A mode of action of RNase CI toward the various RNAs

A mode of action of RNase CI toward the various native RNAs was examined. The mixture of tRNA from Thermus thermophilus HB8 were exhaustively cleaved by RNase CI to produce 90% of acid-soluble fraction. Among the minor nucleotides s2T were recognized by this enzyme. RNase CI generates a linear viroid molecule by introducing one single nick into viroid circular molecule. Double stranded RNA from RNA virus, such as Cytoplasmic polyhedrosis virus (CPV) from silk worm, was cleaved at some specific sites to produce more than ten of the discrete bands electrophoretically.