The nucleotide sequences of the replication origins of plasmids ColA and ColD

The nucleotide sequences of the replication origin regions of plasmids ColA-CA31 and ColD-CA23 were obtained. Analysis of the nucleotide sequences showed a high degree of homology of these regions with the plasmid ColE1 region responsible for its autonomous replication. In the ColA and ColD regions involved in the regulation of replication, sites have been revealed identical to those participating in the transcription initiation of the ColE1 plasmid RNA I and primer RNA. The presumed RNA polymerase binding sites and the RNA polymerase recognition sequences are identical in ColA, ColD, and ColE1 plasmids. In spite of the differences in the nucleotide sequences, RNA I and the preprimer RNA of ColA and ColD may form structures analogous to the respective structures of ColE1.