Fig 1.

A map of plasmid pEC156 (A). The genes coding for the EcoVIII RM system, cer locus, rom gene as well as regions with oriT F-like, oriT R64-like sequences and genes that are engaged in the priming (RNA II) and controlling the initiation of plasmid DNA replication (RNA I) are indicated. Alignment of the pEC156 nucleotide sequence with oriT of F plasmid (B) and oriT of R64 plasmid (C). The minimal region that allows oriT F-dependent plasmid mobilization is in boldface. The position of nick sites (nic) are indicated. Binding sites for plasmid F TraM (sbmA, sbmB and sbmC), TraY (sbyA and sbyC) and IHF protein as well as NikA binding site on plasmid R64 are underlined. Imperfect inverted repeats are indicated by arrows. Asterisks indicate identical nucleotides. The accession numbers of nucleotide sequences of plasmids pEC156, F and R64 that have been deposited in the Genbank database are AF158026, AP001918 and AB027308, respectively.