FIG. 4.
Neither the mcm5 nor the s2 group restricts tRNAmcm5s2UUGGlnand tRNAmcm5s2UUCGluto A-ending codons. (A) The appropriate strains (W303-1B, UMY2843, UMY3165, UMY3133, UMY3134, UMY3347, UMY3348, UMY3350, and UMY3352) carrying the indicated low-copy-number URA3 plasmid were grown in liquid SC medium for 24 h. The cells were serially diluted, spotted onto SC plates and SC plates containing 5-fluoroorotic acid (5-FOA), and incubated at 30°C for 3 days. The tQ(CUG) and tE(CUC) genes code for tRNACUGGlnand tRNACUCGlu, respectively. (B) The tq(cug)Δ, te(cuc)Δ, and their elp3Δ or tuc1Δ derivatives from panel A were transformed with an empty high-copy-number (h.c.) LEU2 vector (10) or the same plasmid harboring a gene coding for the relevant U34-containing tRNA [tQ(UUG) or tE(UUC)]. The transformants were grown in SC-Leu medium for 24 h, serially diluted, spotted onto SC-Leu plates and SC-Leu plates containing 5-FOA, and incubated at 30°C for 3 days. wt, wild type.