Figure 5

[ PIN ⁺ ] enhances [ CHI ⁺ _PM ] formation. A. NM_PM-C_SC provides translation termination function to a sup35 mutant containing the medium [PIN ⁺] variant. sup35 medium [PIN ⁺] or [pin ^-] yeast ectopically expressing NM_PM-C_SC on media containing low or no adenine without uracil (to maintain the plasmid). Cells with the medium [PIN ⁺] variant are shown here. NM_PM-C_SC is also functional in sup35 mutant yeast with the low [PIN ⁺] variant. B. NM_PM-C_SC is inactivated in sup35 mutant cells containing the medium or low [PIN ⁺] variant and not in a [pin ^-] sup35 mutant Around 10⁷ sup35 mutant cells containing either medium [PIN ⁺] or [pin ^-] expressing NM_PM-C_SC were plated onto -Ade-Ura. The frequency of Ade⁺ colonies was estimated in sup35 yeast with medium and low [PIN ⁺] variants. The Ade⁺ frequency in sup35 yeast with high and very high [PIN ⁺] variants was not determined as suppression in these strains is enhanced compared with sup35 [pin ^-] yeast.