View source for 1eqb


==X-RAY CRYSTAL STRUCTURE AT 2.7 ANGSTROMS RESOLUTION OF TERNARY COMPLEX BETWEEN THE Y65F MUTANT OF E-COLI SERINE HYDROXYMETHYLTRANSFERASE, GLYCINE AND 5-FORMYL TETRAHYDROFOLATE==
<StructureSection load='1eqb' size='340' side='right'caption='[[1eqb]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1eqb]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EQB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EQB FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FFO:N-[4-({[(6S)-2-AMINO-5-FORMYL-4-OXO-3,4,5,6,7,8-HEXAHYDROPTERIDIN-6-YL]METHYL}AMINO)BENZOYL]-L-GLUTAMIC+ACID'>FFO</scene>, <scene name='pdbligand=GLY:GLYCINE'>GLY</scene>, <scene name='pdbligand=PLP:PYRIDOXAL-5-PHOSPHATE'>PLP</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1dfo|1dfo]]</div></td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Glycine_hydroxymethyltransferase Glycine hydroxymethyltransferase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.2.1 2.1.2.1] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1eqb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1eqb OCA], [https://pdbe.org/1eqb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1eqb RCSB], [https://www.ebi.ac.uk/pdbsum/1eqb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1eqb ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/GLYA_ECOLI GLYA_ECOLI]] Catalyzes the reversible interconversion of serine and glycine with tetrahydrofolate (THF) serving as the one-carbon carrier. This reaction serves as the major source of one-carbon groups required for the biosynthesis of purines, thymidylate, methionine, and other important biomolecules. Also exhibits THF-independent aldolase activity toward beta-hydroxyamino acids, producing glycine and aldehydes, via a retro-aldol mechanism. Thus, is able to catalyze the cleavage of allothreonine and 3-phenylserine. Also catalyzes the irreversible conversion of 5,10-methenyltetrahydrofolate to 5-formyltetrahydrofolate.<ref>PMID:6190704</ref>  
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/eq/1eqb_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1eqb ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
Crystal structures of human and rabbit cytosolic serine hydroxymethyltransferase have shown that Tyr65 is likely to be a key residue in the mechanism of the enzyme. In the ternary complex of Escherichia coli serine hydroxymethyltransferase with glycine and 5-formyltetrahydrofolate, the hydroxyl of Tyr65 is one of four enzyme side chains within hydrogen-bonding distance of the carboxylate group of the substrate glycine. To probe the role of Tyr65 it was changed by site-directed mutagenesis to Phe65. The three-dimensional structure of the Y65F site mutant was determined and shown to be isomorphous with the wild-type enzyme except for the missing Tyr hydroxyl group. The kinetic properties of this mutant enzyme in catalyzing reactions with serine, glycine, allothreonine, D- and L-alanine, and 5,10-methenyltetrahydrofolate substrates were determined. The properties of the enzyme with D- and L-alanine, glycine in the absence of tetrahydrofolate, and 5, 10-methenyltetrahydrofolate were not significantly changed. However, catalytic activity was greatly decreased for serine and allothreonine cleavage and for the solvent alpha-proton exchange of glycine in the presence of tetrahydrofolate. The decreased catalytic activity for these reactions could be explained by a greater than 2 orders of magnitude increase in affinity of Y65F mutant serine hydroxymethyltransferase for these amino acids bound as the external aldimine. These data are consistent with a role for the Tyr65 hydroxyl group in the conversion of a closed active site to an open structure.

Role of tyrosine 65 in the mechanism of serine hydroxymethyltransferase.,Contestabile R, Angelaccio S, Bossa F, Wright HT, Scarsdale N, Kazanina G, Schirch V Biochemistry. 2000 Jun 27;39(25):7492-500. PMID:10858298<ref>PMID:10858298</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1eqb" style="background-color:#fffaf0;"></div>

==See Also==
*[[Serine hydroxymethyltransferase|Serine hydroxymethyltransferase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacillus coli migula 1895]]
[[Category: Glycine hydroxymethyltransferase]]
[[Category: Large Structures]]
[[Category: Angelaccio, S]]
[[Category: Bossa, F]]
[[Category: Contestabile, R]]
[[Category: Kazanina, G]]
[[Category: Scarsdale, N]]
[[Category: Schirch, V]]
[[Category: Wright, H T]]
[[Category: Aat-like fold]]
[[Category: Functional mutant]]
[[Category: Hydroxymethyltransferase]]
[[Category: One carbon metabolism]]
[[Category: Transferase]]