Involved in a F420-dependent anti-oxidant mechanism that protects M.tuberculosis against oxidative stress and bactericidal agents. Catalyzes the F420H(2)-dependent two-electron reduction of quinones to dihydroquinones, thereby preventing the formation of cytotoxic semiquinones obtained by the one-electron reduction pathway. In vitro, catalyzes the reduction of both benzoquinone and naphthoquinone analogs; since menaquinone is the sole quinone electron carrier in the respiratory chain in M.tuberculosis, the physiological electron acceptor for Fqr-mediated F420H(2) oxidation is therefore likely to be the endogenous menaquinone found in the membrane fraction of M.tuberculosis. Is able to use F420 species with two and five glutamate residues in its polyglutamate tail. Cannot use NADH or NADPH instead of F420H(2) as the electron donor. Is involved in the bioreductive activation of bicyclic 4-nitroimidazole prodrugs such as PA-824 and delamanid developed for anti-tuberculosis therapy against both replicating and persistent bacteria. It converts PA-824 into three primary metabolites resulting from reduction of the imidazole ring at C-3; the major one is the corresponding des-nitroimidazole that generates lethal reactive nitrogen species, including nitric oxide (NO), which appears to be responsible for the anaerobic killing activity. Ddn uses the reduced F420 produced by FGD1 to activate PA-824. Delamanid (OPC-67683) is also reduced by Ddn to its des-nitro form. a quinol + H(+) + oxidized coenzyme F420-(gamma-L-Glu)(n) = a quinone + reduced coenzyme F420-(gamma-L-Glu)(n) Belongs to the F420H(2)-dependent quinone reductase family.