FIGURE 1.

The β-subunit of Psd1 tethers the Psd1 α-subunit to the inner membrane. A, the Psd1 constructs used are shown schematically. MT, predicted mitochondrial targeting sequence; IM, putative inner membrane sorting signal. B, mitochondrial proteins from yeast strains expressing Psd1HA, Psd1S463A, or Psd1ΔIM were separated by SDS-PAGE and visualized by immunodetection with the indicated antibodies. C, intact, swollen, or lysed (with Triton X-100) mitochondria were incubated with or without proteinase K. Subsequently, samples were subjected to SDS-PAGE, and the indicated components were visualized by immunodetection with the respective antisera. D, mitochondria were subjected to carbonate extraction. Total (T), membrane-bound (P), and soluble proteins (S) were separated by SDS-PAGE, and components were visualized by immunodetection with the indicated antisera. E, Psd1HA was precipitated with an anti-HA affinity matrix. Load (5%) and eluted proteins (100%) were separated by SDS-PAGE, and proteins were visualized by immunodetection with the indicated antisera.