InterPro domain: IPR006115

6-Phosphogluconate dehydrogenase ( 1.1.1.44 ) (6PGD) is an oxidative carboxylase that catalyses the decarboxylating reduction of 6-phosphogluconate into ribulose 5-phosphate in the presence of NADP. This reaction is a component of the hexose mono-phosphate shunt and pentose phosphate pathways (PPP) [ 1 , 2 ]. Prokaryotic and eukaryotic 6PGD are proteins of about 470 amino acids whose sequence are highly conserved [ 3 ]. The protein is a homodimer in which the monomers act independently [ 4 ]: each contains a large, mainly alpha-helical domain and a smaller beta-alpha-beta domain, containing a mixed parallel and anti-parallel 6-stranded beta sheet [ 4 ]. NADP is bound in a cleft in the small domain, the substrate binding in an adjacent pocket [ 4 ].

This family represents the NADP binding domain of 6-phosphogluconate dehydrogenase which adopts a Rossman fold. The C-terminal domain is described in IPR006114 .

This domain can also be found in 3-hydroxyisobutyrate dehydrogenases (HIBADH) and related proteins [ 4 ].

1. Genetic tagging, cloning, and DNA sequence of the Synechococcus sp. strain PCC 7942 gene (gnd) encoding 6-phosphogluconate dehydrogenase. J. Bacteriol. 172, 4023-31
2. The three dimensional structure of sheep liver 6-phosphogluconate dehydrogenase at 2.6 A resolution. EMBO J. 2, 1009-14
3. Analysis of the gluconate (gnt) operon of Bacillus subtilis. Mol. Microbiol. 5, 1081-9
4. Clinical, biochemical, and molecular findings in three patients with 3-hydroxyisobutyric aciduria. Mol. Genet. Metab. 87, 243-8