Inhibition of viral gene expression by the catalytic RNA subunit of RNase P from Escherichia coli.

The catalytic RNA subunit (M1 RNA) of RNase P from Escherichia coli has been converted to an endoribonuclease that specifically cleaves the mRNA that encodes thymidine kinase (TK) of herpes simplex virus 1 (HSV-1). Covalent attachment to the 3' end of M1 RNA of a sequence complementary to TK mRNA results in very efficient cleavage of the target RNA in vitro. This reaction can be stimulated by proteins extracted from both E. coli and HeLa cells. When mouse cells in culture that express the novel RNA construct are infected with HSV-1, the levels of both TK mRNA and protein are reduced by approximately 80% as compared with cells that either do not express the novel RNA construct or express constructs with certain deletions that are known to abolish the catalytic activity of M1 RNA.