9icd

CATALYTIC MECHANISM OF NADP+-DEPENDENT ISOCITRATE DEHYDROGENASE: IMPLICATIONS FROM THE STRUCTURES OF MAGNESIUM-ISOCITRATE AND NADP+ COMPLEXESCATALYTIC MECHANISM OF NADP+-DEPENDENT ISOCITRATE DEHYDROGENASE: IMPLICATIONS FROM THE STRUCTURES OF MAGNESIUM-ISOCITRATE AND NADP+ COMPLEXES

Structural highlights 9icd is a 1 chain structure with sequence from Escherichia coli. The September 2010 RCSB PDB Molecule of the Month feature on Isocitrate Dehydrogenase by David Goodsell is 10.2210/rcsb_pdb/mom_2010_9. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: Activity: Isocitrate dehydrogenase (NADP(+)), with EC number 1.1.1.42 Resources: FirstGlance, OCA, RCSB, PDBsum Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed 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. 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Isocitrate dehydrogenase

spinqualitylabelsall models 9icd, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image