The Paracoccus denitrificans cytochrome aa3 has a third subunit.
The presence of a third polypeptide subunit in Paracoccus cytochrome c oxidase is demonstrated. This protein (apparent molecular mass 23 kDa) binds dicyclohexylcarbodiimide in membranes of aerobically grown bacteria and in the purified enzyme. The N-terminal amino-acid sequence of this dicyclohexylcarbodiimide-binding protein is identical to the deduced sequence of the COIII gene product [Raitio et al. (1987) EMBO J. 6, 2825-2833]. We conclude that the aa3-type oxidase in Paracoccus is composed of at least three subunits, which correspond to the three mitochondrially coded polypeptides in the eukaryotic enzyme.
Haltia
T
T
Department of Medical Chemistry, University of Helsinki.
Puustinen
A
A
Finel
M
M
D000595:Amino Acid Sequence; D001665:Binding Sites; D002852:Chromatography, Ion Exchange; D003576:Electron Transport Complex IV / Q000032:analysis*; D008928:Mitochondria / Q000032:analysis; D010084:Oxidation-Reduction; D010230:Paracoccus / Q000201:enzymology*; D010455:Peptides / Q000032:analysis
D010455:Peptides; D003576:Electron Transport Complex IV