ID 1.14.13.31 DE 2-nitrophenol 2-monooxygenase. AN nitrophenol oxygenase. AN OnpA. CA 2-nitrophenol + 2 NADPH + O2 + 2 H(+) = catechol + nitrite + 2 NADP(+) + CA H2O. CC -!- Involved in the metabolism of nitro-aromatic compounds by bacteria. CC -!- The enzyme contains a cytochrome b5 domain that is involved in the CC reaction, and binds FAD and heme b. //