View source for 1bks


==TRYPTOPHAN SYNTHASE (E.C.4.2.1.20) FROM SALMONELLA TYPHIMURIUM==
<StructureSection load='1bks' size='340' side='right'caption='[[1bks]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1bks]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Salmonella_enterica_subsp._enterica_serovar_Typhimurium Salmonella enterica subsp. enterica serovar Typhimurium]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1wsy 1wsy]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BKS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1BKS 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NA:SODIUM+ION'>NA</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=1bks FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1bks OCA], [https://pdbe.org/1bks PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1bks RCSB], [https://www.ebi.ac.uk/pdbsum/1bks PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1bks ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TRPA_SALTY TRPA_SALTY] The alpha subunit is responsible for the aldol cleavage of indoleglycerol phosphate to indole and glyceraldehyde 3-phosphate.
== 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/bk/1bks_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=1bks ConSurf].
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== Publication Abstract from PubMed ==
Monovalent cations activate the pyridoxal phosphate-dependent reactions of tryptophan synthase and affect intersubunit communication in the alpha2beta2 complex. We report refined crystal structures of the tryptophan synthase alpha2beta2 complex from Salmonella typhimurium in the presence of K+ at 2.0 angstrom and of Cs+ at 2.3 angstrom. Comparison of these structures with the recently refined structure in the presence of Na+ shows that each monovalent cation binds at approximately the same position about 8 angstrom from the phosphate of pyridoxal phosphate. Na+ and K+ are coordinated to the carbonyl oxygens of beta Phe-306, beta Ser-308, and beta Gly-232 and to two or one water molecule, respectively. Cs+ is coordinated to the carbonyl oxygens of beta Phe-306, beta Ser-308, beta Gly-232, beta Val-231, beta Gly-268 and beta Leu-304. A second binding site for Cs+ is located in the beta/beta interface on the 2-fold axis with four carbonyl oxygens in the coordination sphere. In addition to local changes in structure close to the cation binding site, a number of long-range changes are observed. The K+ and Cs+ structures differ from the Na+ structure with respect to the positions of beta Asp-305, beta Lys-167, and alpha Asp-56. One unexpected result of this investigation is the movement of the side chains of beta Phe-280 and beta Tyr-279 from a position partially blocking the tunnel in the Na+ structure to a position lining the surface of the tunnel in the K+ and Cs+ structures. The results provide a structural basis for understanding the effects of cations on activity and intersubunit communication.

Exchange of K+ or Cs+ for Na+ induces local and long-range changes in the three-dimensional structure of the tryptophan synthase alpha2beta2 complex.,Rhee S, Parris KD, Ahmed SA, Miles EW, Davies DR Biochemistry. 1996 Apr 2;35(13):4211-21. PMID:8672457<ref>PMID:8672457</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 1bks" style="background-color:#fffaf0;"></div>

==See Also==
*[[Aminoacyl tRNA synthetase 3D structures|Aminoacyl tRNA synthetase 3D structures]]
*[[Tryptophan synthase 3D structures|Tryptophan synthase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Salmonella enterica subsp. enterica serovar Typhimurium]]
[[Category: Hyde CC]]