Deletion of met22 in trm10Δ strain rescues growth sensitivity to 5FU. Strains were grown overnight in SC or SD-Leu media (if containing a tRNA overexpression plasmid), serially fourfold diluted from a starting OD600 of 1, plated on plates of corresponding media with indicated concentrations of 5FU, and incubated for 4 d at 30°C. (A) Double and triple mutants with trm10Δ and other possible genes that have been implicated in 5′–3′ tRNA decay were tested for ability to revert 5FU hypersensitivity; control TRM10 strains are shown with the same mutations, as indicated. Note that the trm10Δ 5FU hypersensitive phenotype is observed with both kanR and natR gene replacements (see control strains at top of panel). (B) Double mutants of trm10Δ with genes associated with 3′–5′ tRNA decay, and control TRM10 strains with the same mutations, as indicated. (C) Overexpression of tRNATrp or tRNAHis from plasmids was performed in the indicated TRM10 or trm10Δ strain backgrounds. The results with the vector control strain in TRM10 and trm10Δ cells are shown in the top panel.
