View source for 2clk


==Tryptophan Synthase in complex with D-glyceraldehyde 3-phosphate (G3P)==
<StructureSection load='2clk' size='340' side='right'caption='[[2clk]], [[Resolution|resolution]] 1.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2clk]] 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]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2CLK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2CLK 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]] 1.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=G3H:GLYCERALDEHYDE-3-PHOSPHATE'>G3H</scene>, <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=2clk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2clk OCA], [https://pdbe.org/2clk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2clk RCSB], [https://www.ebi.ac.uk/pdbsum/2clk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2clk 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/cl/2clk_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=2clk ConSurf].
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== Publication Abstract from PubMed ==
Allosteric interactions regulate substrate channeling in Salmonella typhimurium tryptophan synthase. The channeling of indole between the alpha- and beta-sites via the interconnecting 25 A tunnel is regulated by allosteric signaling arising from binding of ligand to the alpha-site, and covalent reaction of l-Ser at the beta-site. This signaling switches the alpha- and beta-subunits between open conformations of low activity and closed conformations of high activity. Our objective is to synthesize and characterize new classes of alpha-site ligands (ASLs) that mimic the binding of substrates, 3-indole-d-glycerol 3'-phosphate (IGP) or d-glyceraldehyde 3-phosphate (G3P), for use in the investigation of alpha-site-beta-site interactions. The new synthesized IGP analogues contain an aryl group linked to an O-phosphoethanolamine moiety through amide, sulfonamide, or thiourea groups. The G3P analogue, thiophosphoglycolohydroxamate, contains a hydroxamic acid group linked to a thiophosphate moiety. Crystal structures of the internal aldimine complexed with G3P and with three of the new ASLs are presented. These structural and solution studies of the ASL complexes with the internal aldimine form of the enzyme establish the following. (1) ASL binding occurs with high specificity and relatively high affinities at the alpha-site. (2) Binding of the new ASLs slows the entry of indole analogues into the beta-site by blocking the tunnel opening at the alpha-site. (3) ASL binding stabilizes the closed conformations of the beta-subunit for the alpha-aminoacrylate and quinonoid forms of the enzyme. (4) The new ASLs exhibit allosteric properties that parallel the behaviors of IGP and G3P.

Synthesis and characterization of allosteric probes of substrate channeling in the tryptophan synthase bienzyme complex.,Ngo H, Harris R, Kimmich N, Casino P, Niks D, Blumenstein L, Barends TR, Kulik V, Weyand M, Schlichting I, Dunn MF Biochemistry. 2007 Jul 3;46(26):7713-27. Epub 2007 Jun 9. PMID:17559195<ref>PMID:17559195</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 2clk" style="background-color:#fffaf0;"></div>

==See Also==
*[[Tryptophan synthase 3D structures|Tryptophan synthase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Salmonella enterica subsp. enterica serovar Typhimurium]]
[[Category: Barends TR]]
[[Category: Blumenstein L]]
[[Category: Casino P]]
[[Category: Dunn MF]]
[[Category: Harris R]]
[[Category: Kimmich N]]
[[Category: Kulik V]]
[[Category: Ngo H]]
[[Category: Niks D]]
[[Category: Schlichting I]]
[[Category: Weyand M]]