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CRYSTAL STRUCTURE OF APO-2,5-DIKETO-D-GLUCONATE REDUCTASECRYSTAL STRUCTURE OF APO-2,5-DIKETO-D-GLUCONATE REDUCTASE
Structural highlights
FunctionDKGA_CORSC Catalyzes the reduction of 2,5-diketo-D-gluconic acid (25DKG) to 2-keto-L-gulonic acid (2KLG). 5-keto-D-fructose and dihydroxyacetone can also serve as substrates. 25DKGR-A exhibits a greater selectivity for the substrate and higher thermal stability than 25DKGR-B. 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 PubMedA 1.9 A resolution X-ray structure of the apo-form of Corynebacterium 2,5-diketo-d-gluconic acid reductase A (2,5-DKGR A), a member of the aldo-keto reductase superfamily, has been determined by molecular replacement using the NADPH-bound form of the same enzyme as the search model. 2,5-DKGR A catalyzes the NADPH-dependent stereo-specific reduction of 2,5-diketo-d-gluconate (2,5-DKG) to 2-keto-l-gulonate, a precursor in the industrial production of vitamin C. An atomic-resolution structure for the apo-form of the enzyme, in conjunction with our previously reported high-resolution X-ray structure for the holo-enzyme and holo/substrate model, allows a comparative analysis of structural changes that accompany cofactor binding. The results show that regions of the active site undergo coordinated conformational changes of up to 8 A. These conformational changes result in the organization and structural rearrangement of residues associated with substrate binding and catalysis. Thus, NADPH functions not only to provide a hydride ion for catalytic reduction, but is also a critical structural component for formation of a catalytically competent form of DKGR A. Structural assembly of the active site in an aldo-keto reductase by NADPH cofactor.,Sanli G, Blaber M J Mol Biol. 2001 Jun 22;309(5):1209-18. PMID:11399090[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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