In vitro analysis of the terminator T(II) of the inhibitor antisense rna II gene from plasmid pMV158.

One element involved in the copy number control of plasmid pMV158 is the antisense RNA II. We have determined the precise size of this RNA synthesized in vitro. Transcript termination occurs at two consecutive template positions within a typical rho-independent terminator, T(II). Using a series of plasmid derivatives in which the T(II) terminator has been partially or totally removed, we have analyzed the relationship between the predicted stability of the RNA hairpin encoded by T(II) and the efficiency of in vitro intrinsic termination. All the plasmids of the pMV158 family, constituted so far of 19 replicons, harbor putative antisense RNA-encoding genes which share in common the relative location with respect to the essential rep gene, the small size, and the presence of rho-independent transcription terminators. Copyright 2001 Academic Press.