1q7c
From Proteopedia
The structure of betaketoacyl-[ACP] reductase Y151F mutant in complex with NADPH fragment
Structural highlights
Function[FABG_ECOLI] Catalyzes the NADPH-dependent reduction of beta-ketoacyl-ACP substrates to beta-hydroxyacyl-ACP products, the first reductive step in the elongation cycle of fatty acid biosynthesis.[1] [2] 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 PubMedbeta-Ketoacyl-acyl carrier protein reductase (FabG) is a key component in the type II fatty acid synthase system. The structures of Escherichia coli FabG and the FabG[Y151F] mutant in binary complexes with NADP(H) reveal that mechanistically important conformational changes accompany cofactor binding. The active site Ser-Tyr-Lys triad is repositioned into a catalytically competent constellation, and a hydrogen bonded network consisting of ribose hydroxyls, the Ser-Tyr-Lys triad, and four water molecules creates a proton wire to replenish the tyrosine proton donated during catalysis. Also, a disordered loop in FabG forms a substructure in the complex that shapes the entrance to the active site. A key observation is that the nicotinamide portion of the cofactor is disordered in the FabG[Y151F].NADP(H) complex, and Tyr151 appears to be necessary for high-affinity cofactor binding. Biochemical data confirm that FabG[Y151F] is defective in NADPH binding. Finally, structural changes consistent with the observed negative cooperativity of FabG are described. Cofactor-induced conformational rearrangements establish a catalytically competent active site and a proton relay conduit in FabG.,Price AC, Zhang YM, Rock CO, White SW Structure. 2004 Mar;12(3):417-28. PMID:15016358[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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