Cytochromes P460 and c′-beta; A new family of high-spin cytochromes c

Cytochromes-P460 of Nitrosomonas europaea and Methylococcus capsulatus (Bath), and the cytochrome c′ of M. capsulatus, believed to be involved in binding or transformation of N-oxides, are shown to represent an evolutionarily related new family of monoheme, ∼17 kDa, cytochromes c found in the genomes of diverse Proteobacteria. All members of this family have a predicted secondary structure predominantly of beta-sheets in contrast to the predominantly alpha-helical cytochromes c′ found in photoheterotrophic and denitrifying Proteobacteria.