9icd: Difference between revisions
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|PDB= 9icd |SIZE=350|CAPTION= <scene name='initialview01'>9icd</scene>, resolution 2.5Å | |PDB= 9icd |SIZE=350|CAPTION= <scene name='initialview01'>9icd</scene>, resolution 2.5Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand=NAP:NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE'>NAP</scene> | |LIGAND= <scene name='pdbligand=NAP:NADP+NICOTINAMIDE-ADENINE-DINUCLEOTIDE+PHOSPHATE'>NAP</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= | |GENE= | ||
|DOMAIN= | |||
|RELATEDENTRY= | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=9icd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9icd OCA], [http://www.ebi.ac.uk/pdbsum/9icd PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=9icd RCSB]</span> | |||
}} | }} | ||
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[[Category: Koshlandjunior, D E.]] | [[Category: Koshlandjunior, D E.]] | ||
[[Category: Stroud, R M.]] | [[Category: Stroud, R M.]] | ||
[[Category: oxidoreductase (nad(a)-choh(d))]] | [[Category: oxidoreductase (nad(a)-choh(d))]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 05:46:08 2008'' | ||
Revision as of 05:46, 31 March 2008
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| , resolution 2.5Å | |||||||
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| Ligands: | |||||||
| Activity: | Isocitrate dehydrogenase (NADP(+)), with EC number 1.1.1.42 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CATALYTIC MECHANISM OF NADP+-DEPENDENT ISOCITRATE DEHYDROGENASE: IMPLICATIONS FROM THE STRUCTURES OF MAGNESIUM-ISOCITRATE AND NADP+ COMPLEXES
OverviewOverview
The structures of NADP+ and magnesium isocitrate bound to the NADP(+)-dependent isocitrate dehydrogenase of Escherichia coli have been determined and refined at 2.5-A resolution. NADP+ is bound by the large domain of isocitrate dehydrogenase, a structure that has little similarity to the supersecondary structure of the nucleotide-binding domain of the lactate dehydrogenase-like family of nucleotide-binding proteins. The coenzyme-binding site confirms the fundamentally different evolution of the isocitrate dehydrogenase-like and the lactate dehydrogenase-like classes of nucleotide-binding proteins. In the magnesium-isocitrate complex, magnesium is coordinated to the alpha-carboxylate and alpha-hydroxyl oxygen of isocitrate in a manner suitable for stabilization of a negative charge on the hydroxyl oxygen during both the dehydrogenation and decarboxylation steps of the conversion of isocitrate to alpha-ketoglutarate. The metal ion is also coordinated by aspartate side chains 283' (of the second subunit of the dimer) and 307 and two water molecules in a roughly octahedral arrangement. On the basis of the geometry of the active site, the base functioning in the dehydrogenation step is most likely aspartate 283'. E. coli isocitrate dehydrogenase transfers a hydride stereospecifically to the A-side of NADP+, and models for a reactive ternary complex consistent with this stereospecificity are discussed.
About this StructureAbout this Structure
9ICD is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Catalytic mechanism of NADP(+)-dependent isocitrate dehydrogenase: implications from the structures of magnesium-isocitrate and NADP+ complexes., Hurley JH, Dean AM, Koshland DE Jr, Stroud RM, Biochemistry. 1991 Sep 3;30(35):8671-8. PMID:1888729
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