View source for 2w7j


==Crystal structure of Y61AbsSHMT Glycine external aldimine==
<StructureSection load='2w7j' size='340' side='right'caption='[[2w7j]], [[Resolution|resolution]] 1.68&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2w7j]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Geobacillus_stearothermophilus Geobacillus stearothermophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2W7J OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2W7J FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.68&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GLY:GLYCINE'>GLY</scene>, <scene name='pdbligand=PLP:PYRIDOXAL-5-PHOSPHATE'>PLP</scene></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=2w7j FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2w7j OCA], [https://pdbe.org/2w7j PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2w7j RCSB], [https://www.ebi.ac.uk/pdbsum/2w7j PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2w7j ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q7SIB6_GEOSE Q7SIB6_GEOSE] 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.[HAMAP-Rule:MF_00051]
== 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/w7/2w7j_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=2w7j ConSurf].
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== Publication Abstract from PubMed ==
Serine hydroxymethyltransferase (SHMT) from Bacillus stearothermophilus (bsSHMT) is a pyridoxal 5'-phosphate-dependent enzyme that catalyses the conversion of L-serine and tetrahydrofolate to glycine and 5,10-methylene tetrahydrofolate. In addition, the enzyme catalyses the tetrahydrofolate-independent cleavage of 3-hydroxy amino acids and transamination. In this article, we have examined the mechanism of the tetrahydrofolate-independent cleavage of 3-hydroxy amino acids by SHMT. The three-dimensional structure and biochemical properties of Y51F and Y61A bsSHMTs and their complexes with substrates, especially L-allo-Thr, show that the cleavage of 3-hydroxy amino acids could proceed via Calpha proton abstraction rather than hydroxyl proton removal. Both mutations result in a complete loss of tetrahydrofolate-dependent and tetrahydrofolate-independent activities. The mutation of Y51 to F strongly affects the binding of pyridoxal 5'-phosphate, possibly as a consequence of a change in the orientation of the phenyl ring in Y51F bsSHMT. The mutant enzyme could be completely reconstituted with pyridoxal 5'-phosphate. However, there was an alteration in the lambda max value of the internal aldimine (396 nm), a decrease in the rate of reduction with NaCNBH3 and a loss of the intermediate in the interaction with methoxyamine (MA). The mutation of Y61 to A results in the loss of interaction with Calpha and Cbeta of the substrates. X-Ray structure and visible CD studies show that the mutant is capable of forming an external aldimine. However, the formation of the quinonoid intermediate is hindered. It is suggested that Y61 is involved in the abstraction of the Calpha proton from 3-hydroxy amino acids. A new mechanism for the cleavage of 3-hydroxy amino acids via Calpha proton abstraction by SHMT is proposed.

Importance of tyrosine residues of Bacillus stearothermophilus serine hydroxymethyltransferase in cofactor binding and L-allo-Thr cleavage.,Bhavani BS, Rajaram V, Bisht S, Kaul P, Prakash V, Murthy MR, Appaji Rao N, Savithri HS FEBS J. 2008 Sep;275(18):4606-19. Epub 2008 Aug 11. PMID:18699779<ref>PMID:18699779</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 2w7j" style="background-color:#fffaf0;"></div>

==See Also==
*[[Serine hydroxymethyltransferase 3D structures|Serine hydroxymethyltransferase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Geobacillus stearothermophilus]]
[[Category: Large Structures]]
[[Category: Appaji Rao N]]
[[Category: Bhavani BS]]
[[Category: Bisht S]]
[[Category: Kaul P]]
[[Category: Murthy MRN]]
[[Category: Prakash V]]
[[Category: Rajaram V]]
[[Category: Savithri HS]]