Plasmid replication functions. IV. Promoters in the replication region of plasmid R6-5.

Eight RNA polymerase binding sites have been shown to map within the EcoRI fragment E-2 (replication region RepA EcoRI fragment) of plasmid R6-5 and all but one have been shown to contain active promoters of transcription. Three of the identified promoters are located within a 2.7 kb region essential for controlled, autonomous plasmid replication and may be involved in the functional expression of the three R6-5 replication determinants that have thus far been identified, namely the origin of vegetative replication, oriV, the replication control gene, cop, and the determinant of an essential, positive-acting element, designated RepA.