FIGURE 4.

Phenotypic analysis of the yjr129cΔ yeast strain. A, comparison of overall protein synthesis between WT and yjr129cΔ yeast strains. Cultures were grown to the same A₆₀₀ in SD −Met/−Cys medium; a mix of ³⁵S-labeled methionine and cysteine was added; and total protein synthesis was measured at each time point by TCA precipitation of total protein, followed by scintillation counting. Error bars, S.D. (n = 4). B, hypersensitivity of the yjr129cΔ yeast strain to sordarin on solid medium at 37 °C. Dilutions of WT yeast cells and two independently derived yjr129cΔ mutants (JEY9581 (yjr129cΔ) and JEY10800 (yjr129cΔ*)) were grown on YPD plates containing 5 μg/ml sordarin at 30 or 37 °C for 3 days. C, hypersensitivity of the yjr129cΔ yeast strain to sordarin in liquid medium. The graph shows the growth of the WT and yjr129cΔ (JEY9581) strains in liquid YPD medium containing 0 μg/ml (wt0 and Δ0), 5 μg/ml (wt5 and Δ5), or 10 μg/ml (wt10 and Δ10) sordarin over a period of 24 h at 37 °C. Error bars, range of duplicates. D, dual luciferase assays investigating the effects of YJR129C deletion on ribosomal frameshifting. YJR129C deletion significantly alters programmed ribosomal frameshifting of the HIV-1 gag-pol but not the Ty1 +1 site, relative to the luciferase activity of control sequences, which was unaffected. n = 3; mean ± S.D.; **, p < 0.01; n.s., not significant.