RNAase P is dependent on RNAase E action in processing monomeric RNA precursors that accumulate in an RNAase E- mutant of Escherichia coli.

Abstract A mutant strain of Escherichia coli containing a thermolabile RNAase E, an RNA processing enzyme, accumulates a number of immature RNA molecules at a non-permissive temperature. Some of these molecules are derived from ribosomal RNA transcription units and contain 5 S ribosomal RNA sequences while others are nonribosomal and contain transfer RNA sequences. In order to assess whether or not RNAase E can produce processing cleavages in such precursor tRNA molecules, we isolated monomeric RNA precursors that accumulate in this mutant strain and studied their maturation in cell-free systems. Our results show that RNAase E can introduce a cleavage near the 3′ end of some precursor tRNA molecules thereby allowing RNAase P to process the precursor molecule at its 5′ end.