FAD-dependent urate hydroxylase activity
Catalysis of the reaction: 7,9-dihydro-1H-purine-2,6,8(3H)-trione + NADH + H+ + O2 = 5-hydroxyisouric acid + NAD + H2O.
GO:0016709
oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, NAD(P)H as one donor, and incorporation of one atom of oxygen
is_a