The cbb3 oxidases are an ancient innovation of the domain bacteria

• Published in: Molecular biology and evolution Vol. 25; no. 6; pp. 1158 - 1166
• Main Authors: Ducluzeau, Anne-Lise, Ouchane, Soufian, Nitschke, Wolfgang
• Format: Journal Article
• Language: English
• Published: United States 01.06.2008
• Subjects: Bacterial Proteins - classification; Bacterial Proteins - genetics; Catalytic Domain - genetics; Electron Transport Complex IV - classification; Electron Transport Complex IV - genetics; Evolution, Molecular; Genome, Bacterial; Hemeproteins - classification; Hemeproteins - genetics; Multigene Family; Phylogeny; Protein Subunits - classification; Protein Subunits - genetics; Sequence Analysis, DNA
• ISSN: 0737-4038; 1537-1719
• DOI: 10.1093/molbev/msn062

A survey of genomes for the presence of gene clusters related to cbb(3) oxidases detected bona fide members of the family in almost all phyla of the domain Bacteria. No archaeal representatives were found. The subunit composition was seen to vary substantially between clades observed on the phylogenetic tree of the catalytic subunit CcoN. The protein diade formed by CcoN and the monoheme cytochrome CcoO appears to constitute the functionally essential "core" of the enzyme conserved in all sampled cbb(3) gene clusters. The topology of the phylogenetic tree contradicts the scenario of a recent origin of cbb(3) oxidases and substantiates the status of this family as a phylogenetic entity on the same level as the other subgroups of the heme-copper superfamily (including nitric oxide reductase). This finding resuscitates and exacerbates the conundrum of the evolutionary origin of heme-copper oxidases.