FIG. 6.

Reduced steady-state level of eRF3 does not alter the amount of eRF1 associated with ribosomes. Western blots indicating total and ribosome-associated eRF3 levels (A) and total and ribosome-associated eRF1 levels (B) are shown. Twenty-five micrograms of total protein was loaded per lane. Reduced expression of eRF3 was driven from the CUP1 promoter (PCUP1) in a sup35Δ strain, while the control strain expressed eRF3 from its natural promoter (PSUP35) at its genomic locus. Both strains were grown in SMD medium containing 50 μM EDTA to specifically reduce eRF3 expression from the CUP1 promoter.