alpha-D-glucose 6-phosphate + NADP+ => D-glucono-1,5-lactone 6-phosphate + NADPH + H+ Cytosolic glucose-6-phosphate dehydrogenase (G6PD) catalyzes the reaction of glucose 6-phosphate and NADP+ to form D-glucono-1,5-lactone 6-phosphate and , and NADPH + H+. Biochemical studies indicate that both G6PD dimers and tetramers are catalytically active and capable or forming under physiological conditions in vivo (Au et al. 2000). Mutations that reduce the catalytic efficientcy of G6PD are remarkably common in human populations; these appear to have a protective effect against malaria (e.g., Luzzatto and Afolayan 1968). EC Number: 1.1.1.49 Pubmed10745013 Pubmed5666113 Reactome Database ID Release 4370377 Reactome, http://www.reactome.org ReactomeREACT_1868