Yeast strains deleted for SOD1 or CCS1 show defects in tRNA modification. (A) Growth of wild-type (MJY1150), sod1Δ (MJY1152), elp3Δ (UMY4563), and sod1Δ elp3Δ (MJY1205) strains. The strains were grown overnight in liquid SC medium at 30°C, 10-fold serially diluted, spotted on SC plates, and incubated at 30°C or 37°C for 3 days. (B,C) HPLC analyses of nucleosides in total tRNA isolated from wild-type (MJY1150), sod1Δ (MJY1152), and ccs1Δ (MJY1163) cells. The y-axes show absorbance units (A.U.) at 254 (B) or 240 nm (C). (D,E) Effects of sod1Δ and ccs1Δ alleles on the levels of ncm5U, mcm5U, mcm5s2U, yWpA, and yW. The peak-area for the relevant nucleoside/dinucleotide (at 254 nm) was divided by the peak area for pseudouridine (Ψ), which serves as the loading control. The values represent the mean from three independent experiments. The standard deviation is indicated. Supplemental Table S1 includes values for other modified nucleosides. (*) P < 0.05, (**) P < 0.01, ns indicates not significant (P>0.05).
