Compatible bacterial plasmids are targeted to independent cellular locations in Escherichia coli

T. Q. Ho
2002 EMBO Journal  
Targeting of DNA molecules to speci®c subcellular positions is essential for ef®cient segregation, but the mechanisms underlying these processes are poorly understood. In Escherichia coli, several plasmids belonging to different incompatibility groups (F, P1 and RK2) localize preferentially near the midcell and quartercell positions. Here we compare the relative positions of these three plasmids using¯uorescence in situ hybridization. When plasmids F and P1 were localized simultaneously using
more » ... fferentially labeled probes, the majority of foci (~75%) were well separated from each other. Similar results were found when we compared the subcellular localization of F with RK2, and RK2 with P1: regardless of the number of foci per cell or growth conditions, most of the foci (70±80%) were not in close proximity to one another. We also localized RK2 in Pseudomonas aeruginosa and Vibrio cholerae, and found that plasmid RK2 localization is conserved across bacterial species. Our results suggest that each plasmid has its own unique subcellular address, implying a mechanism for the stable co-existence of plasmids in which subcelluar targeting plays a major role.
doi:10.1093/emboj/21.7.1864 pmid:11927570 pmcid:PMC125944 fatcat:ogqeqsla5nhx7owrk5wrroiu3u