Presence of F420-dependent glucose-6-phosphate dehydrogenase in Mycobacterium and Nocardia species, but absence from Streptomyces and Corynebacterium species and methanogenic Archaea.

A range of organisms known to contain F420 or to be relatives of mycobacteria were examined for F420-dependent glucose-6-phosphate dehydrogenase (FGD) and NADP-dependent glucose-6-phosphate dehydrogenase (NADP-G6PD) activities. All free-growing Mycobacterium species examined (including a virulent Mycobacterium tuberculosis strain) had FGD activities of 0.014-0.418 mumol min-1 mg protein-1, and NADP-G6PD activities of 0.013-0.636 mumol min-1 mg-1. Armadillo-grown Mycobacterium leprae had FGD activity of 0.008 mumol min-1 mg-1, but no detectable NADP-G6PD activity. Nocardia species also had FGD activity (0.088-0.154 mumol min-1 mg-1). Streptomyces and Corynebacterium species had no FGD, but had NADP-G6PD. Methanogenic Archaea had neither activity.