THE PRIMARY STRUCTURE OF CYTOCHROME P460 OF NITROSOMONAS-EUROPAEA - PRESENCE OF A C-HEME BINDING MOTIF

Cytochrome P460 and hydroxyamine oxidoreductase of Nitrosomonas europa ea both catalyze the oxidation of hydroxylamine and contain a 460 nm-a bsorbing chromophore. The gene (cyp) encoding cytochrome P460 was clon ed and sequenced. The predicted amino acid sequence contains a single c-heme binding motif (CXXCH) near the carboxy-terminus. Cytochrome P46 0 shows little sequence-homology to other c-cytochromes including hydr oxyamine oxidoreductase. The presence of a signal peptide and a possib le c-heme binding site suggest that the cytochrome P460 of N. europaea is periplasmic.