Involved in the biosynthesis of kanosamine (3-amino-3-deoxy-D-glucose), which is known to have antibiotic and antifungal properties, and to be a precursor of the antibiotic neotrehalosadiamine (3,3'-diamino-3,3'-dideoxy-alpha,beta-trehalose (NTD)). Catalyzes the oxidation of glucose 6-phosphate to 3-oxo-D-glucose 6-phosphate. It can only use NAD. D-glucose 6-phosphate + NAD(+) = 3-dehydro-D-glucose 6-phosphate + H(+) + NADH Antibiotic biosynthesis; kanosamine biosynthesis. Induced by neotrehalosadiamine. The production of neotrehalosadiamine is dormant in the wild-type strain. A mutation in the beta subunit of RNA polymerase activates the production of the neotrehalosadiamine (PubMed:14612444). Belongs to the Gfo/Idh/MocA family.