1q7c
From Proteopedia
The structure of betaketoacyl-[ACP] reductase Y151F mutant in complex with NADPH fragment
Overview
beta-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.
About this Structure
1Q7C is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
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 Page seeded by OCA on Sat May 3 05:57:29 2008
