Identification of the minimal essential region for the replication origin of miniF plasmid.

The minimal replication origin of miniF plasmid was found to lie within a region of 217 bp in length. This region contains an AT cluster and the four 19 bp direct repeats responsible for incompatibility, termed incB. Its location coincides with hat of ori2 of plasmid F, previously inferred to be the replication starting point by electron microscopic analysis (Eichenlaub et al. 1981).