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| [[Image:1pb3.jpg|left|200px]]
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| {{Structure
| | ==Sites of binding and orientation in a four location model for protein stereospecificity.== |
| |PDB= 1pb3 |SIZE=350|CAPTION= <scene name='initialview01'>1pb3</scene>, resolution 1.70Å
| | <StructureSection load='1pb3' size='340' side='right'caption='[[1pb3]], [[Resolution|resolution]] 1.70Å' scene=''> |
| |SITE=
| | == Structural highlights == |
| |LIGAND= <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>
| | <table><tr><td colspan='2'>[[1pb3]] is a 1 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=1PB3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1PB3 FirstGlance]. <br> |
| |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Isocitrate_dehydrogenase_(NADP(+)) Isocitrate dehydrogenase (NADP(+))], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.42 1.1.1.42] </span>
| | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.7Å</td></tr> |
| |GENE= ICD OR ICDA OR ICDE OR B1136 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli])
| | <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> |
| |DOMAIN=
| | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1pb3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1pb3 OCA], [https://pdbe.org/1pb3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1pb3 RCSB], [https://www.ebi.ac.uk/pdbsum/1pb3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1pb3 ProSAT]</span></td></tr> |
| |RELATEDENTRY=[[1p8f|1P8F]], [[1pb1|1PB1]]
| | </table> |
| |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1pb3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1pb3 OCA], [http://www.ebi.ac.uk/pdbsum/1pb3 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1pb3 RCSB]</span> | | == Function == |
| }}
| | [https://www.uniprot.org/uniprot/IDH_ECOLI IDH_ECOLI] |
| | == 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/pb/1pb3_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=1pb3 ConSurf]. |
| | <div style="clear:both"></div> |
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| '''Sites of binding and orientation in a four location model for protein stereospecificity.'''
| | ==See Also== |
| | | *[[Isocitrate dehydrogenase 3D structures|Isocitrate dehydrogenase 3D structures]] |
| | | __TOC__ |
| ==Overview==
| | </StructureSection> |
| The stereospecificity of the enzyme isocitrate dehydrogenase was examined by steady-state kinetics and x-ray crystallography. The enzyme has the intriguing property that the apoenzyme in the absence of divalent metal showed a selectivity for the inactive l-enantiomer of the substrate isocitrate, whereas the enzyme containing magnesium showed selectivity for the physiologically active d-enantiomer. The hydrogen atom on the C2 carbon that is transferred during the reaction was, in both the d- and l-isocitrate complexes, in an orientation very close to that expected for delivery of a hydride ion to the cosubstrate NADP+. The beta-carboxylate that is eliminated as a CO2 molecule during the reaction occupied the same site on the protein in both the d- and l-isocitrate complexes. In addition, the C3 carbon was in the same protein site in both the d- and l-enantiomers. Only the fourth group, the OH atom, was in a very different position in the apo enzyme and in the metal-containing complexes. A four-location model is necessary to explain the enantiomeric specificity of IDH in contrast to the conventional three-point attachment model. The thermodynamic and kinetic ramifications of this model are explored.
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| ==About this Structure== | |
| 1PB3 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PB3 OCA].
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| ==Reference==
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| Sites of binding and orientation in a four-location model for protein stereospecificity., Mesecar AD, Koshland DE Jr, IUBMB Life. 2000 May;49(5):457-66. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10902579 10902579]
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| [[Category: Escherichia coli]] | | [[Category: Escherichia coli]] |
| [[Category: Isocitrate dehydrogenase (NADP(+))]] | | [[Category: Large Structures]] |
| [[Category: Single protein]]
| | [[Category: Koshland Jr DE]] |
| [[Category: Jr., D E.Koshland.]] | | [[Category: Mesecar AD]] |
| [[Category: Mesecar, A D.]] | |
| [[Category: entantiomer]]
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| [[Category: isocitrate dehydrogense,idh]]
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| [[Category: stereospecificity]]
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| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 22:57:19 2008''
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