotrexate%2520in%2520T-cell%2520acute%2520lymphoblastic%2520leukemia%26journal%3DLeukemia%26doi%3D10.1038%252Fs41375-020-0845-6%26volume%3D35%26pages%3D377-388%26publication_year%3D2021%26author%3DGarcia-Canaveras%252CJC"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="36."><p class="c-article-references__text" id="ref-CR36">Pikman, Y. et al. Targeting serine hydroxymethyltransferases 1 and 2 for T-cell acute lymphoblastic leukemia therapy. <i>Leukemia</i> <b>36</b>, 348–360 (2022).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1038/s41375-021-01361-8" data-track-item_id="10.1038/s41375-021-01361-8" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1038%252Fs41375-021-01361-8" aria-label="Article reference 36" data-doi="10.1038/s41375-021-01361-8">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXitVGgtLzL?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 36">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D34341479" aria-label="PubMed reference 36">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 36" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DTargeting%2520serine%2520hydroxymethyltransferases%25201%2520and%25202%2520for%2520T-cell%2520acute%2520lymphoblastic%2520leukemia%2520therapy%26journal%3DLeukemia%26doi%3D10.1038%252Fs41375-021-01361-8%26volume%3D36%26pages%3D348-360%26publication_year%3D2022%26author%3DPikman%252CY"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="37."><p class="c-article-references__text" id="ref-CR37">Ducker, G. S. et al. Human SHMT inhibitors reveal defective glycine import as a targetable metabolic vulnerability of diffuse large B-cell lymphoma. <i>Proc. Natl Acad. Sci. USA</i> <b>114</b>, 11404–11409 (2017).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1073/pnas.1706617114" data-track-item_id="10.1073/pnas.1706617114" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1073%252Fpnas.1706617114" aria-label="Article reference 37" data-doi="10.1073/pnas.1706617114">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC2sXhs1aisr7N?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 37">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D29073064" aria-label="PubMed reference 37">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5664509" aria-label="PubMed Central reference 37">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 37" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DHuman%2520SHMT%2520inhibitors%2520reveal%2520defective%2520glycine%2520import%2520as%2520a%2520targetable%2520metabolic%2520vulnerability%2520of%2520diffuse%2520large%2520B-cell%2520lymphoma%26journal%3DProc.%2520Natl%2520Acad.%2520Sci.%2520USA%26doi%3D10.1073%252Fpnas.1706617114%26volume%3D114%26pages%3D11404-11409%26publication_year%3D2017%26author%3DDucker%252CGS"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="38."><p class="c-article-references__text" id="ref-CR38">McConnell, D. B. Biotin’s lessons in drug design. <i>J. Med Chem.</i> <b>64</b>, 16319–16327 (2021).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/acs.jmedchem.1c00975" data-track-item_id="10.1021/acs.jmedchem.1c00975" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Facs.jmedchem.1c00975" aria-label="Article reference 38" data-doi="10.1021/acs.jmedchem.1c00975">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXisVyltrzN?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 38">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D34784474" aria-label="PubMed reference 38">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 38" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DBiotin%25E2%2580%2599s%2520lessons%2520in%2520drug%2520design%26journal%3DJ.%2520Med%2520Chem.%26doi%3D10.1021%252Facs.jmedchem.1c00975%26volume%3D64%26pages%3D16319-16327%26publication_year%3D2021%26author%3DMcConnell%252CDB"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="39."><p class="c-article-references__text" id="ref-CR39">Engler, N., Ostermann, A., Niimura, N. & Parak, F. G. Hydrogen atoms in proteins: positions and dynamics. <i>Proc. Natl Acad. Sci. USA</i> <b>100</b>, 10243–10248 (2003).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1073/pnas.1834279100" data-track-item_id="10.1073/pnas.1834279100" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1073%252Fpnas.1834279100" aria-label="Article reference 39" data-doi="10.1073/pnas.1834279100">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD3sXntFygur4%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 39">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D12937341" aria-label="PubMed reference 39">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC193546" aria-label="PubMed Central reference 39">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 39" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DHydrogen%2520atoms%2520in%2520proteins%253A%2520positions%2520and%2520dynamics%26journal%3DProc.%2520Natl%2520Acad.%2520Sci.%2520USA%26doi%3D10.1073%252Fpnas.1834279100%26volume%3D100%26pages%3D10243-10248%26publication_year%3D2003%26author%3DEngler%252CN%26author%3DOstermann%252CA%26author%3DNiimura%252CN%26author%3DParak%252CFG"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="40."><p class="c-article-references__text" id="ref-CR40">Bax, B., Chung, C. & Edge, C. Getting the chemistry right: protonation, tautomers and the importance of H atoms in biological chemistry. <i>Acta Crystallogr. Sect. D.</i> <b>73</b>, 131–140 (2017).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S2059798316020283" data-track-item_id="10.1107/S2059798316020283" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS2059798316020283" aria-label="Article reference 40" data-doi="10.1107/S2059798316020283">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC2sXitlGgu70%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 40">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 40" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DGetting%2520the%2520chemistry%2520right%253A%2520protonation%252C%2520tautomers%2520and%2520the%2520importance%2520of%2520H%2520atoms%2520in%2520biological%2520chemistry%26journal%3DActa%2520Crystallogr.%2520Sect.%2520D.%26doi%3D10.1107%252FS2059798316020283%26volume%3D73%26pages%3D131-140%26publication_year%3D2017%26author%3DBax%252CB%26author%3DChung%252CC%26author%3DEdge%252CC"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="41."><p class="c-article-references__text" id="ref-CR41">Gardberg, A. S. et al. Unambiguous determination of H-atom positions: comparing results from neutron and high-resolution X-ray crystallography. <i>Acta Crystallogr. Sect. D.-Struct. Biol.</i> <b>66</b>, 558–567 (2010).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444910005494" data-track-item_id="10.1107/S0907444910005494" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444910005494" aria-label="Article reference 41" data-doi="10.1107/S0907444910005494">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC3cXls1WgsrY%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 41">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 41" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DUnambiguous%2520determination%2520of%2520H-atom%2520positions%253A%2520comparing%2520results%2520from%2520neutron%2520and%2520high-resolution%2520X-ray%2520crystallography%26journal%3DActa%2520Crystallogr.%2520Sect.%2520D.-Struct.%2520Biol.%26doi%3D10.1107%252FS0907444910005494%26volume%3D66%26pages%3D558-567%26publication_year%3D2010%26author%3DGardberg%252CAS"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="42."><p class="c-article-references__text" id="ref-CR42">Niimura, N. & Podjarny, A. <i>Neutron Protein Crystallography: Hydrogen, Protons, and Hydration in Bio-macromolecules</i>, 232 (Oxford University Press, Oxford, UK, 2011).</p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="43."><p class="c-article-references__text" id="ref-CR43">Gerlits, O. et al. Long-range electrostatics-induced two-proton transfer captured by neutron crystallography in an enzyme catalytic site. <i>Angew. Chem. Int Ed. Engl.</i> <b>55</b>, 4924–4927 (2016).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1002/anie.201509989" data-track-item_id="10.1002/anie.201509989" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1002%252Fanie.201509989" aria-label="Article reference 43" data-doi="10.1002/anie.201509989">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC28XktVaju70%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 43">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D26958828" aria-label="PubMed reference 43">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4944821" aria-label="PubMed Central reference 43">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 43" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DLong-range%2520electrostatics-induced%2520two-proton%2520transfer%2520captured%2520by%2520neutron%2520crystallography%2520in%2520an%2520enzyme%2520catalytic%2520site%26journal%3DAngew.%2520Chem.%2520Int%2520Ed.%2520Engl.%26doi%3D10.1002%252Fanie.201509989%26volume%3D55%26pages%3D4924-4927%26publication_year%3D2016%26author%3DGerlits%252CO"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="44."><p class="c-article-references__text" id="ref-CR44">Dajnowicz, S. et al. Direct visualization of critical hydrogen atoms in a pyridoxal 5’-phosphate enzyme. <i>Nat. Commun.</i> <b>8</b>, 955 (2017).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1038/s41467-017-01060-y" data-track-item_id="10.1038/s41467-017-01060-y" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1038%252Fs41467-017-01060-y" aria-label="Article reference 44" data-doi="10.1038/s41467-017-01060-y">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D29038582" aria-label="PubMed reference 44">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5643538" aria-label="PubMed Central reference 44">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 44" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DDirect%2520visualization%2520of%2520critical%2520hydrogen%2520atoms%2520in%2520a%2520pyridoxal%25205%25E2%2580%2599-phosphate%2520enzyme%26journal%3DNat.%2520Commun.%26doi%3D10.1038%252Fs41467-017-01060-y%26volume%3D8%26publication_year%3D2017%26author%3DDajnowicz%252CS"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="45."><p class="c-article-references__text" id="ref-CR45">Drago, V. N. et al. An N···H···N low-barrier hydrogen bond preorganizes the catalytic site of aspartate aminotransferase to facilitate the second half-reaction. <i>Chem. Sci.</i> <b>13</b>, 10057–10065 (2022).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1039/D2SC02285K" data-track-item_id="10.1039/D2SC02285K" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1039%252FD2SC02285K" aria-label="Article reference 45" data-doi="10.1039/D2SC02285K">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB38XitFCisL7E?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 45">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D36128223" aria-label="PubMed reference 45">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9430417" aria-label="PubMed Central reference 45">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 45" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DAn%2520N%25C2%25B7%25C2%25B7%25C2%25B7H%25C2%25B7%25C2%25B7%25C2%25B7N%2520low-barrier%2520hydrogen%2520bond%2520preorganizes%2520the%2520catalytic%2520site%2520of%2520aspartate%2520aminotransferase%2520to%2520facilitate%2520the%2520second%2520half-reaction%26journal%3DChem.%2520Sci.%26doi%3D10.1039%252FD2SC02285K%26volume%3D13%26pages%3D10057-10065%26publication_year%3D2022%26author%3DDrago%252CVN"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="46."><p class="c-article-references__text" id="ref-CR46">Fisher, S. Z., Aggarwal, M., Kovalevsky, A. Y., Silverman, D. N. & McKenna, R. Neutron diffraction of acetazolamide-bound human carbonic anhydrase II reveals atomic details of drug binding. <i>J. Am. Chem. Soc.</i> <b>134</b>, 14726–14729 (2012).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/ja3068098" data-track-item_id="10.1021/ja3068098" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Fja3068098" aria-label="Article reference 46" data-doi="10.1021/ja3068098">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC38Xht1yhsLbM?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 46">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D22928733" aria-label="PubMed reference 46">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3524527" aria-label="PubMed Central reference 46">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 46" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DNeutron%2520diffraction%2520of%2520acetazolamide-bound%2520human%2520carbonic%2520anhydrase%2520II%2520reveals%2520atomic%2520details%2520of%2520drug%2520binding%26journal%3DJ.%2520Am.%2520Chem.%2520Soc.%26doi%3D10.1021%252Fja3068098%26volume%3D134%26pages%3D14726-14729%26publication_year%3D2012%26author%3DFisher%252CSZ%26author%3DAggarwal%252CM%26author%3DKovalevsky%252CAY%26author%3DSilverman%252CDN%26author%3DMcKenna%252CR"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="47."><p class="c-article-references__text" id="ref-CR47">Weber, I. T. et al. Joint X-ray/neutron crystallographic study of HIV-1 protease with clinical inhibitor amprenavir: insights for drug design. <i>J. Med. Chem.</i> <b>56</b>, 5631–5635 (2013).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/jm400684f" data-track-item_id="10.1021/jm400684f" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Fjm400684f" aria-label="Article reference 47" data-doi="10.1021/jm400684f">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC3sXpsFWqs7o%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 47">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D23772563" aria-label="PubMed reference 47">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 47" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DJoint%2520X-ray%252Fneutron%2520crystallographic%2520study%2520of%2520HIV-1%2520protease%2520with%2520clinical%2520inhibitor%2520amprenavir%253A%2520insights%2520for%2520drug%2520design%26journal%3DJ.%2520Med.%2520Chem.%26doi%3D10.1021%252Fjm400684f%26volume%3D56%26pages%3D5631-5635%26publication_year%3D2013%26author%3DWeber%252CIT"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="48."><p class="c-article-references__text" id="ref-CR48">Manzoni, F. et al. Elucidation of hydrogen bonding patterns in ligand-free, lactose- and glycerol-bound galectin-3c by neutron crystallography to guide drug design. <i>J. Med. Chem.</i> <b>61</b>, 4412–4420 (2018).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/acs.jmedchem.8b00081" data-track-item_id="10.1021/acs.jmedchem.8b00081" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Facs.jmedchem.8b00081" aria-label="Article reference 48" data-doi="10.1021/acs.jmedchem.8b00081">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC1cXotVaiu7g%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 48">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D29672051" aria-label="PubMed reference 48">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 48" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DElucidation%2520of%2520hydrogen%2520bonding%2520patterns%2520in%2520ligand-free%252C%2520lactose-%2520and%2520glycerol-bound%2520galectin-3c%2520by%2520neutron%2520crystallography%2520to%2520guide%2520drug%2520design%26journal%3DJ.%2520Med.%2520Chem.%26doi%3D10.1021%252Facs.jmedchem.8b00081%26volume%3D61%26pages%3D4412-4420%26publication_year%3D2018%26author%3DManzoni%252CF"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="49."><p class="c-article-references__text" id="ref-CR49">Kneller, D. W. et al. Structural, electronic, and electrostatic determinants for inhibitor binding to subsites S1 and S2 in SARS-CoV-2 main protease. <i>J. Med Chem.</i> <b>64</b>, 17366–17383 (2021).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/acs.jmedchem.1c01475" data-track-item_id="10.1021/acs.jmedchem.1c01475" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Facs.jmedchem.1c01475" aria-label="Article reference 49" data-doi="10.1021/acs.jmedchem.1c01475">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXitlajurfE?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 49">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D34705466" aria-label="PubMed reference 49">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 49" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DStructural%252C%2520electronic%252C%2520and%2520electrostatic%2520determinants%2520for%2520inhibitor%2520binding%2520to%2520subsites%2520S1%2520and%2520S2%2520in%2520SARS-CoV-2%2520main%2520protease%26journal%3DJ.%2520Med%2520Chem.%26doi%3D10.1021%252Facs.jmedchem.1c01475%26volume%3D64%26pages%3D17366-17383%26publication_year%3D2021%26author%3DKneller%252CDW"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="50."><p class="c-article-references__text" id="ref-CR50">Kneller, D. et al. Covalent narlaprevir- and boceprevir-derived hybrid inhibitors of SARS-CoV-2 main protease: room-temperature X-ray and neutron crystallography, binding thermodynamics, and antiviral activity. <i>Res. Sq</i>. <a href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.21203/rs.3.rs-1318037/v1" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="10.21203/rs.3.rs-1318037/v1">https://doi.org/10.21203/rs.3.rs-1318037/v1</a> (2022).</p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="51."><p class="c-article-references__text" id="ref-CR51">Gerlits, O. et al. Zooming in on protons: neutron structure of protein kinase a trapped in a product complex. <i>Sci. Adv.</i> <b>5</b>, eaav0482 (2019).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1126/sciadv.aav0482" data-track-item_id="10.1126/sciadv.aav0482" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1126%252Fsciadv.aav0482" aria-label="Article reference 51" data-doi="10.1126/sciadv.aav0482">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC1MXhvFWgt7nM?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 51">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D30906862" aria-label="PubMed reference 51">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6426457" aria-label="PubMed Central reference 51">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 51" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DZooming%2520in%2520on%2520protons%253A%2520neutron%2520structure%2520of%2520protein%2520kinase%2520a%2520trapped%2520in%2520a%2520product%2520complex%26journal%3DSci.%2520Adv.%26doi%3D10.1126%252Fsciadv.aav0482%26volume%3D5%26publication_year%3D2019%26author%3DGerlits%252CO"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="52."><p class="c-article-references__text" id="ref-CR52">Kumar, M. et al. Visualizing tetrahedral oxyanion bound in HIV-1 protease using neutrons: implications for the catalytic mechanism and drug design. <i>ACS Omega</i> <b>5</b>, 11605–11617 (2020).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/acsomega.0c00835" data-track-item_id="10.1021/acsomega.0c00835" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Facsomega.0c00835" aria-label="Article reference 52" data-doi="10.1021/acsomega.0c00835">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3cXptF2hurs%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 52">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D32478251" aria-label="PubMed reference 52">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7254801" aria-label="PubMed Central reference 52">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 52" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DVisualizing%2520tetrahedral%2520oxyanion%2520bound%2520in%2520HIV-1%2520protease%2520using%2520neutrons%253A%2520implications%2520for%2520the%2520catalytic%2520mechanism%2520and%2520drug%2520design%26journal%3DACS%2520Omega%26doi%3D10.1021%252Facsomega.0c00835%26volume%3D5%26pages%3D11605-11617%26publication_year%3D2020%26author%3DKumar%252CM"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="53."><p class="c-article-references__text" id="ref-CR53">Renwick, S. B., Snell, K. & Baumann, U. The crystal structure of human cytosolic serine hydroxymethyltransferase: a target for cancer chemotherapy. <i>Structure</i> <b>6</b>, 1105–1116 (1998).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/S0969-2126(98)00112-9" data-track-item_id="10.1016/S0969-2126(98)00112-9" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252FS0969-2126%252898%252900112-9" aria-label="Article reference 53" data-doi="10.1016/S0969-2126(98)00112-9">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaK1cXmsVKjt7o%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 53">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D9753690" aria-label="PubMed reference 53">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 53" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DThe%2520crystal%2520structure%2520of%2520human%2520cytosolic%2520serine%2520hydroxymethyltransferase%253A%2520a%2520target%2520for%2520cancer%2520chemotherapy%26journal%3DStructure%26doi%3D10.1016%252FS0969-2126%252898%252900112-9%26volume%3D6%26pages%3D1105-1116%26publication_year%3D1998%26author%3DRenwick%252CSB%26author%3DSnell%252CK%26author%3DBaumann%252CU"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="54."><p class="c-article-references__text" id="ref-CR54">Trivedi, V. et al. Crystal structure of binary and ternary complexes of serine hydroxymethyltransferase from <i>Bacillus</i> stearothermophilus - Insights into the catalytic mechanism. <i>J. Biol. Chem.</i> <b>277</b>, 17161–17169 (2002).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1074/jbc.M111976200" data-track-item_id="10.1074/jbc.M111976200" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1074%252Fjbc.M111976200" aria-label="Article reference 54" data-doi="10.1074/jbc.M111976200">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD38XjslWgsrc%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 54">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D11877399" aria-label="PubMed reference 54">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 54" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DCrystal%2520structure%2520of%2520binary%2520and%2520ternary%2520complexes%2520of%2520serine%2520hydroxymethyltransferase%2520from%2520Bacillus%2520stearothermophilus%2520-%2520Insights%2520into%2520the%2520catalytic%2520mechanism%26journal%3DJ.%2520Biol.%2520Chem.%26doi%3D10.1074%252Fjbc.M111976200%26volume%3D277%26pages%3D17161-17169%26publication_year%3D2002%26author%3DTrivedi%252CV"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="55."><p class="c-article-references__text" id="ref-CR55">Szebenyi, D. M. E., Musayev, F. N., di Salvo, M. L., Safo, M. K. & Schirch, V. Serine hydroxymethyltransferase: role of Glu75 and evidence that serine is cleaved by a retroaldol mechanism. <i>Biochemistry</i> <b>43</b>, 6865–6876 (2004).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/bi049791y" data-track-item_id="10.1021/bi049791y" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Fbi049791y" aria-label="Article reference 55" data-doi="10.1021/bi049791y">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD2cXjslOitbk%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 55">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D15170323" aria-label="PubMed reference 55">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 55" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DSerine%2520hydroxymethyltransferase%253A%2520role%2520of%2520Glu75%2520and%2520evidence%2520that%2520serine%2520is%2520cleaved%2520by%2520a%2520retroaldol%2520mechanism%26journal%3DBiochemistry%26doi%3D10.1021%252Fbi049791y%26volume%3D43%26pages%3D6865-6876%26publication_year%3D2004%26author%3DSzebenyi%252CDME%26author%3DMusayev%252CFN%26author%3DSalvo%252CML%26author%3DSafo%252CMK%26author%3DSchirch%252CV"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="56."><p class="c-article-references__text" id="ref-CR56">Schirch, V. & Szebenyi, D. M. Serine hydroxymethyltransferase revisited. <i>Curr. Opin. Chem. Biol.</i> <b>9</b>, 482–487 (2005).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.cbpa.2005.08.017" data-track-item_id="10.1016/j.cbpa.2005.08.017" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fj.cbpa.2005.08.017" aria-label="Article reference 56" data-doi="10.1016/j.cbpa.2005.08.017">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD2MXhtVehs7rI?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 56">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D16125438" aria-label="PubMed reference 56">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 56" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DSerine%2520hydroxymethyltransferase%2520revisited%26journal%3DCurr.%2520Opin.%2520Chem.%2520Biol.%26doi%3D10.1016%252Fj.cbpa.2005.08.017%26volume%3D9%26pages%3D482-487%26publication_year%3D2005%26author%3DSchirch%252CV%26author%3DSzebenyi%252CDM"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="57."><p class="c-article-references__text" id="ref-CR57">Jagath, J. R. et al. Importance of the amino terminus in maintenance of oligomeric structure of sheep liver cytosolic serine hydroxymethyltransferase. <i>Eur. J. Biochem</i> <b>247</b>, 372–379 (1997).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1111/j.1432-1033.1997.00372.x" data-track-item_id="10.1111/j.1432-1033.1997.00372.x" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1111%252Fj.1432-1033.1997.00372.x" aria-label="Article reference 57" data-doi="10.1111/j.1432-1033.1997.00372.x">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaK2sXksFGhs7Y%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 57">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D9249049" aria-label="PubMed reference 57">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 57" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DImportance%2520of%2520the%2520amino%2520terminus%2520in%2520maintenance%2520of%2520oligomeric%2520structure%2520of%2520sheep%2520liver%2520cytosolic%2520serine%2520hydroxymethyltransferase%26journal%3DEur.%2520J.%2520Biochem%26doi%3D10.1111%252Fj.1432-1033.1997.00372.x%26volume%3D247%26pages%3D372-379%26publication_year%3D1997%26author%3DJagath%252CJR"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="58."><p class="c-article-references__text" id="ref-CR58">Rao, N. A., Ambili, M., Jala, V. R., Subramanya, H. S. & Savithri, H. S. Structure-function relationship in serine hydroxymethyltransferase. <i>Biochim. Biophys. Acta-Proteins Proteom.</i> <b>1647</b>, 24–29 (2003).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/S1570-9639(03)00043-8" data-track-item_id="10.1016/S1570-9639(03)00043-8" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252FS1570-9639%252803%252900043-8" aria-label="Article reference 58" data-doi="10.1016/S1570-9639(03)00043-8">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 58" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DStructure-function%2520relationship%2520in%2520serine%2520hydroxymethyltransferase%26journal%3DBiochim.%2520Biophys.%2520Acta-Proteins%2520Proteom.%26doi%3D10.1016%252FS1570-9639%252803%252900043-8%26volume%3D1647%26pages%3D24-29%26publication_year%3D2003%26author%3DRao%252CNA%26author%3DAmbili%252CM%26author%3DJala%252CVR%26author%3DSubramanya%252CHS%26author%3DSavithri%252CHS"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="59."><p class="c-article-references__text" id="ref-CR59">Matthews, R. G. & Drummond, J. T. Providing one-carbon units for biological methylations - Mechanistic studies on serine hydroxymethyltransferase, methylenetetrahydrofolate reductase, and methyltetrahydrofolate-homocysteine methyltransferase. <i>Chem. Rev.</i> <b>90</b>, 1275–1290 (1990).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/cr00105a010" data-track-item_id="10.1021/cr00105a010" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Fcr00105a010" aria-label="Article reference 59" data-doi="10.1021/cr00105a010">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaK3cXmtVOjur0%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 59">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 59" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DProviding%2520one-carbon%2520units%2520for%2520biological%2520methylations%2520-%2520Mechanistic%2520studies%2520on%2520serine%2520hydroxymethyltransferase%252C%2520methylenetetrahydrofolate%2520reductase%252C%2520and%2520methyltetrahydrofolate-homocysteine%2520methyltransferase%26journal%3DChem.%2520Rev.%26doi%3D10.1021%252Fcr00105a010%26volume%3D90%26pages%3D1275-1290%26publication_year%3D1990%26author%3DMatthews%252CRG%26author%3DDrummond%252CJT"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="60."><p class="c-article-references__text" id="ref-CR60">Fernandes, H. S., Ramos, M. J. & Cerqueira, N. M. F. S. A. Catalytic mechanism of the serine hydroxymethyltransferase: a computational ONIOM QM/MM study. <i>ACS Catal.</i> <b>8</b>, 10096–10110 (2018).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/acscatal.8b02321" data-track-item_id="10.1021/acscatal.8b02321" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Facscatal.8b02321" aria-label="Article reference 60" data-doi="10.1021/acscatal.8b02321">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC1cXhslaqtr7E?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 60">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 60" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DCatalytic%2520mechanism%2520of%2520the%2520serine%2520hydroxymethyltransferase%253A%2520a%2520computational%2520ONIOM%2520QM%252FMM%2520study%26journal%3DACS%2520Catal.%26doi%3D10.1021%252Facscatal.8b02321%26volume%3D8%26pages%3D10096-10110%26publication_year%3D2018%26author%3DFernandes%252CHS%26author%3DRamos%252CMJ%26author%3DCerqueira%252CNMFSA"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="61."><p class="c-article-references__text" id="ref-CR61">Nonaka, H. et al. Design strategy for serine hydroxymethyltransferase probes based on retro-aldol-type reaction. <i>Nat. Commun.</i> <b>10</b>, 876 (2019).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1038/s41467-019-08833-7" data-track-item_id="10.1038/s41467-019-08833-7" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1038%252Fs41467-019-08833-7" aria-label="Article reference 61" data-doi="10.1038/s41467-019-08833-7">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D30787298" aria-label="PubMed reference 61">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6382819" aria-label="PubMed Central reference 61">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 61" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DDesign%2520strategy%2520for%2520serine%2520hydroxymethyltransferase%2520probes%2520based%2520on%2520retro-aldol-type%2520reaction%26journal%3DNat.%2520Commun.%26doi%3D10.1038%252Fs41467-019-08833-7%26volume%3D10%26publication_year%3D2019%26author%3DNonaka%252CH"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="62."><p class="c-article-references__text" id="ref-CR62">Scaletti, E., Jemth, A. S., Helleday, T. & Stenmark, P. Structural basis of inhibition of the human serine hydroxymethyltransferase SHMT2 by antifolate drugs. <i>FEBS Lett.</i> <b>593</b>, 1863–1873 (2019).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1002/1873-3468.13455" data-track-item_id="10.1002/1873-3468.13455" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1002%252F1873-3468.13455" aria-label="Article reference 62" data-doi="10.1002/1873-3468.13455">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC1MXhtFWksL3M?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 62">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D31127856" aria-label="PubMed reference 62">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 62" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DStructural%2520basis%2520of%2520inhibition%2520of%2520the%2520human%2520serine%2520hydroxymethyltransferase%2520SHMT2%2520by%2520antifolate%2520drugs%26journal%3DFEBS%2520Lett.%26doi%3D10.1002%252F1873-3468.13455%26volume%3D593%26pages%3D1863-1873%26publication_year%3D2019%26author%3DScaletti%252CE%26author%3DJemth%252CAS%26author%3DHelleday%252CT%26author%3DStenmark%252CP"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="63."><p class="c-article-references__text" id="ref-CR63">Ota, T. et al. Structural basis for selective inhibition of human serine hydroxymethyltransferase by secondary bile acid conjugate. <i>iScience</i> <b>24</b>, 102036 (2021).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.isci.2021.102036" data-track-item_id="10.1016/j.isci.2021.102036" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fj.isci.2021.102036" aria-label="Article reference 63" data-doi="10.1016/j.isci.2021.102036">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXht1ahs7jP?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 63">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D33521601" aria-label="PubMed reference 63">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7820547" aria-label="PubMed Central reference 63">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 63" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DStructural%2520basis%2520for%2520selective%2520inhibition%2520of%2520human%2520serine%2520hydroxymethyltransferase%2520by%2520secondary%2520bile%2520acid%2520conjugate%26journal%3DiScience%26doi%3D10.1016%252Fj.isci.2021.102036%26volume%3D24%26publication_year%3D2021%26author%3DOta%252CT"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="64."><p class="c-article-references__text" id="ref-CR64">Blakeley, M. P. & Podjarny, A. D. Neutron macromolecular crystallography. <i>Emerg. Top. Life Sci.</i> <b>2</b>, 39–55 (2018).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1042/ETLS20170083" data-track-item_id="10.1042/ETLS20170083" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1042%252FETLS20170083" aria-label="Article reference 64" data-doi="10.1042/ETLS20170083">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC1MXhvVOnsb%2FI?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 64">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D33525781" aria-label="PubMed reference 64">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 64" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DNeutron%2520macromolecular%2520crystallography%26journal%3DEmerg.%2520Top.%2520Life%2520Sci.%26doi%3D10.1042%252FETLS20170083%26volume%3D2%26pages%3D39-55%26publication_year%3D2018%26author%3DBlakeley%252CMP%26author%3DPodjarny%252CAD"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="65."><p class="c-article-references__text" id="ref-CR65">Schneider, G., Kack, H. & Lindqvist, Y. The manifold of vitamin B6 dependent enzymes. <i>Structure</i> <b>8</b>, R1–R6 (2000).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/S0969-2126(00)00085-X" data-track-item_id="10.1016/S0969-2126(00)00085-X" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252FS0969-2126%252800%252900085-X" aria-label="Article reference 65" data-doi="10.1016/S0969-2126(00)00085-X">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD3cXot1Kltw%3D%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 65">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D10673430" aria-label="PubMed reference 65">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 65" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DThe%2520manifold%2520of%2520vitamin%2520B6%2520dependent%2520enzymes%26journal%3DStructure%26doi%3D10.1016%252FS0969-2126%252800%252900085-X%26volume%3D8%26pages%3DR1-R6%26publication_year%3D2000%26author%3DSchneider%252CG%26author%3DKack%252CH%26author%3DLindqvist%252CY"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="66."><p class="c-article-references__text" id="ref-CR66">Scarsdale, J. N., Radaev, S., Kazanina, G., Schirch, V. & Wright, H. T. Crystal structure at 2.4 Å resolution of <i>E. coli</i> serine hydroxymethyltransferase in complex with glycine substrate and 5-formyl tetrahydrofolate11Edited by I. A. Wilson. <i>J. Mol. Biol.</i> <b>296</b>, 155–168 (2000).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1006/jmbi.1999.3453" data-track-item_id="10.1006/jmbi.1999.3453" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1006%252Fjmbi.1999.3453" aria-label="Article reference 66" data-doi="10.1006/jmbi.1999.3453">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD3cXotlShtw%3D%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 66">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D10656824" aria-label="PubMed reference 66">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 66" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DCrystal%2520structure%2520at%25202.4%2520%25C3%2585%2520resolution%2520of%2520E.%2520coli%2520serine%2520hydroxymethyltransferase%2520in%2520complex%2520with%2520glycine%2520substrate%2520and%25205-formyl%2520tetrahydrofolate11Edited%2520by%2520I.%2520A.%2520Wilson%26journal%3DJ.%2520Mol.%2520Biol.%26doi%3D10.1006%252Fjmbi.1999.3453%26volume%3D296%26pages%3D155-168%26publication_year%3D2000%26author%3DScarsdale%252CJN%26author%3DRadaev%252CS%26author%3DKazanina%252CG%26author%3DSchirch%252CV%26author%3DWright%252CHT"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="67."><p class="c-article-references__text" id="ref-CR67">Szebenyi, D. M. E., Liu, X. W., Kriksunov, I. A., Stover, P. J. & Thiel, D. J. Structure of a murine cytoplasmic serine hydroxymethyltransferase quinonoid ternary complex: Evidence for asymmetric obligate dimers. <i>Biochemistry</i> <b>39</b>, 13313–13323 (2000).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/bi000635a" data-track-item_id="10.1021/bi000635a" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Fbi000635a" aria-label="Article reference 67" data-doi="10.1021/bi000635a">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD3cXntVOmtrw%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 67">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D11063567" aria-label="PubMed reference 67">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 67" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DStructure%2520of%2520a%2520murine%2520cytoplasmic%2520serine%2520hydroxymethyltransferase%2520quinonoid%2520ternary%2520complex%253A%2520Evidence%2520for%2520asymmetric%2520obligate%2520dimers%26journal%3DBiochemistry%26doi%3D10.1021%252Fbi000635a%26volume%3D39%26pages%3D13313-13323%26publication_year%3D2000%26author%3DSzebenyi%252CDME%26author%3DLiu%252CXW%26author%3DKriksunov%252CIA%26author%3DStover%252CPJ%26author%3DThiel%252CDJ"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="68."><p class="c-article-references__text" id="ref-CR68">Casasnovas, R., Salvà, A., Frau, J., Donoso, J. & Muñoz, F. Theoretical study on the distribution of atomic charges in the Schiff bases of 3-hydroxypyridine-4-aldehyde and alanine. The effect of the protonation state of the pyridine and imine nitrogen atoms. <i>Chem. Phys.</i> <b>355</b>, 149–156 (2009).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.chemphys.2008.12.006" data-track-item_id="10.1016/j.chemphys.2008.12.006" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fj.chemphys.2008.12.006" aria-label="Article reference 68" data-doi="10.1016/j.chemphys.2008.12.006">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD1MXmvVGrtA%3D%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 68">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 68" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DTheoretical%2520study%2520on%2520the%2520distribution%2520of%2520atomic%2520charges%2520in%2520the%2520Schiff%2520bases%2520of%25203-hydroxypyridine-4-aldehyde%2520and%2520alanine.%2520The%2520effect%2520of%2520the%2520protonation%2520state%2520of%2520the%2520pyridine%2520and%2520imine%2520nitrogen%2520atoms%26journal%3DChem.%2520Phys.%26doi%3D10.1016%252Fj.chemphys.2008.12.006%26volume%3D355%26pages%3D149-156%26publication_year%3D2009%26author%3DCasasnovas%252CR%26author%3DSalv%25C3%25A0%252CA%26author%3DFrau%252CJ%26author%3DDonoso%252CJ%26author%3DMu%25C3%25B1oz%252CF"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="69."><p class="c-article-references__text" id="ref-CR69">Griswold, W. R. & Toney, M. D. Role of the pyridine nitrogen in pyridoxal 5’-phosphate catalysis: activity of three classes of PLP enzymes reconstituted with deazapyridoxal 5’-phosphate. <i>J. Am. Chem. Soc.</i> <b>133</b>, 14823–14830 (2011).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/ja2061006" data-track-item_id="10.1021/ja2061006" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Fja2061006" aria-label="Article reference 69" data-doi="10.1021/ja2061006">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC3MXhtVOns7rI?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 69">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D21827189" aria-label="PubMed reference 69">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 69" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DRole%2520of%2520the%2520pyridine%2520nitrogen%2520in%2520pyridoxal%25205%25E2%2580%2599-phosphate%2520catalysis%253A%2520activity%2520of%2520three%2520classes%2520of%2520PLP%2520enzymes%2520reconstituted%2520with%2520deazapyridoxal%25205%25E2%2580%2599-phosphate%26journal%3DJ.%2520Am.%2520Chem.%2520Soc.%26doi%3D10.1021%252Fja2061006%26volume%3D133%26pages%3D14823-14830%26publication_year%3D2011%26author%3DGriswold%252CWR%26author%3DToney%252CMD"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="70."><p class="c-article-references__text" id="ref-CR70">Mueser, T. C., Drago, V., Kovalevsky, A. & Dajnowicz, S. Pyridoxal 5’-phosphate dependent reactions: analyzing the mechanism of aspartate aminotransferase. <i>Methods Enzymol.</i> <b>634</b>, 333–359 (2020).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/bs.mie.2020.01.009" data-track-item_id="10.1016/bs.mie.2020.01.009" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fbs.mie.2020.01.009" aria-label="Article reference 70" data-doi="10.1016/bs.mie.2020.01.009">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXktFansL0%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 70">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D32093839" aria-label="PubMed reference 70">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 70" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DPyridoxal%25205%25E2%2580%2599-phosphate%2520dependent%2520reactions%253A%2520analyzing%2520the%2520mechanism%2520of%2520aspartate%2520aminotransferase%26journal%3DMethods%2520Enzymol.%26doi%3D10.1016%252Fbs.mie.2020.01.009%26volume%3D634%26pages%3D333-359%26publication_year%3D2020%26author%3DMueser%252CTC%26author%3DDrago%252CV%26author%3DKovalevsky%252CA%26author%3DDajnowicz%252CS"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="71."><p class="c-article-references__text" id="ref-CR71">Casasnovas, R. et al. C-H Activation in Pyridoxal-5 ’-phosphate Schiff bases: the role of the imine nitrogen. A combined experimental and computational study. <i>J. Phys. Chem. B</i> <b>116</b>, 10665–10675 (2012).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/jp303678n" data-track-item_id="10.1021/jp303678n" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Fjp303678n" aria-label="Article reference 71" data-doi="10.1021/jp303678n">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC38XhtFWhsb%2FE?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 71">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D22845654" aria-label="PubMed reference 71">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 71" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DC-H%2520Activation%2520in%2520Pyridoxal-5%2520%25E2%2580%2599-phosphate%2520Schiff%2520bases%253A%2520the%2520role%2520of%2520the%2520imine%2520nitrogen.%2520A%2520combined%2520experimental%2520and%2520computational%2520study%26journal%3DJ.%2520Phys.%2520Chem.%2520B%26doi%3D10.1021%252Fjp303678n%26volume%3D116%26pages%3D10665-10675%26publication_year%3D2012%26author%3DCasasnovas%252CR"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="72."><p class="c-article-references__text" id="ref-CR72">Rajaram, V. et al. Structure determination and biochemical studies on <i>Bacillus</i> stearothermophilus E53Q serine hydroxymethyltransferase and its complexes provide insights on function and enzyme memory. <i>FEBS J.</i> <b>274</b>, 4148–4160 (2007).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1111/j.1742-4658.2007.05943.x" data-track-item_id="10.1111/j.1742-4658.2007.05943.x" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1111%252Fj.1742-4658.2007.05943.x" aria-label="Article reference 72" data-doi="10.1111/j.1742-4658.2007.05943.x">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD2sXhtVSmt7vO?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 72">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D17651438" aria-label="PubMed reference 72">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 72" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DStructure%2520determination%2520and%2520biochemical%2520studies%2520on%2520Bacillus%2520stearothermophilus%2520E53Q%2520serine%2520hydroxymethyltransferase%2520and%2520its%2520complexes%2520provide%2520insights%2520on%2520function%2520and%2520enzyme%2520memory%26journal%3DFEBS%2520J.%26doi%3D10.1111%252Fj.1742-4658.2007.05943.x%26volume%3D274%26pages%3D4148-4160%26publication_year%3D2007%26author%3DRajaram%252CV"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="73."><p class="c-article-references__text" id="ref-CR73">Shcheynikov, N. et al. Intracellular Cl- as a signaling ion that potently regulates Na+/HCO3- transporters. <i>Proc. Natl Acad. Sci. USA</i> <b>112</b>, E329–E337 (2015).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1073/pnas.1415673112" data-track-item_id="10.1073/pnas.1415673112" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1073%252Fpnas.1415673112" aria-label="Article reference 73" data-doi="10.1073/pnas.1415673112">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC2MXjtFCqtA%3D%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 73">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D25561556" aria-label="PubMed reference 73">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4311818" aria-label="PubMed Central reference 73">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 73" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DIntracellular%2520Cl-%2520as%2520a%2520signaling%2520ion%2520that%2520potently%2520regulates%2520Na%252B%252FHCO3-%2520transporters%26journal%3DProc.%2520Natl%2520Acad.%2520Sci.%2520USA%26doi%3D10.1073%252Fpnas.1415673112%26volume%3D112%26pages%3DE329-E337%26publication_year%3D2015%26author%3DShcheynikov%252CN"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="74."><p class="c-article-references__text" id="ref-CR74">Jahn, S. C., Rowland-Faux, L., Stacpoole, P. W. & James, M. O. Chloride concentrations in human hepatic cytosol and mitochondria are a function of age. <i>Biochem. Biophys. Res Commun.</i> <b>459</b>, 463–468 (2015).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.bbrc.2015.02.128" data-track-item_id="10.1016/j.bbrc.2015.02.128" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fj.bbrc.2015.02.128" aria-label="Article reference 74" data-doi="10.1016/j.bbrc.2015.02.128">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC2MXktFKjt70%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 74">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D25748576" aria-label="PubMed reference 74">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4380591" aria-label="PubMed Central reference 74">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 74" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DChloride%2520concentrations%2520in%2520human%2520hepatic%2520cytosol%2520and%2520mitochondria%2520are%2520a%2520function%2520of%2520age%26journal%3DBiochem.%2520Biophys.%2520Res%2520Commun.%26doi%3D10.1016%252Fj.bbrc.2015.02.128%26volume%3D459%26pages%3D463-468%26publication_year%3D2015%26author%3DJahn%252CSC%26author%3DRowland-Faux%252CL%26author%3DStacpoole%252CPW%26author%3DJames%252CMO"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="75."><p class="c-article-references__text" id="ref-CR75">Eliot, A. C. & Kirsch, J. F. Modulation of the internal aldimine pK(a)’s of 1-aminocyclopropane-1-carboxylate synthase and aspartate arninotransferase by specific active site residues. <i>Biochemistry</i> <b>41</b>, 3836–3842 (2002).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/bi016084l" data-track-item_id="10.1021/bi016084l" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Fbi016084l" aria-label="Article reference 75" data-doi="10.1021/bi016084l">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD38XhsVCiu74%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 75">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D11888303" aria-label="PubMed reference 75">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 75" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DModulation%2520of%2520the%2520internal%2520aldimine%2520pK%2528a%2529%25E2%2580%2599s%2520of%25201-aminocyclopropane-1-carboxylate%2520synthase%2520and%2520aspartate%2520arninotransferase%2520by%2520specific%2520active%2520site%2520residues%26journal%3DBiochemistry%26doi%3D10.1021%252Fbi016084l%26volume%3D41%26pages%3D3836-3842%26publication_year%3D2002%26author%3DEliot%252CAC%26author%3DKirsch%252CJF"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="76."><p class="c-article-references__text" id="ref-CR76">Ruszkowski, M. et al. Structural basis of methotrexate and pemetrexed action on serine hydroxymethyltransferases revealed using plant models. <i>Sci. Rep.-UK</i> <b>9</b>, 19614 (2019).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1038/s41598-019-56043-4" data-track-item_id="10.1038/s41598-019-56043-4" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1038%252Fs41598-019-56043-4" aria-label="Article reference 76" data-doi="10.1038/s41598-019-56043-4">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3cXmtF2rsQ%3D%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 76">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 76" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DStructural%2520basis%2520of%2520methotrexate%2520and%2520pemetrexed%2520action%2520on%2520serine%2520hydroxymethyltransferases%2520revealed%2520using%2520plant%2520models%26journal%3DSci.%2520Rep.-UK%26doi%3D10.1038%252Fs41598-019-56043-4%26volume%3D9%26publication_year%3D2019%26author%3DRuszkowski%252CM"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="77."><p class="c-article-references__text" id="ref-CR77">Makino, Y. et al. Serine hydroxymethyltransferase as a potential target of antibacterial agents acting synergistically with one-carbon metabolism-related inhibitors. <i>Commun. Biol.</i> <b>5</b>, 619 (2022).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1038/s42003-022-03555-x" data-track-item_id="10.1038/s42003-022-03555-x" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1038%252Fs42003-022-03555-x" aria-label="Article reference 77" data-doi="10.1038/s42003-022-03555-x">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB38XhvVGnu7vK?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 77">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D35739195" aria-label="PubMed reference 77">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9223267" aria-label="PubMed Central reference 77">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 77" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DSerine%2520hydroxymethyltransferase%2520as%2520a%2520potential%2520target%2520of%2520antibacterial%2520agents%2520acting%2520synergistically%2520with%2520one-carbon%2520metabolism-related%2520inhibitors%26journal%3DCommun.%2520Biol.%26doi%3D10.1038%252Fs42003-022-03555-x%26volume%3D5%26publication_year%3D2022%26author%3DMakino%252CY"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="78."><p class="c-article-references__text" id="ref-CR78">Chitnumsub, P. et al. Structures of Plasmodium vivax serine hydroxymethyltransferase: implications for ligand-binding specificity and functional control. <i>Acta Crystallogr D.</i> <b>70</b>, 3177–3186 (2014).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S1399004714023128" data-track-item_id="10.1107/S1399004714023128" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS1399004714023128" aria-label="Article reference 78" data-doi="10.1107/S1399004714023128">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC2cXitVegtbvJ?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 78">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D25478836" aria-label="PubMed reference 78">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4257618" aria-label="PubMed Central reference 78">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 78" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DStructures%2520of%2520Plasmodium%2520vivax%2520serine%2520hydroxymethyltransferase%253A%2520implications%2520for%2520ligand-binding%2520specificity%2520and%2520functional%2520control%26journal%3DActa%2520Crystallogr%2520D.%26doi%3D10.1107%252FS1399004714023128%26volume%3D70%26pages%3D3177-3186%26publication_year%3D2014%26author%3DChitnumsub%252CP"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="79."><p class="c-article-references__text" id="ref-CR79">Ruszkowski, M., Sekula, B., Ruszkowska, A. & Dauter, Z. Chloroplastic serine hydroxymethyltransferase from medicago truncatula: a structural characterization. <i>Front Plant Sci.</i> <b>9</b>, 584 (2018).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.3389/fpls.2018.00584" data-track-item_id="10.3389/fpls.2018.00584" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.3389%252Ffpls.2018.00584" aria-label="Article reference 79" data-doi="10.3389/fpls.2018.00584">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D29868052" aria-label="PubMed reference 79">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5958214" aria-label="PubMed Central reference 79">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 79" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DChloroplastic%2520serine%2520hydroxymethyltransferase%2520from%2520medicago%2520truncatula%253A%2520a%2520structural%2520characterization%26journal%3DFront%2520Plant%2520Sci.%26doi%3D10.3389%252Ffpls.2018.00584%26volume%3D9%26publication_year%3D2018%26author%3DRuszkowski%252CM%26author%3DSekula%252CB%26author%3DRuszkowska%252CA%26author%3DDauter%252CZ"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="80."><p class="c-article-references__text" id="ref-CR80">Gerlits, O. O., Coates, L., Woods, R. J. & Kovalevsky, A. Mannobiose binding induces changes in hydrogen bonding and protonation states of acidic residues in concanavalin a as revealed by neutron crystallography. <i>Biochemistry</i> <b>56</b>, 4747–4750 (2017).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/acs.biochem.7b00654" data-track-item_id="10.1021/acs.biochem.7b00654" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Facs.biochem.7b00654" aria-label="Article reference 80" data-doi="10.1021/acs.biochem.7b00654">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC2sXhtl2it7nN?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 80">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D28846383" aria-label="PubMed reference 80">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 80" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DMannobiose%2520binding%2520induces%2520changes%2520in%2520hydrogen%2520bonding%2520and%2520protonation%2520states%2520of%2520acidic%2520residues%2520in%2520concanavalin%2520a%2520as%2520revealed%2520by%2520neutron%2520crystallography%26journal%3DBiochemistry%26doi%3D10.1021%252Facs.biochem.7b00654%26volume%3D56%26pages%3D4747-4750%26publication_year%3D2017%26author%3DGerlits%252COO%26author%3DCoates%252CL%26author%3DWoods%252CRJ%26author%3DKovalevsky%252CA"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="81."><p class="c-article-references__text" id="ref-CR81">Gerlits, O. et al. Room temperature neutron crystallography of drug resistant HIV-1 protease uncovers limitations of X-ray structural analysis at 100 K. <i>J. Med. Chem.</i> <b>60</b>, 2018–2025 (2017).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/acs.jmedchem.6b01767" data-track-item_id="10.1021/acs.jmedchem.6b01767" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Facs.jmedchem.6b01767" aria-label="Article reference 81" data-doi="10.1021/acs.jmedchem.6b01767">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC2sXis1yit74%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 81">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D28195728" aria-label="PubMed reference 81">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5644340" aria-label="PubMed Central reference 81">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 81" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DRoom%2520temperature%2520neutron%2520crystallography%2520of%2520drug%2520resistant%2520HIV-1%2520protease%2520uncovers%2520limitations%2520of%2520X-ray%2520structural%2520analysis%2520at%2520100%2520K%26journal%3DJ.%2520Med.%2520Chem.%26doi%3D10.1021%252Facs.jmedchem.6b01767%26volume%3D60%26pages%3D2018-2025%26publication_year%3D2017%26author%3DGerlits%252CO"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="82."><p class="c-article-references__text" id="ref-CR82">Contestabile, R. et al. Role of tyrosine 65 in the mechanism of serine hydroxymethyltransferase. <i>Biochemistry</i> <b>39</b>, 7492–7500 (2000).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/bi000032z" data-track-item_id="10.1021/bi000032z" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Fbi000032z" aria-label="Article reference 82" data-doi="10.1021/bi000032z">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD3cXjsFOrsLw%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 82">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D10858298" aria-label="PubMed reference 82">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 82" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DRole%2520of%2520tyrosine%252065%2520in%2520the%2520mechanism%2520of%2520serine%2520hydroxymethyltransferase%26journal%3DBiochemistry%26doi%3D10.1021%252Fbi000032z%26volume%3D39%26pages%3D7492-7500%26publication_year%3D2000%26author%3DContestabile%252CR"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="83."><p class="c-article-references__text" id="ref-CR83">Chiba, Y. et al. Mechanism for folate-independent aldolase reaction catalyzed by serine hydroxymethyltransferase. <i>FEBS J.</i> <b>279</b>, 504–514 (2012).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1111/j.1742-4658.2011.08443.x" data-track-item_id="10.1111/j.1742-4658.2011.08443.x" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1111%252Fj.1742-4658.2011.08443.x" aria-label="Article reference 83" data-doi="10.1111/j.1742-4658.2011.08443.x">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC38Xhs1ymtbo%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 83">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D22141341" aria-label="PubMed reference 83">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 83" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DMechanism%2520for%2520folate-independent%2520aldolase%2520reaction%2520catalyzed%2520by%2520serine%2520hydroxymethyltransferase%26journal%3DFEBS%2520J.%26doi%3D10.1111%252Fj.1742-4658.2011.08443.x%26volume%3D279%26pages%3D504-514%26publication_year%3D2012%26author%3DChiba%252CY"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="84."><p class="c-article-references__text" id="ref-CR84">Soniya, K. & Chandra, A. Free energy landscape and proton transfer pathways of the transimination reaction at the active site of the serine hydroxymethyltransferase enzyme in aqueous medium. <i>J. Phys. Chem. B</i> <b>125</b>, 11848–11856 (2021).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1021/acs.jpcb.1c05864" data-track-item_id="10.1021/acs.jpcb.1c05864" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1021%252Facs.jpcb.1c05864" aria-label="Article reference 84" data-doi="10.1021/acs.jpcb.1c05864">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXitlSjsb%2FJ?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 84">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D34696588" aria-label="PubMed reference 84">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 84" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DFree%2520energy%2520landscape%2520and%2520proton%2520transfer%2520pathways%2520of%2520the%2520transimination%2520reaction%2520at%2520the%2520active%2520site%2520of%2520the%2520serine%2520hydroxymethyltransferase%2520enzyme%2520in%2520aqueous%2520medium%26journal%3DJ.%2520Phys.%2520Chem.%2520B%26doi%3D10.1021%252Facs.jpcb.1c05864%26volume%3D125%26pages%3D11848-11856%26publication_year%3D2021%26author%3DSoniya%252CK%26author%3DChandra%252CA"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="85."><p class="c-article-references__text" id="ref-CR85">Di Salvo, M. L. et al. Structure-based mechanism for early PLP-mediated steps of rabbit cytosolic serine hydroxymethyltransferase reaction. <i>Biomed. Res. Int.</i> <b>2013</b>, 458571 (2013).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1155/2013/458571" data-track-item_id="10.1155/2013/458571" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1155%252F2013%252F458571" aria-label="Article reference 85" data-doi="10.1155/2013/458571">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D23956983" aria-label="PubMed reference 85">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3728543" aria-label="PubMed Central reference 85">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 85" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DStructure-based%2520mechanism%2520for%2520early%2520PLP-mediated%2520steps%2520of%2520rabbit%2520cytosolic%2520serine%2520hydroxymethyltransferase%2520reaction%26journal%3DBiomed.%2520Res.%2520Int.%26doi%3D10.1155%252F2013%252F458571%26volume%3D2013%26publication_year%3D2013%26author%3DSalvo%252CML"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="86."><p class="c-article-references__text" id="ref-CR86">Talwar, R., Jagath, J. R., Rao, N. A. & Savithri, H. S. His230 of serine hydroxymethyltransferase facilitates the proton abstraction step in catalysis. <i>Eur. J. Biochem.</i> <b>267</b>, 1441–1446 (2000).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1046/j.1432-1327.2000.01142.x" data-track-item_id="10.1046/j.1432-1327.2000.01142.x" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1046%252Fj.1432-1327.2000.01142.x" aria-label="Article reference 86" data-doi="10.1046/j.1432-1327.2000.01142.x">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD3cXhvVagsL4%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 86">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D10691982" aria-label="PubMed reference 86">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 86" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DHis230%2520of%2520serine%2520hydroxymethyltransferase%2520facilitates%2520the%2520proton%2520abstraction%2520step%2520in%2520catalysis%26journal%3DEur.%2520J.%2520Biochem.%26doi%3D10.1046%252Fj.1432-1327.2000.01142.x%26volume%3D267%26pages%3D1441-1446%26publication_year%3D2000%26author%3DTalwar%252CR%26author%3DJagath%252CJR%26author%3DRao%252CNA%26author%3DSavithri%252CHS"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="87."><p class="c-article-references__text" id="ref-CR87">Rao, J. V. K., Prakash, V., Rao, N. A. & Savithri, H. S. The role of Glu74 and Tyr82 in the reaction catalyzed by sheep liver cytosolic serine hydroxymethyltransferase. <i>Eur. J. Biochem</i> <b>267</b>, 5967–5976 (2000).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1046/j.1432-1327.2000.01667.x" data-track-item_id="10.1046/j.1432-1327.2000.01667.x" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1046%252Fj.1432-1327.2000.01667.x" aria-label="Article reference 87" data-doi="10.1046/j.1432-1327.2000.01667.x">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD3cXnt1Smtrw%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 87">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D10998057" aria-label="PubMed reference 87">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 87" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DThe%2520role%2520of%2520Glu74%2520and%2520Tyr82%2520in%2520the%2520reaction%2520catalyzed%2520by%2520sheep%2520liver%2520cytosolic%2520serine%2520hydroxymethyltransferase%26journal%3DEur.%2520J.%2520Biochem%26doi%3D10.1046%252Fj.1432-1327.2000.01667.x%26volume%3D267%26pages%3D5967-5976%26publication_year%3D2000%26author%3DRao%252CJVK%26author%3DPrakash%252CV%26author%3DRao%252CNA%26author%3DSavithri%252CHS"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="88."><p class="c-article-references__text" id="ref-CR88">Blakeley, M. P. et al. Neutron macromolecular crystallography with LADI-III. <i>Acta Crystallogr. D. Biol. Crystallogr.</i> <b>66</b>, 1198–1205 (2010).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444910019797" data-track-item_id="10.1107/S0907444910019797" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444910019797" aria-label="Article reference 88" data-doi="10.1107/S0907444910019797">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC3cXhtlKlsrnJ?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 88">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D21041937" aria-label="PubMed reference 88">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 88" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DNeutron%2520macromolecular%2520crystallography%2520with%2520LADI-III%26journal%3DActa%2520Crystallogr.%2520D.%2520Biol.%2520Crystallogr.%26doi%3D10.1107%252FS0907444910019797%26volume%3D66%26pages%3D1198-1205%26publication_year%3D2010%26author%3DBlakeley%252CMP"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="89."><p class="c-article-references__text" id="ref-CR89">Meilleur, F. et al. The IMAGINE instrument: first neutron protein structure and new capabilities for neutron macromolecular crystallography. <i>Acta Crystallogr. D. Biol. Crystallogr.</i> <b>69</b>, 2157–2160 (2013).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444913019604" data-track-item_id="10.1107/S0907444913019604" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444913019604" aria-label="Article reference 89" data-doi="10.1107/S0907444913019604">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC3sXhsFOmtrbI?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 89">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D24100333" aria-label="PubMed reference 89">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 89" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DThe%2520IMAGINE%2520instrument%253A%2520first%2520neutron%2520protein%2520structure%2520and%2520new%2520capabilities%2520for%2520neutron%2520macromolecular%2520crystallography%26journal%3DActa%2520Crystallogr.%2520D.%2520Biol.%2520Crystallogr.%26doi%3D10.1107%252FS0907444913019604%26volume%3D69%26pages%3D2157-2160%26publication_year%3D2013%26author%3DMeilleur%252CF"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="90."><p class="c-article-references__text" id="ref-CR90">Meilleur, F., Coates, L., Cuneo, M. J., Kovalevsky, A. & Myles, D. A. A. The neutron macromolecular crystallography instruments at oak ridge national laboratory: advances, challenges, and opportunities. <i>Crystals</i> <b>8</b>, 388 (2018).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.3390/cryst8100388" data-track-item_id="10.3390/cryst8100388" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.3390%252Fcryst8100388" aria-label="Article reference 90" data-doi="10.3390/cryst8100388">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 90" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DThe%2520neutron%2520macromolecular%2520crystallography%2520instruments%2520at%2520oak%2520ridge%2520national%2520laboratory%253A%2520advances%252C%2520challenges%252C%2520and%2520opportunities%26journal%3DCrystals%26doi%3D10.3390%252Fcryst8100388%26volume%3D8%26publication_year%3D2018%26author%3DMeilleur%252CF%26author%3DCoates%252CL%26author%3DCuneo%252CMJ%26author%3DKovalevsky%252CA%26author%3DMyles%252CDAA"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="91."><p class="c-article-references__text" id="ref-CR91">Schroder, G. C., O’Dell, W. B., Myles, D. A. A., Kovalevsky, A. & Meilleur, F. IMAGINE: neutrons reveal enzyme chemistry. <i>Acta Crystallogr. D. Struct. Biol.</i> <b>74</b>, 778–786 (2018).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S2059798318001626" data-track-item_id="10.1107/S2059798318001626" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS2059798318001626" aria-label="Article reference 91" data-doi="10.1107/S2059798318001626">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC1cXhsVGisb7N?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 91">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D30082513" aria-label="PubMed reference 91">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 91" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DIMAGINE%253A%2520neutrons%2520reveal%2520enzyme%2520chemistry%26journal%3DActa%2520Crystallogr.%2520D.%2520Struct.%2520Biol.%26doi%3D10.1107%252FS2059798318001626%26volume%3D74%26pages%3D778-786%26publication_year%3D2018%26author%3DSchroder%252CGC%26author%3DO%25E2%2580%2599Dell%252CWB%26author%3DMyles%252CDAA%26author%3DKovalevsky%252CA%26author%3DMeilleur%252CF"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="92."><p class="c-article-references__text" id="ref-CR92">Meilleur, F., Kovalevsky, A. & Myles, D. A. A. IMAGINE: The neutron protein crystallography beamline at the high flux isotope reactor. <i>Methods Enzymol.</i> <b>634</b>, 69–85 (2020).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/bs.mie.2019.11.016" data-track-item_id="10.1016/bs.mie.2019.11.016" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fbs.mie.2019.11.016" aria-label="Article reference 92" data-doi="10.1016/bs.mie.2019.11.016">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXktFansrY%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 92">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D32093843" aria-label="PubMed reference 92">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 92" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DIMAGINE%253A%2520The%2520neutron%2520protein%2520crystallography%2520beamline%2520at%2520the%2520high%2520flux%2520isotope%2520reactor%26journal%3DMethods%2520Enzymol.%26doi%3D10.1016%252Fbs.mie.2019.11.016%26volume%3D634%26pages%3D69-85%26publication_year%3D2020%26author%3DMeilleur%252CF%26author%3DKovalevsky%252CA%26author%3DMyles%252CDAA"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="93."><p class="c-article-references__text" id="ref-CR93">Campbell, J. W. Lauegen, an X-windows-based program for the processing of Laue X-Ray-diffraction data. <i>J. Appl. Crystallogr.</i> <b>28</b>, 228–236 (1995).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S002188989400991X" data-track-item_id="10.1107/S002188989400991X" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS002188989400991X" aria-label="Article reference 93" data-doi="10.1107/S002188989400991X">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaK2MXltVektbY%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 93">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 93" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DLauegen%252C%2520an%2520X-windows-based%2520program%2520for%2520the%2520processing%2520of%2520Laue%2520X-Ray-diffraction%2520data%26journal%3DJ.%2520Appl.%2520Crystallogr.%26doi%3D10.1107%252FS002188989400991X%26volume%3D28%26pages%3D228-236%26publication_year%3D1995%26author%3DCampbell%252CJW"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="94."><p class="c-article-references__text" id="ref-CR94">Campbell, J. W., Hao, Q., Harding, M. M., Nguti, N. D. & Wilkinson, C. LAUEGEN version 6.0 and INTLDM. <i>J. Appl. Crystallogr.</i> <b>31</b>, 496–502 (1998).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0021889897016683" data-track-item_id="10.1107/S0021889897016683" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0021889897016683" aria-label="Article reference 94" data-doi="10.1107/S0021889897016683">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaK1cXltFOht7g%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 94">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 94" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DLAUEGEN%2520version%25206.0%2520and%2520INTLDM%26journal%3DJ.%2520Appl.%2520Crystallogr.%26doi%3D10.1107%252FS0021889897016683%26volume%3D31%26pages%3D496-502%26publication_year%3D1998%26author%3DCampbell%252CJW%26author%3DHao%252CQ%26author%3DHarding%252CMM%26author%3DNguti%252CND%26author%3DWilkinson%252CC"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="95."><p class="c-article-references__text" id="ref-CR95">Arzt, S., Campbell, J. W., Harding, M. M., Hao, Q. & Helliwell, J. R. LSCALE - the new normalization, scaling and absorption correction program in the Daresbury Laue software suite. <i>J. Appl. Crystallogr.</i> <b>32</b>, 554–562 (1999).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0021889898015350" data-track-item_id="10.1107/S0021889898015350" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0021889898015350" aria-label="Article reference 95" data-doi="10.1107/S0021889898015350">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaK1MXktlCruro%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 95">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 95" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DLSCALE%2520-%2520the%2520new%2520normalization%252C%2520scaling%2520and%2520absorption%2520correction%2520program%2520in%2520the%2520Daresbury%2520Laue%2520software%2520suite%26journal%3DJ.%2520Appl.%2520Crystallogr.%26doi%3D10.1107%252FS0021889898015350%26volume%3D32%26pages%3D554-562%26publication_year%3D1999%26author%3DArzt%252CS%26author%3DCampbell%252CJW%26author%3DHarding%252CMM%26author%3DHao%252CQ%26author%3DHelliwell%252CJR"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="96."><p class="c-article-references__text" id="ref-CR96">Coates, L. et al. The macromolecular neutron diffractometer MaNDi at the spallation neutron source. <i>J. Appl. Crystallogr.</i> <b>48</b>, 1302–1306 (2015).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S1600576715011243" data-track-item_id="10.1107/S1600576715011243" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS1600576715011243" aria-label="Article reference 96" data-doi="10.1107/S1600576715011243">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC2MXht1KgsLvJ?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 96">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 96" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DThe%2520macromolecular%2520neutron%2520diffractometer%2520MaNDi%2520at%2520the%2520spallation%2520neutron%2520source%26journal%3DJ.%2520Appl.%2520Crystallogr.%26doi%3D10.1107%252FS1600576715011243%26volume%3D48%26pages%3D1302-1306%26publication_year%3D2015%26author%3DCoates%252CL"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="97."><p class="c-article-references__text" id="ref-CR97">Coates, L. & Sullivan, B. The macromolecular neutron diffractometer at the spallation neutron source. <i>Method Enzymol.</i> <b>634</b>, 87–99 (2020).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/bs.mie.2019.11.020" data-track-item_id="10.1016/bs.mie.2019.11.020" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fbs.mie.2019.11.020" aria-label="Article reference 97" data-doi="10.1016/bs.mie.2019.11.020">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3MXktFans70%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 97">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 97" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DThe%2520macromolecular%2520neutron%2520diffractometer%2520at%2520the%2520spallation%2520neutron%2520source%26journal%3DMethod%2520Enzymol.%26doi%3D10.1016%252Fbs.mie.2019.11.020%26volume%3D634%26pages%3D87-99%26publication_year%3D2020%26author%3DCoates%252CL%26author%3DSullivan%252CB"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="98."><p class="c-article-references__text" id="ref-CR98">Arnold, O. et al. Mantid—Data analysis and visualization package for neutron scattering and μ SR experiments. <i>Nucl. Instrum. Methods Phys. Res. Sect. A: Accel. Spectrom. Detect. Assoc. Equip.</i> <b>764</b>, 156–166 (2014).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1016/j.nima.2014.07.029" data-track-item_id="10.1016/j.nima.2014.07.029" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1016%252Fj.nima.2014.07.029" aria-label="Article reference 98" data-doi="10.1016/j.nima.2014.07.029">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC2cXhtlGntrfL?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 98">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 98" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DMantid%25E2%2580%2594Data%2520analysis%2520and%2520visualization%2520package%2520for%2520neutron%2520scattering%2520and%2520%25CE%25BC%2520SR%2520experiments%26journal%3DNucl.%2520Instrum.%2520Methods%2520Phys.%2520Res.%2520Sect.%2520A%253A%2520Accel.%2520Spectrom.%2520Detect.%2520Assoc.%2520Equip.%26doi%3D10.1016%252Fj.nima.2014.07.029%26volume%3D764%26pages%3D156-166%26publication_year%3D2014%26author%3DArnold%252CO"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="99."><p class="c-article-references__text" id="ref-CR99">Sullivan, B. et al. Improving the accuracy and resolution of neutron crystallographic data by three-dimensional profile fitting of Bragg peaks in reciprocal space. <i>Acta Crystallogr. Sect. D.-Struct. Biol.</i> <b>74</b>, 1085–1095 (2018).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S2059798318013347" data-track-item_id="10.1107/S2059798318013347" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS2059798318013347" aria-label="Article reference 99" data-doi="10.1107/S2059798318013347">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC1cXitVOhsrvP?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 99">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 99" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DImproving%2520the%2520accuracy%2520and%2520resolution%2520of%2520neutron%2520crystallographic%2520data%2520by%2520three-dimensional%2520profile%2520fitting%2520of%2520Bragg%2520peaks%2520in%2520reciprocal%2520space%26journal%3DActa%2520Crystallogr.%2520Sect.%2520D.-Struct.%2520Biol.%26doi%3D10.1107%252FS2059798318013347%26volume%3D74%26pages%3D1085-1095%26publication_year%3D2018%26author%3DSullivan%252CB"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="100."><p class="c-article-references__text" id="ref-CR100">Helliwell, J. R. et al. The recording and analysis of synchrotron X-radiation laue diffraction photographs. <i>J. Appl. Crystallogr.</i> <b>22</b>, 483–497 (1989).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0021889889006564" data-track-item_id="10.1107/S0021889889006564" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0021889889006564" aria-label="Article reference 100" data-doi="10.1107/S0021889889006564">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DyaL1MXmsVCrtbc%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 100">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 100" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DThe%2520recording%2520and%2520analysis%2520of%2520synchrotron%2520X-radiation%2520laue%2520diffraction%2520photographs%26journal%3DJ.%2520Appl.%2520Crystallogr.%26doi%3D10.1107%252FS0021889889006564%26volume%3D22%26pages%3D483-497%26publication_year%3D1989%26author%3DHelliwell%252CJR"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="101."><p class="c-article-references__text" id="ref-CR101">Weiss, M. S. Global indicators of X-ray data quality. <i>J. Appl. Crystallogr.</i> <b>34</b>, 130–135 (2001).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0021889800018227" data-track-item_id="10.1107/S0021889800018227" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0021889800018227" aria-label="Article reference 101" data-doi="10.1107/S0021889800018227">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD3MXit1yhsLk%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 101">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 101" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DGlobal%2520indicators%2520of%2520X-ray%2520data%2520quality%26journal%3DJ.%2520Appl.%2520Crystallogr.%26doi%3D10.1107%252FS0021889800018227%26volume%3D34%26pages%3D130-135%26publication_year%3D2001%26author%3DWeiss%252CMS"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="102."><p class="c-article-references__text" id="ref-CR102">Evans, P. R. & Murshudov, G. N. How good are my data and what is the resolution? <i>Acta Crystallogr. D. Biol. Crystallogr.</i> <b>69</b>, 1204–1214 (2013).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444913000061" data-track-item_id="10.1107/S0907444913000061" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444913000061" aria-label="Article reference 102" data-doi="10.1107/S0907444913000061">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC3sXpvVejsL8%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 102">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D23793146" aria-label="PubMed reference 102">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3689523" aria-label="PubMed Central reference 102">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 102" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DHow%2520good%2520are%2520my%2520data%2520and%2520what%2520is%2520the%2520resolution%253F%26journal%3DActa%2520Crystallogr.%2520D.%2520Biol.%2520Crystallogr.%26doi%3D10.1107%252FS0907444913000061%26volume%3D69%26pages%3D1204-1214%26publication_year%3D2013%26author%3DEvans%252CPR%26author%3DMurshudov%252CGN"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="103."><p class="c-article-references__text" id="ref-CR103">Winn, M. D. et al. Overview of the CCP4 suite and current developments. <i>Acta Crystallogr. Sect. D.-Struct. Biol.</i> <b>67</b>, 235–242 (2011).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444910045749" data-track-item_id="10.1107/S0907444910045749" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444910045749" aria-label="Article reference 103" data-doi="10.1107/S0907444910045749">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC3MXktFWqt70%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 103">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 103" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DOverview%2520of%2520the%2520CCP4%2520suite%2520and%2520current%2520developments%26journal%3DActa%2520Crystallogr.%2520Sect.%2520D.-Struct.%2520Biol.%26doi%3D10.1107%252FS0907444910045749%26volume%3D67%26pages%3D235-242%26publication_year%3D2011%26author%3DWinn%252CMD"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="104."><p class="c-article-references__text" id="ref-CR104">Mccoy, A. J. et al. Phaser crystallographic software. <i>J. Appl. Crystallogr.</i> <b>40</b>, 658–674 (2007).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0021889807021206" data-track-item_id="10.1107/S0021889807021206" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0021889807021206" aria-label="Article reference 104" data-doi="10.1107/S0021889807021206">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD2sXnslWqsLk%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 104">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D19461840" aria-label="PubMed reference 104">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2483472" aria-label="PubMed Central reference 104">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 104" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DPhaser%2520crystallographic%2520software%26journal%3DJ.%2520Appl.%2520Crystallogr.%26doi%3D10.1107%252FS0021889807021206%26volume%3D40%26pages%3D658-674%26publication_year%3D2007%26author%3DMccoy%252CAJ"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="105."><p class="c-article-references__text" id="ref-CR105">Minor, W., Cymborowski, M., Otwinowski, Z. & Chruszcz, M. HKL-3000: the integration of data reduction and structure solution-from diffraction images to an initial model in minutes. <i>Acta Crystallogr. D. Biol. Crystallogr.</i> <b>62</b>, 859–866 (2006).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444906019949" data-track-item_id="10.1107/S0907444906019949" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444906019949" aria-label="Article reference 105" data-doi="10.1107/S0907444906019949">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D16855301" aria-label="PubMed reference 105">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 105" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DHKL-3000%253A%2520the%2520integration%2520of%2520data%2520reduction%2520and%2520structure%2520solution-from%2520diffraction%2520images%2520to%2520an%2520initial%2520model%2520in%2520minutes%26journal%3DActa%2520Crystallogr.%2520D.%2520Biol.%2520Crystallogr.%26doi%3D10.1107%252FS0907444906019949%26volume%3D62%26pages%3D859-866%26publication_year%3D2006%26author%3DMinor%252CW%26author%3DCymborowski%252CM%26author%3DOtwinowski%252CZ%26author%3DChruszcz%252CM"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="106."><p class="c-article-references__text" id="ref-CR106">Adams, P. D. et al. PHENIX: a comprehensive Python-based system for macromolecular structure solution. <i>Acta Crystallogr. D. Biol. Crystallogr.</i> <b>66</b>, 213–221 (2010).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444909052925" data-track-item_id="10.1107/S0907444909052925" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444909052925" aria-label="Article reference 106" data-doi="10.1107/S0907444909052925">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC3cXhs1Sisbc%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 106">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D20124702" aria-label="PubMed reference 106">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2815670" aria-label="PubMed Central reference 106">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 106" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DPHENIX%253A%2520a%2520comprehensive%2520Python-based%2520system%2520for%2520macromolecular%2520structure%2520solution%26journal%3DActa%2520Crystallogr.%2520D.%2520Biol.%2520Crystallogr.%26doi%3D10.1107%252FS0907444909052925%26volume%3D66%26pages%3D213-221%26publication_year%3D2010%26author%3DAdams%252CPD"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="107."><p class="c-article-references__text" id="ref-CR107">Liebschner, D. et al. Macromolecular structure determination using X-rays, neutrons and electrons: recent developments in Phenix. <i>Acta Crystallogr. Sect. D.-Struct. Biol.</i> <b>75</b>, 861–877 (2019).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S2059798319011471" data-track-item_id="10.1107/S2059798319011471" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS2059798319011471" aria-label="Article reference 107" data-doi="10.1107/S2059798319011471">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC1MXhvFWkurrO?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 107">CAS</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 107" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DMacromolecular%2520structure%2520determination%2520using%2520X-rays%252C%2520neutrons%2520and%2520electrons%253A%2520recent%2520developments%2520in%2520Phenix%26journal%3DActa%2520Crystallogr.%2520Sect.%2520D.-Struct.%2520Biol.%26doi%3D10.1107%252FS2059798319011471%26volume%3D75%26pages%3D861-877%26publication_year%3D2019%26author%3DLiebschner%252CD"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="108."><p class="c-article-references__text" id="ref-CR108">Emsley, P. & Cowtan, K. Coot: model-building tools for molecular graphics. <i>Acta Crystallogr. Sect. D.-Struct. Biol.</i> <b>60</b>, 2126–2132 (2004).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444904019158" data-track-item_id="10.1107/S0907444904019158" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444904019158" aria-label="Article reference 108" data-doi="10.1107/S0907444904019158">Article</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 108" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DCoot%253A%2520model-building%2520tools%2520for%2520molecular%2520graphics%26journal%3DActa%2520Crystallogr.%2520Sect.%2520D.-Struct.%2520Biol.%26doi%3D10.1107%252FS0907444904019158%26volume%3D60%26pages%3D2126-2132%26publication_year%3D2004%26author%3DEmsley%252CP%26author%3DCowtan%252CK"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="109."><p class="c-article-references__text" id="ref-CR109">Emsley, P., Lohkamp, B., Scott, W. G. & Cowtan, K. Features and development of Coot. <i>Acta Crystallogr D. Biol. Crystallogr</i> <b>66</b>, 486–501 (2010).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444910007493" data-track-item_id="10.1107/S0907444910007493" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444910007493" aria-label="Article reference 109" data-doi="10.1107/S0907444910007493">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC3cXksFKisb8%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 109">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D20383002" aria-label="PubMed reference 109">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2852313" aria-label="PubMed Central reference 109">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 109" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DFeatures%2520and%2520development%2520of%2520Coot%26journal%3DActa%2520Crystallogr%2520D.%2520Biol.%2520Crystallogr%26doi%3D10.1107%252FS0907444910007493%26volume%3D66%26pages%3D486-501%26publication_year%3D2010%26author%3DEmsley%252CP%26author%3DLohkamp%252CB%26author%3DScott%252CWG%26author%3DCowtan%252CK"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="110."><p class="c-article-references__text" id="ref-CR110">Casanal, A., Lohkamp, B. & Emsley, P. Current developments in Coot for macromolecular model building of Electron Cryo-microscopy and Crystallographic Data. <i>Protein Sci.</i> <b>29</b>, 1069–1078 (2020).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1002/pro.3791" data-track-item_id="10.1002/pro.3791" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1002%252Fpro.3791" aria-label="Article reference 110" data-doi="10.1002/pro.3791">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BB3cXjvFyrtrw%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 110">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D31730249" aria-label="PubMed reference 110">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7096722" aria-label="PubMed Central reference 110">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 110" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DCurrent%2520developments%2520in%2520Coot%2520for%2520macromolecular%2520model%2520building%2520of%2520Electron%2520Cryo-microscopy%2520and%2520Crystallographic%2520Data%26journal%3DProtein%2520Sci.%26doi%3D10.1002%252Fpro.3791%26volume%3D29%26pages%3D1069-1078%26publication_year%3D2020%26author%3DCasanal%252CA%26author%3DLohkamp%252CB%26author%3DEmsley%252CP"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="111."><p class="c-article-references__text" id="ref-CR111">Chen, V. B. et al. MolProbity: all-atom structure validation for macromolecular crystallography. <i>Acta Crystallogr D. Biol. Crystallogr</i> <b>66</b>, 12–21 (2010).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444909042073" data-track-item_id="10.1107/S0907444909042073" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444909042073" aria-label="Article reference 111" data-doi="10.1107/S0907444909042073">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BC3cXit1Kktg%3D%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 111">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D20057044" aria-label="PubMed reference 111">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 111" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DMolProbity%253A%2520all-atom%2520structure%2520validation%2520for%2520macromolecular%2520crystallography%26journal%3DActa%2520Crystallogr%2520D.%2520Biol.%2520Crystallogr%26doi%3D10.1107%252FS0907444909042073%26volume%3D66%26pages%3D12-21%26publication_year%3D2010%26author%3DChen%252CVB"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="112."><p class="c-article-references__text" id="ref-CR112">Moriarty, N. W., Grosse-Kunstleve, R. W. & Adams, P. D. Electronic ligand builder and optimization workbench (eLBOW): a tool for ligand coordinate and restraint generation. <i>Acta Crystallogr D. Biol. Crystallogr</i> <b>65</b>, 1074–1080 (2009).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444909029436" data-track-item_id="10.1107/S0907444909029436" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444909029436" aria-label="Article reference 112" data-doi="10.1107/S0907444909029436">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD1MXhtFKnsLnN?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 112">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D19770504" aria-label="PubMed reference 112">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2748967" aria-label="PubMed Central reference 112">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 112" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DElectronic%2520ligand%2520builder%2520and%2520optimization%2520workbench%2520%2528eLBOW%2529%253A%2520a%2520tool%2520for%2520ligand%2520coordinate%2520and%2520restraint%2520generation%26journal%3DActa%2520Crystallogr%2520D.%2520Biol.%2520Crystallogr%26doi%3D10.1107%252FS0907444909029436%26volume%3D65%26pages%3D1074-1080%26publication_year%3D2009%26author%3DMoriarty%252CNW%26author%3DGrosse-Kunstleve%252CRW%26author%3DAdams%252CPD"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="113."><p class="c-article-references__text" id="ref-CR113">Gaussian 16 Rev. A.03 (Gaussian Inc., Wallingford, CT, 2016).</p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="114."><p class="c-article-references__text" id="ref-CR114">Mustyakimov, M. & Langan, P. nCNS: an open source distribution patch for CNS for macromolecular structure refinement. Ver. 1.0.8. (Los Alamos National Laboratory, Los Alamos, NM, 2007).</p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="115."><p class="c-article-references__text" id="ref-CR115">Adams, P. D., Mustyakimov, M., Afonine, P. V. & Langan, P. Generalized X-ray and neutron crystallographic analysis: more accurate and complete structures for biological macromolecules. <i>Acta Crystallogr. D. Biol. Crystallogr.</i> <b>65</b>, 567–573 (2009).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444909011548" data-track-item_id="10.1107/S0907444909011548" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444909011548" aria-label="Article reference 115" data-doi="10.1107/S0907444909011548">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD1MXmsVGjsbw%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 115">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D19465771" aria-label="PubMed reference 115">PubMed</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed central reference" data-track-action="pubmed central reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2685734" aria-label="PubMed Central reference 115">PubMed Central</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 115" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DGeneralized%2520X-ray%2520and%2520neutron%2520crystallographic%2520analysis%253A%2520more%2520accurate%2520and%2520complete%2520structures%2520for%2520biological%2520macromolecules%26journal%3DActa%2520Crystallogr.%2520D.%2520Biol.%2520Crystallogr.%26doi%3D10.1107%252FS0907444909011548%26volume%3D65%26pages%3D567-573%26publication_year%3D2009%26author%3DAdams%252CPD%26author%3DMustyakimov%252CM%26author%3DAfonine%252CPV%26author%3DLangan%252CP"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="116."><p class="c-article-references__text" id="ref-CR116">Brunger, A. T. et al. Crystallography & NMR system: a new software suite for macromolecular structure determination. <i>Acta Crystallogr. D.</i> <b>54</b>, 905–921 (1998).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1107/S0907444998003254" data-track-item_id="10.1107/S0907444998003254" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1107%252FS0907444998003254" aria-label="Article reference 116" data-doi="10.1107/S0907444998003254">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:STN:280:DyaK1cvjslKhsw%3D%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 116">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D9757107" aria-label="PubMed reference 116">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 116" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DCrystallography%2520%2526%2520NMR%2520system%253A%2520a%2520new%2520software%2520suite%2520for%2520macromolecular%2520structure%2520determination%26journal%3DActa%2520Crystallogr.%2520D.%26doi%3D10.1107%252FS0907444998003254%26volume%3D54%26pages%3D905-921%26publication_year%3D1998%26author%3DBrunger%252CAT"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="117."><p class="c-article-references__text" id="ref-CR117">Weigend, F. & Ahlrichs, R. Balanced basis sets of split valence, triple zeta valence and quadruple zeta valence quality for H to Rn: design and assessment of accuracy. <i>Phys. Chem. Chem. Phys.</i> <b>7</b>, 3297–3305 (2005).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1039/b508541a" data-track-item_id="10.1039/b508541a" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1039%252Fb508541a" aria-label="Article reference 117" data-doi="10.1039/b508541a">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD2MXpsFWgu7o%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 117">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D16240044" aria-label="PubMed reference 117">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 117" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DBalanced%2520basis%2520sets%2520of%2520split%2520valence%252C%2520triple%2520zeta%2520valence%2520and%2520quadruple%2520zeta%2520valence%2520quality%2520for%2520H%2520to%2520Rn%253A%2520design%2520and%2520assessment%2520of%2520accuracy%26journal%3DPhys.%2520Chem.%2520Chem.%2520Phys.%26doi%3D10.1039%252Fb508541a%26volume%3D7%26pages%3D3297-3305%26publication_year%3D2005%26author%3DWeigend%252CF%26author%3DAhlrichs%252CR"> Google Scholar</a> </p></li> <li class="c-article-references__item js-c-reading-companion-references-item" data-counter="118."><p class="c-article-references__text" id="ref-CR118">Weigend, F. Accurate Coulomb-fitting basis sets for H to Rn. <i>Phys. Chem. Chem. Phys.</i> <b>8</b>, 1057–1065 (2006).</p><p class="c-article-references__links u-hide-print"><a data-track="click_references" rel="nofollow noopener" data-track-label="10.1039/b515623h" data-track-item_id="10.1039/b515623h" data-track-value="article reference" data-track-action="article reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://doi.org/10.1039%252Fb515623h" aria-label="Article reference 118" data-doi="10.1039/b515623h">Article</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="cas reference" data-track-action="cas reference" href="https://www-nature-com.translate.goog/articles/cas-redirect/1:CAS:528:DC%2BD28Xhs12ntrc%3D?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto" aria-label="CAS reference 118">CAS</a> <a data-track="click_references" rel="nofollow noopener" data-track-label="link" data-track-item_id="link" data-track-value="pubmed reference" data-track-action="pubmed reference" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd%3DRetrieve%26db%3DPubMed%26dopt%3DAbstract%26list_uids%3D16633586" aria-label="PubMed reference 118">PubMed</a> <a data-track="click_references" data-track-action="google scholar reference" data-track-value="google scholar reference" data-track-label="link" data-track-item_id="link" rel="nofollow noopener" aria-label="Google Scholar reference 118" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=http://scholar.google.com/scholar_lookup?%26title%3DAccurate%2520Coulomb-fitting%2520basis%2520sets%2520for%2520H%2520to%2520Rn%26journal%3DPhys.%2520Chem.%2520Chem.%2520Phys.%26doi%3D10.1039%252Fb515623h%26volume%3D8%26pages%3D1057-1065%26publication_year%3D2006%26author%3DWeigend%252CF"> Google Scholar</a> </p></li> </ol> <p class="c-article-references__download u-hide-print"><a data-track="click" data-track-action="download citation references" data-track-label="link" rel="nofollow" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://citation-needed.springer.com/v2/references/10.1038/s42004-023-00964-9?format%3Drefman%26flavour%3Dreferences">Download references <svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"> <use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-download-medium" /> </svg></a></p> </div> </div> </div> </section> </div> <section data-title="Acknowledgements"> <div class="c-article-section" id="Ack1-section"> <h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="Ack1">Acknowledgements</h2> <div class="c-article-section__content" id="Ack1-content"> <p>This research at ORNL’s High Flux Isotope Reactor (IMAGINE beamline) and at ORNL’s Spallation Neutron Source (MaNDi beamline) was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. The Office of Biological and Environmental Research supported research at ORNL’s Center for Structural Molecular Biology (CSMB), a DOE Office of Science User Facility. ORNL is managed by UT-Battelle LLC for DOE’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. X-ray crystallographic data were in part collected at Argonne National Laboratory using Structural Biology Center (SBC) beamline ID19 at the Advanced Photon Source. Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357. The authors thank the Institut Laue Langevin (beamline LADI-DALI) for awarded additional neutron beamtime. This research was supported by a grant from NIH-GMS (R01GM137008) to R.S.P. and A.K.</p> </div> </div> </section> <section aria-labelledby="author-information" data-title="Author information"> <div class="c-article-section" id="author-information-section"> <h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="author-information">Author information</h2> <div class="c-article-section__content" id="author-information-content"> <h3 class="c-article__sub-heading" id="affiliations">Authors and Affiliations</h3> <ol class="c-article-author-affiliation__list"> <li id="Aff1"><p class="c-article-author-affiliation__address">Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA</p><p class="c-article-author-affiliation__authors-list">Victoria N. Drago, Kevin L. Weiss & Andrey Kovalevsky</p></li> <li id="Aff2"><p class="c-article-author-affiliation__address">Department of Natural Sciences, Tennessee Wesleyan University, Athens, TN, 37303, USA</p><p class="c-article-author-affiliation__authors-list">Claudia Campos, Mattea Hooper, Aliyah Collins & Oksana Gerlits</p></li> <li id="Aff3"><p class="c-article-author-affiliation__address">Large Scale Structures Group, Institut Laue–Langevin, 71 Avenue des Martyrs, 38000, Grenoble, France</p><p class="c-article-author-affiliation__authors-list">Matthew P. Blakeley</p></li> <li id="Aff4"><p class="c-article-author-affiliation__address">Department of Chemistry, University of Georgia, Athens, GA, 30602, USA</p><p class="c-article-author-affiliation__authors-list">Robert S. 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V.N.D., C.C., M.H., A.C., O.G., K.L.W. and R.S.P. expressed and purified the proteins. V.N.D., C.C., O.G., and R.S.P. crystallized the proteins. V.N.D., M.H. and A.K. collected X-ray diffraction data. V.N.D. and A.K. reduced X-ray data and refined the structures. V.N.D., M.P.B., and A.K. collected and reduced neutron diffraction data. V.N.D. and A.K. refined joint XN structures. V.N.D. carried out quantum chemical calculations. V.N.D., R.S.P., and A.K. wrote the paper with help from all co-authors.</p> <h3 class="c-article__sub-heading" id="corresponding-author">Corresponding author</h3> <p id="corresponding-author-list">Correspondence to <a id="corresp-c1" href="mailto:kovalevskyay@ornl.gov?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=auto">Andrey Kovalevsky</a>.</p> </div> </div> </section> <section data-title="Ethics declarations"> <div class="c-article-section" id="ethics-section"> <h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="ethics">Ethics declarations</h2> <div class="c-article-section__content" id="ethics-content"> <h3 class="c-article__sub-heading" id="FPar2">Competing interests</h3> <p>The authors declare no competing interests.</p> </div> </div> </section> <section data-title="Peer review"> <div class="c-article-section" id="peer-review-section"> <h2 class="c-article-section__title js-section-title js-c-reading-companion-sections-item" id="peer-review">Peer review</h2> <div class="c-article-section__content" id="peer-review-content"> <h3 class="c-article__sub-heading" id="FPar1">Peer review information</h3> <p><i>Communications Chemistry</i> thanks Derek T. 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id="citeas">Cite this article</h3> <p class="c-bibliographic-information__citation">Drago, V.N., Campos, C., Hooper, M. <i>et al.</i> Revealing protonation states and tracking substrate in serine hydroxymethyltransferase with room-temperature X-ray and neutron crystallography. <i>Commun Chem</i> <b>6</b>, 162 (2023). https://doi.org/10.1038/s42004-023-00964-9</p> <p class="c-bibliographic-information__download-citation u-hide-print"><a data-test="citation-link" data-track="click" data-track-action="download article citation" data-track-label="link" data-track-external="" rel="nofollow" href="https://translate.google.com/website?sl=auto&tl=en&hl=auto&u=https://citation-needed.springer.com/v2/references/10.1038/s42004-023-00964-9?format%3Drefman%26flavour%3Dcitation">Download citation <svg width="16" height="16" focusable="false" role="img" aria-hidden="true" class="u-icon"> <use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="#icon-eds-i-download-medium" /> </svg></a></p> <ul 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