Selective cleavages of tRNAPhe with secondary and tertiary structures by enediyne antitumor antibiotics Original Research Article

Some enediyne antitumor antibiotics induce site-selective cleavages for yeast tRNAPhe with three-dimensional structure. Of special interest is the fact that tRNAPhe is specifically cleaved at the anticodon arm regions by C-1027 and esperamicin Al in the presence of Mg2+ ions. Although neocarzinostatin strongly breaks tRNAPhe at 5′-GPu steps in the absence of magnesium ions, its cleavage ability is completely lost in the presence of 100 μM Mg2+ ions. Dynemicin A, which favors an intercalative binding, causes no strand scissions for the RNA with secondary and tertiary structures. This cutting of tRNAPhe may reveal that RNA as well as DNA constitutes a therapeutically relevant target for certain enediyne antitumor antibiotics.