New archaebacterial genes coding for redox proteins: implications for the evolution of aerobic metabolism.
Archaebacterial respiratory chains are poorly understood at the molecular level. We have cloned and sequenced a cluster of five new genes from the archaebacterium Sulfolobus acidocaldarius, four of them coding for redox proteins: a Rieske iron-sulphur protein, a cytochrome b, a subunit II of cytochrome oxidase and a blue copper protein (sulfocyanin). The fifth gene codes for a hydrophobic protein with no homologue in the databases. The gene organization and biochemical data suggest that all four redox proteins probably form part of a membrane respiratory complex together with SoxM, a previously characterized catalytic subunit of cytochrome oxidase. A phylogenetic analysis of the new protein sequences gives support to the view that an elaborate aerobic respiratory chain was already present in the last common ancestor of all living organisms.
Castresana
J
J
European Molecular Biology Laboratory, Heidelberg, Germany.
Lübben
M
M
Saraste
M
M
D000332:Aerobiosis; D000595:Amino Acid Sequence; D019843:Archaeal Proteins; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D003573:Cytochrome b Group / Q000235:genetics; D004579:Electron Transport / Q000235:genetics*; D014450:Electron Transport Complex III; D003576:Electron Transport Complex IV / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics; D007506:Iron-Sulfur Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D010084:Oxidation-Reduction; D010802:Phylogeny; D015183:Restriction Mapping; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D016945:Sulfolobus acidocaldarius / Q000235:genetics* / Q000378:metabolism
D019843:Archaeal Proteins; D001426:Bacterial Proteins; D003573:Cytochrome b Group; D007506:Iron-Sulfur Proteins; C037989:Rieske iron-sulfur protein; C094530:SoxI protein, Sulfolobus acidocaldarius; C017079:mauC protein, Methylobacterium extorquens; D003576:Electron Transport Complex IV; D014450:Electron Transport Complex III