Novel incompatibility and partition loci for the REPI replication region of plasmid ColV-K30.

The minimum pColV-K30 REPI region necessary for replication was located within a ca. 1.3-kilobase DNA segment. Adjacent to the essential replication sequences, there are two DNA regions that express incompatibility with plasmids containing the F secondary replicon of the F EcoRI fragment f7. One of these regions corresponds to incE, already described in that F plasmid fragment which expresses incompatibility with f7-containing plasmids. The other is a novel sequence that we designated incF, which confers incompatibility with REPI, P307, and f7 derivatives, cis-acting pColV-K30 sequences conferring stability to REPI-containing plasmids were also identified and localized noncontiguous to REPI, ca. 20 kilobases downstream from the aerobactin iron transport genes, which were thus flanked by REPI and its partition (par) sequences.