The broad, long-term objective of this proposal is to define the molecular mechanism of action and regulation of the par stability determinant encoded on the Enterococcus faecalis plasmid pAD1.
Evidence indicates that par functions as a post-segregational killing system.
The larger of the 2 RNAs, RNAI, is the toxic component of the system and encodes a 33 amino acid peptide. Four specific aims will be pursued to test this hypothesis. First, detailed structural studies on both par RNAs and their interaction complex will be performed in vitro and in vivo. Second, potential autoregulatory effects on par RNA production will be examined by a variety of genetic approaches. Third, the toxin target will be determined by identifying host proteins that interact with the RNAI-encoded peptide.