2dpg
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COMPLEX OF INACTIVE MUTANT (H240->N) OF GLUCOSE 6-PHOSPHATE DEHYDROGENASE FROM LEUCONOSTOC MESENTEROIDES WITH NADP+
OverviewOverview
The catalytic mechanism of glucose 6-phosphate dehydrogenase from, Leuconostoc mesenteroides was investigated by replacing three amino acids, His-240, Asp-177, and His 178, with asparagine, using site-directed, mutagenesis. Each of the mutant enzymes was purified to homogeneity and, characterized by substrate binding studies and steady-state kinetic, analyses. The three-dimensional structure of the H240N glucose 6-phosphate, dehydrogenase was determined at 2.5 A resolution. The results support a, mechanism in which His-240 acts as the general base that abstracts the, proton from the C1-hydroxyl group of glucose 6-phosphate, and the, carboxylate group of Asp-177 stabilizes the positive charge that forms on, His-240 in the transition state. The results also confirm the postulated, role of His-178 in binding the phosphate moiety of glucose 6-phosphate.
About this StructureAbout this Structure
2DPG is a Single protein structure of sequence from Leuconostoc mesenteroides with as ligand. Active as Glucose-6-phosphate 1-dehydrogenase, with EC number 1.1.1.49 Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
On the mechanism of the reaction catalyzed by glucose 6-phosphate dehydrogenase., Cosgrove MS, Naylor C, Paludan S, Adams MJ, Levy HR, Biochemistry. 1998 Mar 3;37(9):2759-67. PMID:9485426
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