Figure 2.

HPLC analyses of modified nucleosides in E.coli tRNA from wild-type cells and from E.coli carrying a plasmid with a human TRM1 gene. Isolated tRNA was digested with both nuclease P1 and bacterial alkaline phosphatase before HPLC chromatography of the nucleosides. (A) Escherichia coli BL21(DE3)plysS carrying the pET15b plasmid. (B) IPTG-induced E.coli BL21(DE3)plysS harboring the pET-hTRM1 plasmid. Nucleosides were identified by their UV spectra and their relative retention times (only times between 15 and 50 min are shown). The positions for m²G and m²₂G are indicated by arrows.