Two-dimensional NMR analyses of dynamic structures of tRNA and the regulation of codon recognition by post-transcriptional modifications.

By two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy, we analyzed dynamic structures of various tRNA species from Escherichia coli and Bacillus subtilis. Proton resonances due to the anticodon of the tRNA molecules were unambiguously identified by NOESY and 2D-HOHAHA techniques. Thus, it was found that rigidity/flexibility of the two types of modified uridines in the first position of the anticodon were certainly related with the codon recognition properties of the tRNA species.