Phosphogluconate dehydrogenase
6-Phosphogluconate dehydrogenase is an enzyme in the pentose phosphate pathway. It forms ribulose 5-phosphate from 6-phosphogluconate:
It 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. Prokaryotic and eukaryotic 6PGD are proteins of about 470 amino acids whose sequences are highly conserved. The protein is a homodimer in which the monomers act independently: 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. NADP is bound in a cleft in the small domain, the substrate binding in an adjacent pocket.Clinical significance
Mutations within the gene coding this enzyme result in 6-phosphogluconate dehydrogenase deficiency, an autosomal hereditary disease affecting the red blood cells.6PGD is involved in cancer cell metabolism so 6PGD inhibitors have been sought.
