1dpg
From Proteopedia
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GLUCOSE 6-PHOSPHATE DEHYDROGENASE FROM LEUCONOSTOC MESENTEROIDES
Overview
BACKGROUND: Glucose 6-phosphate dehydrogenase (G6PD) is the first enzyme, of the pentose phosphate pathway. Normally the pathway is synthetic and, NADP-dependent, but the Gram-positive bacterium Leuconostoc mesenteroides, which does not have a complete glycolytic pathway, also uses the oxidative, enzymes of the pentose phosphate pathway for catabolic reactions, and, selects either NAD or NADP depending on the demands for catabolic or, anabolic metabolism. RESULTS: The structure of G6PD has been determined, and refined to 2.0 A resolution. The enzyme is a dimer, each subunit, consisting of two domains. The smaller domain is a classic, dinucleotide-binding fold, while the larger one is a new beta+ alpha fold, not previously seen, with a predominantly antiparallel nine-stranded, beta-sheet. There are significant structural differences in the, coenzyme-binding domains of the two subunits, caused by Pro 149 which is, cis in one subunit and trans in the other. CONCLUSIONS: The structure has, allowed us to propose the location of the active site and the, coenzyme-binding site, and suggests the role of many of the residues, conserved between species. We propose that the conserved Arg46 would, interact with both the adenine ring and the 2'-phosphate of NADP. Gln47, which is not conserved, may contribute to the change from NADP to dual, coenzyme specificity. His178, in a nine-residue peptide conserved for all, known sequences, binds a phosphate in the active site pocket. His240 is, the most likely candidate for the base to oxidize the 1-hydroxyl group of, the glucose 6-phosphate substrate.
About this Structure
1DPG is a Single protein structure of sequence from Leuconostoc mesenteroides with PO4 as ligand. Active as Glucose-6-phosphate 1-dehydrogenase, with EC number 1.1.1.49 Full crystallographic information is available from OCA.
Reference
The three-dimensional structure of glucose 6-phosphate dehydrogenase from Leuconostoc mesenteroides refined at 2.0 A resolution., Rowland P, Basak AK, Gover S, Levy HR, Adams MJ, Structure. 1994 Nov 15;2(11):1073-87. PMID:7881907
Page seeded by OCA on Tue Nov 20 13:28:22 2007
