Figure 4.

Assembly of the ATP synthase complex is impaired in Δoxa1 mitochondria. Mitochondrial from wild type (A and B) and Δoxa1 (B) strains were subjected to translation and radiolabeled for 30 min at 25°C followed by a chase period in the presence of excess cold methionine, an ATP-regenerating system and in the absence or presence of oligomycin, as indicated. Mitochondria were reisolated, lysed and subjected to SDS-PAGE, Western blotting, and autoradiography. The positions of the 54-kDa SDS-resistant complex between Atp9 and Atp6, and the 48-kDa Atp9-oligomer, are indicated, by 54k and 48k, respectively. (B) The levels of both the 54-kDa (dark gray bars) and 48-kDa (light gray bars) complexes were quantified by Phosphorimaging and are each expressed as a percentage of the total, i.e., the sum of the 54- and 48-kDa signals.