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| [[Image:1wq5.gif|left|200px]]<br /><applet load="1wq5" size="350" color="white" frame="true" align="right" spinBox="true"
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| caption="1wq5, resolution 2.30Å" />
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| '''Crystal structure of tryptophan synthase alpha-subunit from Escherichia coli'''<br />
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| ==Overview== | | ==Crystal structure of tryptophan synthase alpha-subunit from Escherichia coli== |
| When the tryptophan synthase alpha- and beta(2)-subunits combine to form the alpha(2)beta(2)-complex, the enzymatic activity of each subunit is stimulated by 1-2 orders of magnitude. To elucidate the structural basis of this mutual activation, it is necessary to determine the structures of the alpha- and beta-subunits alone and together with the alpha(2)beta(2)-complex. The crystal structures of the tryptophan synthase alpha(2)beta(2)-complex from Salmonella typhimurium (Stalpha(2)beta(2)-complex) have already been reported. However, the structures of the subunit alone from mesophiles have not yet been determined. The structure of the tryptophan synthase alpha-subunit alone from Escherichia coli (Ecalpha-subunit) was determined by an X-ray crystallographic analysis at 2.3 A, which is the first report on the subunits alone from the mesophiles. The biggest difference between the structures of the Ecalpha-subunit alone and the alpha-subunit in the Stalpha(2)beta(2)-complex (Stalpha-subunit) was as follows. Helix 2' in the Stalpha-subunit, including an active site residue (Asp60), was changed to a flexible loop in the Ecalpha-subunit alone. The conversion of the helix to a loop resulted in the collapse of the correct active site conformation. This region is also an important part for the mutual activation in the Stalpha(2)beta(2)-complex and interaction with the beta-subunit. These results suggest that the formation of helix 2'that is essential for the stimulation of the enzymatic activity of the alpha-subunit is constructed by the induced-fit mode involved in conformational changes upon interaction between the alpha- and beta-subunits. This also confirms the prediction of the conformational changes based on the thermodynamic analysis for the association between the alpha- and beta-subunits.
| | <StructureSection load='1wq5' size='340' side='right'caption='[[1wq5]], [[Resolution|resolution]] 2.30Å' scene=''> |
| | == Structural highlights == |
| | <table><tr><td colspan='2'>[[1wq5]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1WQ5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1WQ5 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]] 2.3Å</td></tr> |
| | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</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=1wq5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1wq5 OCA], [https://pdbe.org/1wq5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1wq5 RCSB], [https://www.ebi.ac.uk/pdbsum/1wq5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1wq5 ProSAT], [https://www.topsan.org/Proteins/RSGI/1wq5 TOPSAN]</span></td></tr> |
| | </table> |
| | == Function == |
| | [https://www.uniprot.org/uniprot/TRPA_ECOLI TRPA_ECOLI] 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/wq/1wq5_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=1wq5 ConSurf]. |
| | <div style="clear:both"></div> |
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| ==About this Structure== | | ==See Also== |
| 1WQ5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Tryptophan_synthase Tryptophan synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.20 4.2.1.20] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1WQ5 OCA].
| | *[[Tryptophan synthase 3D structures|Tryptophan synthase 3D structures]] |
| | | __TOC__ |
| ==Reference==
| | </StructureSection> |
| Conformational changes in the alpha-subunit coupled to binding of the beta 2-subunit of tryptophan synthase from Escherichia coli: crystal structure of the tryptophan synthase alpha-subunit alone., Nishio K, Morimoto Y, Ishizuka M, Ogasahara K, Tsukihara T, Yutani K, Biochemistry. 2005 Feb 1;44(4):1184-92. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=15667212 15667212]
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| [[Category: Escherichia coli]] | | [[Category: Escherichia coli]] |
| [[Category: Single protein]] | | [[Category: Large Structures]] |
| [[Category: Tryptophan synthase]]
| | [[Category: Ishizuka M]] |
| [[Category: Ishizuka, M.]] | | [[Category: Morimoto Y]] |
| [[Category: Morimoto, Y.]] | | [[Category: Nishio K]] |
| [[Category: Nishio, K.]] | | [[Category: Ogasahara K]] |
| [[Category: Ogasahara, K.]] | | [[Category: Tsukihara T]] |
| [[Category: RSGI, RIKEN Structural Genomics/Proteomics Initiative.]]
| | [[Category: Yutani K]] |
| [[Category: Tsukihara, T.]] | |
| [[Category: Yutani, K.]] | |
| [[Category: GOL]]
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| [[Category: SO4]]
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| [[Category: riken structural genomics/proteomics initiative]]
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| [[Category: rsgi]]
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| [[Category: structural genomics]]
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| [[Category: tryptophan]]
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| [[Category: tryptophan synthase]]
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| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:47:04 2008''
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