Structural highlights
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 PubMedThe structure of the isocitrate dehydrogenase (IDH) complex with bound alpha-ketoglutarate, Ca2+, and NADPH was solved at 2.7-A resolution. The alpha-ketoglutarate binds in the active site at the same position and orientation as isocitrate, with a difference between the two bound molecules of about 0.8 A. The Ca2+ metal is coordinated by alpha-ketoglutarate, three conserved aspartate residues, and a pair of water molecules. The largest motion in the active site relative to the isocitrate enzyme complex is observed for tyrosine 160, which originally forms a hydrogen bond to the labile carboxyl group of isocitrate and moves to form a new hydrogen bond to Asp 307 in the complex with alpha-ketoglutarate. This triggers a number of significant movements among several short loops and adjoining secondary structural elements in the enzyme, most of which participate in dimer stabilization and formation of the active-site cleft. These rearrangements are similar to the ligand-binding-induced movements observed in globins and insulin and serve as a model for an enzymatic mechanism which involves local shifts of secondary structural elements during turnover, rather than large-scale domain closures or loop transitions induced by substrate binding such as those observed in hexokinase or triosephosphate isomerase. Structure of isocitrate dehydrogenase with alpha-ketoglutarate at 2.7-A resolution: conformational changes induced by decarboxylation of isocitrate.,Stoddard BL, Koshland DE Jr Biochemistry. 1993 Sep 14;32(36):9317-22. PMID:8369301[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences | ||||||||||||||||||||
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