Fig. 5: Yeast urm1∆ cells expressing SaciURM1 lack tRNA thiolation at wobble uridines (U34).
A LC-MS/MS-based tRNA modification analysis of U34 nucleosides (ncm5U34, mcm5U34, mcm5s2U34) from urm1∆ strains expressing ScURM1, SaciURM1 or empty vector (ev). The red arrow marks sulfur-dependent mcm5s2U34 modification. Each measured modified nucleoside signal was normalized to total uridine content. Graphs represent the mean ± SD from n = 3 biologically independent samples; individual data points displayed as dots. Statistical significance was performed between ev control and ScURM1 or SaciURM1 expressing cells with two-sided Student’s t-test. p-values < 0.005 are indicated as ** and not significant as ns. Data values are available in Supplementary Table 4 and the Supplementary Data Excel file. B Phenotypic growth tests of urm1∆ strains expressing ScURM1, SaciURM1 alone or with overexpression of tRNAGln, tRNALys, and tRNAGlu (tQKE) from multi-copy plasmids on medium with DNA damaging reagent zeocin (top panel, right) or without (control). Similarly, thermo-sensitive growth was analyzed at 30 °C and 37 °C (bottom panel) in an urm1∆ mutant that lacks tRNA pseudouridylation gene DEG1 (urm1∆deg1∆).
