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 menadione to menadiol; 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. a quinol + H(+) + oxidized coenzyme F420-(gamma-L-Glu)(n) = a quinone + reduced coenzyme F420-(gamma-L-Glu)(n) kcat is 18.7 min(-1) for the reduction of menadione. Belongs to the F420H(2)-dependent quinone reductase family.