NoteHuman Tyrosine tRNA Is AIso P RNA Ribozyme in Vitro Internally JS $ A Cleavab } e by E . coli Ribonuclease

Transfer RNA is an essential molecule for biologlcal system, and each tRNA molecule commonly has a c]overleaf structure. Previously, we experimentally showed that some Drosophila tRNA (tRNAAia, tRNAHis, artd tRNAMet) molecules fit to form another, non-cloyerleaf, strllcture in which the 3'-half of the tRNA molecules forms an atternatiye hairpin, and that the tRNA molecules are internally cleayed by the catalytic RNA of bacterial ribonuclease P (RNase P). Until now, the hyperprocessing reaction of tRNA has only been reported with Drosophiin tRNAs. This time, we applied the hyperprocessing reaction to one of buman tRNAs, human tyrosine tRNA, and we showed that this tRNA was also hyperprocessed by E. coti RNase P RNA. This tRNA is the first example for hyperprocessed non-DrosQphila tRNAs. The resu]ts suggest that the hyperprocessing reaction can be a useful tool to detect destablized tRNA molecules from any specles.