Specific template requirments of RNA replicases.

Abstract

Two RNA replicases induced in the same host by unrelated RNA bacteriophages have been purified and their responses to various RNA molecules examined. Under optimal ionic condition1s both are virtually inactive with heterologous RNA, including ribosomal and sRNA of the host. Neither replicase can function with the other''s RNA. Each recognizes the RNA genome of its origin and requires it as a template for synthetic activity. This discriminating selectivity of its replicase is of obvious advantage to a virus attempting to direct its own duplication in a cellular environment replete with other RNA molecules.