Details

Autor(en) / Beteiligte

• Arnold, Isabel
• Pfeiffer, Kathy
• Neupert, Walter
• Stuart, Rosemary A.
• Schägger, Hermann

Titel

ATP Synthase of Yeast Mitochondria

Ist Teil von

• The Journal of biological chemistry, 1999-01, Vol.274 (1), p.36-40

Ort / Verlag

Elsevier Inc

Erscheinungsjahr

1999

Link zum Volltext

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• The subunit composition of the mitochondrial ATP synthase from Saccharomyces cerevisiae was analyzed using blue native gel electrophoresis and high resolution SDS-polyacrylamide gel electrophoresis. We report here the identification of a novel subunit of molecular mass of 6,687 Da, termed subunit j (Su j). An open reading frame of 127 base pairs (ATP18), which encodes for Su j, was identified on chromosome XIII. Su j does not display sequence similarity to ATP synthase subunits from other organisms. Data base searches, however, identified a potential homolog fromSchizosaccharomyces pombe with 51% identity to Su j ofS. cerevisiae. Su j, a small protein of 59 amino acid residues, has the characteristics of an integral inner membrane protein with a single transmembrane segment. Deletion of the ATP18gene encoding Su j led to a strain (Δsu j) completely deficient in oligomycin-sensitive ATPase activity and unable to grow on nonfermentable carbon sources. The presence of Su j is required for the stable expression of subunits 6 and f of the F0 membrane sector. In the absence of Su j, spontaneously arising rho−cells were observed that lacked also ubiquinol-cytochrome creductase and cytochrome c oxidase activities. We conclude that Su j is a novel and essential subunit of yeast ATP synthase.