Comparative analysis of the replicon regions of eleven ColE2-related plasmids

Identification and analysis of the region essential for autonomous replication of 15 Colicin E plasmids (ColE plasmids) that mediate Rep protein synthesis reveal that all the plasmids share a common pathway for activation and regulation of DNA replication. Four new IncB specificity types and 5 IncA specificity types are seen, with the plasmids of the four IncA specificity types containing nine-nucleotide sequences in the loop regions of stem-loop structures. Mutations of single or several nucleotides and of the C-terminal amino acid sequences of the Rep protein help determine the binding specificity of the Rep proteins.5