Figure 1.

TRMT2B forms methylated m⁵U425 residue of mouse mitochondrial 12S rRNA. (A) Secondary structure of mouse mitochondrial 12S rRNA [65]. Inset the closeup of the loop of the rRNA helix 24 containing the methylated residue. (B) Mass spectra of the 12S rRNA fragment with U425 nucleotide digested by RNase T1. The upper panel corresponds to wild type cells, the middle panel corresponds to Trmt2B knockout cells, while the lower panel corresponds to the complementation of Trmt2B knockout cells by a reintroduced Trmt2B gene. Mass of 1648 Da corresponds to fully methylated fragment, 1634 Da – fragment without methyl group.