Catalyzes the coenzyme F420-dependent oxidation of glucose 6-phosphate to 6-phosphogluconolactone (PubMed:18434308). Appears to have a role in resistance to oxidative stress, via its consumption of G6P that serves as a source of reducing power to combat oxidative stress in mycobacteria. More precisely, is likely involved in a F420-dependent anti-oxidant mechanism that protects M.tuberculosis against oxidative stress and bactericidal agents (PubMed:23240649). Is essential for the bioreductive activation of the bicyclic 4-nitroimidazole prodrug PA-824 (a nitroimidazo-oxazine) developed for anti-tuberculosis therapy against both replicating and persistent bacteria. It does not interact directly with PA-824 but, rather, provides reduced F420 to the deazaflavin-dependent nitroreductase Ddn, which in turn activates PA-824. D-glucose 6-phosphate + H(+) + oxidized coenzyme F420-(gamma-L-Glu)(n) = 6-phospho-D-glucono-1,5-lactone + reduced coenzyme F420-(gamma-L-Glu)(n) Inhibited by citrate. Optimum pH is 6.5-7. Homodimer. Cells lacking this gene display a strong resistance to PA-824 and CGI-17341 (a nitroimidazo-oxazole). Belongs to the F420-dependent glucose-6-phosphate dehydrogenase family.