Ribonuclease P substrate specificity: cleavage of a bacteriophage phi80-induced RNA.

Abstract

RNase P [from Escherichia coli] can cleave in vitro a bacteriophage .vphi.80-induced RNA [M3 RNA] which is 62 nucleotides long to yield 2 specific fragments 25 and 37 nucleotides long. As is the case for another substrate of RNase P, the precursor to E. coli 4.5S RNA, the cleavage site in M3 RNA is at the end of a long double-stranded region immediately adjacent to a single-stranded segment. Similar nucleotide sequences span the cleavage site in both substrates. The reaction of RNase P with M3 and 4.5S precursor RNA are different from the reaction of this enzyme with tRNA precursor molecules. A qualitative scheme is presented for understanding the differences in RNase P cleavage site specificity for these substrates.