FIG. 5.

Yme1 is required for efficient translocation of PNPase and PNPase-DHFR. (A) PNPase-DHFR was imported into WT, mas1, Δyme1, and Δimp1 Δimp2 mitochondria (mitos) as described for Fig. 2A. (B) As shown in Fig. 2D in the same set of experiments, imported PNPase-DHFR was localized to the intermembrane space after osmotic shock. (C) Time course assays were performed for the import of PNPase, PNPase-DHFR, and Su9-DHFR (control) into WT, Δyme1, and Δtim54 mitochondria at the indicated times. Nonimported precursor was removed by trypsin treatment, and equal aliquots were separated by SDS-PAGE. The percent substrate imported was quantitated from fluorographs by use of a scanning densitometer. The amount of precursor that imported into WT mitochondria at the end time point was set at 100%.