title: Early evolution of cytochrome bc complexes.
abstract: Primary structures, functional characteristics and phylogenetic relationships of subunits of cytochrome bc complexes from phylogenetically diverse bacterial and archaeal species were analysed. A single case of lateral gene transfer, i.e. the import of an epsilon-proteobacterial cytochrome bc(1) complex into Aquificales, was identified. For the enzyme in the remainder of the species studied, the obtained phylogenies were globally in line with small subunit rRNA trees. The distribution of a few key phylogenetic markers, such as contiguousness of cytochrome b, nature of the c-type subunit or spacing between b-heme ligands, are discussed. A localised modification of previous tree topologies is proposed on the basis of the obtained data. The comparison of extant enzymes furthermore allowed us to define the minimal functional and evolutionary core of the enzyme. The data furthermore suggest that the ancestral enzyme was put together from subunits that previously had played a role in other electron transfer chains.
authors.affiliation: Laboratoire de Bioénergétique et Ingénierie des Protéines (UPR 9036, France.
authors.forename: M
authors.initials: M
authors.lastname: Schütz
authors.forename: M
authors.initials: M
authors.lastname: Brugna
authors.forename: E
authors.initials: E
authors.lastname: Lebrun
authors.forename: F
authors.initials: F
authors.lastname: Baymann
authors.forename: R
authors.initials: R
authors.lastname: Huber
authors.forename: K O
authors.initials: KO
authors.lastname: Stetter
authors.forename: G
authors.initials: G
authors.lastname: Hauska
authors.forename: R
authors.initials: R
authors.lastname: Toci
authors.forename: D
authors.initials: D
authors.lastname: Lemesle-Meunier
authors.forename: P
authors.initials: P
authors.lastname: Tron
authors.forename: C
authors.initials: C
authors.lastname: Schmidt
authors.forename: W
authors.initials: W
authors.lastname: Nitschke
mesh_terms: D000595:Amino Acid Sequence; D001105:Archaea / Q000201:enzymology; D019414:Chlorobi / Q000201:enzymology; D000458:Cyanobacteria / Q000201:enzymology; D014450:Electron Transport Complex III / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D006094:Gram-Positive Bacteria / Q000201:enzymology; D008969:Molecular Sequence Data; D010802:Phylogeny; D020560:Proteobacteria / Q000201:enzymology; D011995:Recombination, Genetic; D016415:Sequence Alignment
chemical_list: D014450:Electron Transport Complex III