Oxa1p, which is required for cytochrome c oxidase and ATP synthase complex formation, is embedded in the mitochondrial inner membrane.
We have previously isolated the yeast nuclear gene OXA1 and showed that Oxa1p is required for the formation of the cytochrome c oxidase and ATP synthase complexes. We have expressed Oxa1p in E. coli and shown that it is toxic and rapidly degraded. Nevertheless, a truncated protein was successfully expressed and antibodies have been raised against this truncated protein. These antibodies recognise a protein in mitochondrially enriched fractions. In vitro mitochondrial import experiments demonstrate that the import of Oxa1p is accompanied by the cleavage of a long pre-sequence. Osmotic swelling and alkaline carbonate extraction show that Oxa1p is an integral membrane protein located in the inner membrane of mitochondria. The relationships between the sub-mitochondrial location and the function of Oxa1p are discussed.
Kermorgant
M
M
Centre de Génétique Moléculaire du CNRS, Avenue de la Terrasse, F-91198 Gif sur Yvette, France.
Bonnefoy
N
N
Dujardin
G
G
D000818:Animals; D001692:Biological Transport; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000276:immunology; D008928:Mitochondria / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure*; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; C090858:OXA1 protein; D011993:Recombinant Fusion Proteins; D003576:Electron Transport Complex IV; D006180:Proton-Translocating ATPases