title: Analysis of a region in plasmid R386 containing two functional replicons.
abstract: A miniplasmid has been obtained from R386 by ligating EcoRI fragments with a fragment carrying a kanamycin-resistance gene. It contains a 6.8-kb Eco fragment of R386 which hybridizes strongly with several IncFI plasmid DNAs but not with the primary or secondary replicons of the F plasmid. This mini-R386 is incompatible with certain IncFI plasmids, and it appears to be one example of a previously unidentified replicon widely distributed in the IncFI group. A region of R386 not closely linked to the 6.8-kb fragment is involved in copy number control of the mini-R386, and a sequence in the same region interacts with mini-F partition functions to cause incompatibility. The 6.8-kb fragment also restricts growth of T7 bacteriophage, and an adjacent fragment restricts phage T4 growth. A further R386 sequence, sharing homology with the F secondary replicon, is capable of autonomous replication. Hence R386, like F, contains at least two functional replicons.
authors.forename: P
authors.initials: P
authors.lastname: Robinson
authors.forename: P
authors.initials: P
authors.lastname: Bergquist
authors.forename: D
authors.initials: D
authors.lastname: Lane
mesh_terms: D002455:Cell Division; D004262:DNA Restriction Enzymes; D004269:DNA, Bacterial / Q000235:genetics; D015246:Deoxyribonuclease EcoRI; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology; D005144:F Factor; D009693:Nucleic Acid Hybridization; D011815:R Factors; D012093:Replicon; D013604:T-Phages / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D004262:DNA Restriction Enzymes; D015246:Deoxyribonuclease EcoRI