The tRNA modification defects in sod1Δ cells are partially suppressed by increased NCS6/NCS2 or TYW1 expression. (A,B) HPLC analyses of nucleosides in total tRNAs from sod1Δ cells (MJY1152) carrying the indicated high-copy (h.c.) or low-copy (l.c.) URA3 plasmid. The absorbance units (A.U.) were measured at 254 (A) or 240 nm (B). (C,D) Effects of the SOD1, NCS6/NCS2, and TYW1 plasmids on the abundance of indicated nucleosides/dinucleotide. The relative abundance was calculated by dividing the peak area of the relevant nucleoside/dinucleotide (at 254 nm) by the peak area for pseudouridine. The values represent the mean from three independent experiments. The standard deviation is indicated. (*) P < 0.05, (**) P < 0.01.
