Abstract 1909 Role of Arg184 in substrate binding and coenzyme coordination by 6-hydroxynicotinate 3-monooxygenase (NicC)

6-Hydroxynicotinate 3-monooxygenase (NicC) is an essential and unique enzyme involved in the aerobic bacterial degradation of nicotinic acid (NA). It catalyzes the decarboxylative hydroxylation of 6-hydroxynicotinic acid (6-HNA) to produce 2,5-dihydroxypyridine and carbon dioxide. This reaction requires the oxidation of NADH, involving the transfer of hydride to the flavin cofactor. This hydride transfer reduces the flavin, to subsequently reaction with dioxygen to form C4a-hydroperoxyflavin involved in the hydroxylation of 6-HNA.