The primary structure of cytochrome P460 of Nitrosomonas europaea: Presence of a c‐heme binding motif

Cytochrome P460 and hydroxyamine oxidoreductase of Nitrosomonas europaeaboth catalyze the oxidation of hydroxylamine and contain a 460 nm‐absorbing chromophore. The gene (cyp) encoding cytochrome P460 was cloned and sequenced. The predicted amino acid sequence contains a single c‐heme binding motif (CXXCH) near the carboxy‐terminus. Cytochrome P460 shows little sequence homology to other c‐cytochromes including hydroxyamine oxidoreductase. The presence of a signal peptide and a possible c‐heme binding site suggest that the cytochrome P460 of N. europaeais periplasmic.