Cytochrome c-552/4 <p>This domain contains a di-heme elbow motif. It is found among others in cytochrome c-554 and c-552. Cytochrome c554 is a tetra-heme cytochrome involved in the oxidation of NH3 by <taxon tax_id="915">Nitrosomonas europaea</taxon> [<cite idref="PUB00025023"/>].</p>