View source for 1fcj


==CRYSTAL STRUCTURE OF OASS COMPLEXED WITH CHLORIDE AND SULFATE==
<StructureSection load='1fcj' size='340' side='right'caption='[[1fcj]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1fcj]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Salmonella_enterica_subsp._enterica_serovar_Typhimurium Salmonella enterica subsp. enterica serovar Typhimurium]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FCJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1FCJ 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]] 2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=PLP:PYRIDOXAL-5-PHOSPHATE'>PLP</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=1fcj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1fcj OCA], [https://pdbe.org/1fcj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1fcj RCSB], [https://www.ebi.ac.uk/pdbsum/1fcj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1fcj ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CYSK_SALTY CYSK_SALTY] Two cysteine synthase enzymes are found. Both catalyze the same reaction. Cysteine synthase B can also use thiosulfate in place of sulfide to give cysteine thiosulfonate as a product.
== 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/fc/1fcj_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1fcj ConSurf].
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== Publication Abstract from PubMed ==
A new crystal structure of O-acetylserine sulfhydrylase (OASS) has been solved with chloride bound at an allosteric site and sulfate bound at the active site. The bound anions result in a new "inhibited" conformation, that differs from the "open" native or "closed" external aldimine conformations. The allosteric site is located at the OASS dimer interface. The new inhibited structure involves a change in the position of the "moveable domain" (residues 87-131) to a location that differs from that in the open or closed forms. Formation of the external aldimine with substrate is stabilized by interaction of the alpha-carboxyl group of the substrate with a substrate-binding loop that is part of the moveable domain. The inhibited conformation prevents the substrate-binding loop from interacting with the alpha-carboxyl group, and hinders formation of the external Schiff base and thus subsequent chemistry. Chloride may be an analog of sulfide, the physiological inhibitor. Finally, these results suggest that OASS represents a new class of PLP-dependent enzymes that is regulated by small anions.

Identification of an allosteric anion-binding site on O-acetylserine sulfhydrylase: structure of the enzyme with chloride bound.,Burkhard P, Tai CH, Jansonius JN, Cook PF J Mol Biol. 2000 Oct 20;303(2):279-86. PMID:11023792<ref>PMID:11023792</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Salmonella enterica subsp. enterica serovar Typhimurium]]
[[Category: Burkhard P]]
[[Category: Cook PF]]
[[Category: Jansonius JN]]
[[Category: Tai C]]