title: Common evolutionary origin of mitochondrial and rickettsial respiratory chains.
abstract: Comprehensive phylogenetic analysis of the subunits of respiratory chain was carried out using a variety of mitochondrial and bacterial sequences including those from all unfinished alpha-proteobacterial genomes known to date. Maximum likelihood, neighbor-joining, and maximum parsimony consensus trees, based on four proton-translocating complexes, placed mitochondria as a sister group to the order Rickettsiales of obligate endosymbiotic bacteria to the exclusion of free-living alpha-proteobacteria. Thus, phylogenetic relationship of most eukaryotic respiratory enzymes conforms to canonical pattern of mitochondrial ancestry, prior established in analyses of ribosomal RNAs, which are encoded by residual mitochondrial genomes. These data suggest that mitochondria may have derived from a reduced intracellular bacterium and that respiration may be the only evolutionary novelty brought into eukaryotes by mitochondrial endosymbiont.
authors: Department of General Microbiology, Gamaleya Institute of Epidemiology and Microbiology, Gamaleya Street 18, Moscow 123098, Russia. vvemilio@jscc.ru
authors: Victor V
authors: VV
authors: Emelyanov
mesh_terms: D020561:Alphaproteobacteria / Q000201:enzymology / Q000235:genetics; D000595:Amino Acid Sequence; D005075:Biological Evolution; D019069:Cell Respiration / Q000235:genetics*; D044125:Coxiellaceae / Q000201:enzymology* / Q000235:genetics*; D045222:Electron Transport Chain Complex Proteins / Q000145:classification / Q000235:genetics*; D042967:Electron Transport Complex I; D042963:Electron Transport Complex II; D014450:Electron Transport Complex III; D019143:Evolution, Molecular; D020869:Gene Expression Profiling / Q000379:methods; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D045222:Electron Transport Chain Complex Proteins; C478189:respiratory complex II; D042963:Electron Transport Complex II; D042967:Electron Transport Complex I; D014450:Electron Transport Complex III