Mode of degradation of tRNAs with ozone

Ozone-treatment of tRNA resulted in the degradation of guanine residues located on the loop regions, such as the anticodon and D-loop region. In addition, it became evident that the guanine residues in the consecutive sequences, such as G-G-G-G and G-G-m1G in tRNAPro, were the most susceptive to the ozone-treatment. The internucleotidic linkage of the treated tRNA was not cleaved but several fragments were obtained by a gel electrophoretic separation after heating at 60% in 1M aniline-acetate buffer (pH 4.5). Major fragments derived from tRNAPro were the 3'-half and the 5'-half molecules produced by the cleavage at the anticodon region.