Hydroxylates tetracenomycin A2 at positions C-4, C-4A, and C12A to give tetracenomycin C (TCM C). Hydroxylates as well 9-carboxymethyl-TCM B3 to yield 8-demethyl-TMC C, a side reaction. Antibiotic biosynthesis; tetracenomycin C biosynthesis. Belongs to the PheA/TfdB FAD monooxygenase family.