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| - | [[Image:1aj8.gif|left|200px]]<br /><applet load="1aj8" size="350" color="white" frame="true" align="right" spinBox="true" | |
| - | caption="1aj8, resolution 1.9Å" /> | |
| - | '''CITRATE SYNTHASE FROM PYROCOCCUS FURIOSUS'''<br /> | |
| | | | |
| - | ==Overview== | + | ==CITRATE SYNTHASE FROM PYROCOCCUS FURIOSUS== |
| - | The crystal structure of the closed form of citrate synthase, with citrate, and CoA bound, from the hyperthermophilic Archaeon Pyrococcus furiosus has, been determined to 1.9 A. This has allowed direct structural comparisons, between the same enzyme from organisms growing optimally at 37 degrees C, (pig), 55 degrees C (Thermoplasma acidophilum) and now 100 degrees C, (Pyrococcus furiosus). The three enzymes are homodimers and share a, similar overall fold, with the dimer interface comprising primarily an, eight alpha-helical sandwich of four antiparallel pairs of helices. The, active sites show similar modes of substrate binding; moreover, the, structural equivalence of the amino acid residues implicated in catalysis, implies that the mechanism proceeds via the same acid-base catalytic, process. Given the overall structural and mechanistic similarities, it has, been possible to make detailed structural comparisons between the three, citrate synthases, and a number of differences can be identified in, passing from the mesophilic to thermophilic to hyperthermophilic citrate, synthases. The most significant of these are an increased compactness of, the enzyme, a more intimate association of the subunits, an increase in, intersubunit ion pairs, and a reduction in thermolabile residues., Compactness is achieved by the shortening of a number of loops, an, increase in the number of atoms buried from solvent, an optimized packing, of side chains in the interior, and an absence of cavities. The intimate, subunit association in the dimeric P. furiosus enzyme is achieved by, greater complementarity of the monomers and by the C-terminal region of, each monomer folding over the surface of the other monomer, in contrast to, the pig enzyme where the C-terminus has a very different fold. The, increased number of intersubunit ion pairs is accompanied by an increase, in the number involved in networks. Interestingly, all loop regions in the, P. furiosus enzyme either are shorter or contain additional ion pairs, compared with the pig enzyme. The possible relevance of these structural, features to enzyme hyperthermostability is discussed.
| + | <StructureSection load='1aj8' size='340' side='right'caption='[[1aj8]], [[Resolution|resolution]] 1.90Å' scene=''> |
| | + | == Structural highlights == |
| | + | <table><tr><td colspan='2'>[[1aj8]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pyrococcus_furiosus Pyrococcus furiosus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AJ8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1AJ8 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]] 1.9Å</td></tr> |
| | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene>, <scene name='pdbligand=COA:COENZYME+A'>COA</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=1aj8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1aj8 OCA], [https://pdbe.org/1aj8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1aj8 RCSB], [https://www.ebi.ac.uk/pdbsum/1aj8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1aj8 ProSAT]</span></td></tr> |
| | + | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/CISY_PYRFU CISY_PYRFU] |
| | + | == 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/aj/1aj8_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=1aj8 ConSurf]. |
| | + | <div style="clear:both"></div> |
| | | | |
| - | ==About this Structure== | + | ==See Also== |
| - | 1AJ8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_furiosus Pyrococcus furiosus] with <scene name='pdbligand=COA:'>COA</scene> and <scene name='pdbligand=CIT:'>CIT</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Transferred_entry:_2.3.3.1 Transferred entry: 2.3.3.1], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.3.7 4.1.3.7] Known structural/functional Sites: <scene name='pdbsite=ACA:Catalytic+Residues'>ACA</scene> and <scene name='pdbsite=ACB:Catalytic+Residues'>ACB</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AJ8 OCA].
| + | *[[Citrate Synthase 3D structures|Citrate Synthase 3D structures]] |
| - | | + | __TOC__ |
| - | ==Reference==
| + | </StructureSection> |
| - | The crystal structure of citrate synthase from the hyperthermophilic archaeon pyrococcus furiosus at 1.9 A resolution,., Russell RJ, Ferguson JM, Hough DW, Danson MJ, Taylor GL, Biochemistry. 1997 Aug 19;36(33):9983-94. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=9254593 9254593]
| + | [[Category: Large Structures]] |
| | [[Category: Pyrococcus furiosus]] | | [[Category: Pyrococcus furiosus]] |
| - | [[Category: Single protein]]
| + | [[Category: Danson MJ]] |
| - | [[Category: Transferred entry: 2.3.3.1]]
| + | [[Category: Ferguson JMC]] |
| - | [[Category: Danson, M.J.]] | + | [[Category: Hough DW]] |
| - | [[Category: Ferguson, J.M.C.]] | + | [[Category: Russell RJM]] |
| - | [[Category: Hough, D.W.]] | + | [[Category: Taylor GL]] |
| - | [[Category: Russell, R.J.M.]] | + | |
| - | [[Category: Taylor, G.L.]] | + | |
| - | [[Category: CIT]]
| + | |
| - | [[Category: COA]]
| + | |
| - | [[Category: hyperthermostable]]
| + | |
| - | [[Category: lyase]]
| + | |
| - | | + | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 09:30:34 2008''
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