1ges

ANATOMY OF AN ENGINEERED NAD-BINDING SITE

spinqualitylabelsall models 1ges, resolution 1.74Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1ges is a 2 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.74Å Ligands: FAD Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GSHR_ECOLI Maintains high levels of reduced glutathione in the cytosol. 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 coenzyme specificity of Escherichia coli glutathione reductase was switched from NADP to NAD by modifying the environment of the 2'-phosphate binding site through a set of point mutations: A179G, A183G, V197E, R198M, K199F, H200D, and R204P (Scrutton NS, Berry A, Perham RN, 1990, Nature 343:38-43). In order to analyze the structural changes involved, we have determined 4 high-resolution crystal structures, i.e., the structures of the wild-type enzyme (1.86 A resolution, R-factor of 16.8%), of the wild-type enzyme ligated with NADP (2.0 A, 20.8%), of the NAD-dependent mutant (1.74 A, 16.8%), and of the NAD-dependent mutant ligated with NAD (2.2 A, 16.9%). A comparison of these structures reveals subtle differences that explain details of the specificity change. In particular, a peptide rotation occurs close to the adenosine ribose, with a concomitant change of the ribose pucker. The mutations cause a contraction of the local chain fold. Furthermore, the engineered NAD-binding site assumes a less rigid structure than the NADP site of the wild-type enzyme. A superposition of the ligated structures shows a displacement of NAD versus NADP such that the electron pathway from the nicotinamide ring to FAD is elongated, which may explain the lower catalytic efficiency of the mutant. Because the nicotinamide is as much as 15 A from the sites of the mutations, this observation reminds us that mutations may have important long-range consequences that are difficult to anticipate. Anatomy of an engineered NAD-binding site.,Mittl PR, Berry A, Scrutton NS, Perham RN, Schulz GE Protein Sci. 1994 Sep;3(9):1504-14. PMID:7833810 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Glutathione Reductase

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