FIG. 5.

The association of Ssc1 constructs with Tim44 is not impaired in ssc1-2 mutant mitochondria. (A) Coprecipitation of Ssc1 constructs with anti-Tim44. The experiment was performed essentially as described in the legend to Fig. 3B with the following modifications. ssc1-2 mitochondria were used. The mutant phenotype was induced by incubation of the mitochondria for 15 min at 37°C as described in Materials and Methods. Triton X-100 or digitonin was used for lysis of the mitochondria as indicated. No difference in the association of Ssc1 constructs was observed when wild-type mitochondria were treated at 37°C or not (results not shown). (B) Control proteins are not coprecipitated with anti-Tim44 from ssc1-2 mitochondria. The experiment was performed as described in panel A except that the preproteins F₁β-bla and Su9-F₁β were included. (C) Association of Ssc1 constructs with Tim44 in wild-type and ssc1-2 mitochondria. The amounts of Ssc1 constructs coprecipitated with anti-Tim44 were determined from wild-type and ssc1-2 mitochondria, under both Triton X-100 and digitonin conditions (means of 15 independent experiments for each condition are shown, as described in the legends to Fig. 3 and 5A). Columns 1 to 3 and 5 to 7 show the ratios of coprecipitation of imported constructs between ssc1-2 and wild-type mitochondria. Columns 4 and 8 show the ratios of coprecipitation with anti-Tim44 for endogenous Ssc1-2 versus wild-type Ssc1 (determined by immunodecoration as described in Materials and Methods).