RNA modification is a post-transcriptional process by which certain nucleotides are altered after their initial incorporation into an RNA chain. Transfer RNAs (tRNAs) is the most heavily modified class of RNA molecules. These modifications expand the chemical and functional diversity of tRNAs and enhance their structural stability. To date, more than 100 modifications have been identified, the majority of which are specific from one domain of life. However, few modifications are extensively present in the three domains of life. Among those, the m(1)A nucleotide, which consists in the methylation at position 1 of the adenine aromatic ring, is found in tRNAs and ribosomal RNAs. In tRNAs, the m(1)A modification occurs at position 9, 14, 22, 57 and 58. The enzyme TrmK catalyzes the m(1)A formation at position 22. Here we report the backbone (1)H, (15)N and (13)C chemical shift assignments of TrmK from Bacillus subtilis obtained by heteronuclear multidimensional NMR spectroscopy as well as its secondary structure in solution as predicted by TALOS+. These assignments of TrmK pave the way for interaction studies with its tRNA substrates.
Keywords: Backbone resonance assignment; Heteronuclear NMR; Methyltransferase; TrmK; Unlabeling; m1A; tRNA.