1hw6
CRYSTAL STRUCTURE OF APO-2,5-DIKETO-D-GLUCONATE REDUCTASE
OverviewOverview
A 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.
About this StructureAbout this Structure
1HW6 is a Single protein structure of sequence from Corynebacterium sp.. Full crystallographic information is available from OCA.
ReferenceReference
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 Page seeded by OCA on Fri May 2 19:17:29 2008