1pb3: Difference between revisions
No edit summary |
No edit summary |
||
| Line 4: | Line 4: | ||
|PDB= 1pb3 |SIZE=350|CAPTION= <scene name='initialview01'>1pb3</scene>, resolution 1.70Å | |PDB= 1pb3 |SIZE=350|CAPTION= <scene name='initialview01'>1pb3</scene>, resolution 1.70Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand= | |LIGAND= <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> | ||
|ACTIVITY= [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] | |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> | ||
|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]) | |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]) | ||
|DOMAIN= | |||
|RELATEDENTRY=[[1p8f|1P8F]], [[1pb1|1PB1]] | |||
|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> | |||
}} | }} | ||
| Line 25: | Line 28: | ||
[[Category: Jr., D E.Koshland.]] | [[Category: Jr., D E.Koshland.]] | ||
[[Category: Mesecar, A D.]] | [[Category: Mesecar, A D.]] | ||
[[Category: entantiomer]] | [[Category: entantiomer]] | ||
[[Category: isocitrate dehydrogense,idh]] | |||
[[Category: isocitrate dehydrogense]] | |||
[[Category: stereospecificity]] | [[Category: stereospecificity]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 22:57:19 2008'' | ||
Revision as of 22:57, 30 March 2008
| |||||||
| , resolution 1.70Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Gene: | ICD OR ICDA OR ICDE OR B1136 (Escherichia coli) | ||||||
| Activity: | Isocitrate dehydrogenase (NADP(+)), with EC number 1.1.1.42 | ||||||
| Related: | 1P8F, 1PB1
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Sites of binding and orientation in a four location model for protein stereospecificity.
OverviewOverview
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.
About this StructureAbout this Structure
1PB3 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
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:10902579
Page seeded by OCA on Sun Mar 30 22:57:19 2008