ID 1.3.1.65 DE 5,6-dihydroxy-3-methyl-2-oxo-1,2,5,6-tetrahydroquinoline dehydrogenase. CA 5,6-dihydroxy-3-methyl-5,6-dihydroquinolin-2(1H)-one + NAD(+) = 5,6- CA dihydroxy-3-methyl-2-oxo-1,2-dihydroquinoline + H(+) + NADH. CC -!- Acts in the reverse direction to form part of the 3-methylquinoline CC degradation pathway in bacteria. //