FIG. 8.
A functional TOM complex is not required for capsid to block mitochondrial import. (A) Mitochondria isolated from wild-type yeast were incubated with 35S-lableled Su9-DHFR in the presence or absence of capsid for 20 min at 16°C. Where indicated, mitochondria were pretreated with trypsin to remove components of the TOM complex. Prior to SDS-PAGE and autoradiography, samples were treated with proteinase K for 30 min at 0°C to remove nonimported precursor. The mature (m) imported form of Su9-DHFR is indicated. (B) Western blot against TOM receptor Tom22 with untreated and pretrypsinized mitochondria. Mitochondrial ribosomal protein Mrpl40 served as a loading control. (C) The amounts of mature Su9-DHFR in the samples were determined and then plotted relative to the amount of protein imported into untreated mitochondria in the absence of capsid.