title: Analysis of linear plasmid dimers in Borrelia burgdorferi sensu lato isolates: implications concerning the potential mechanism of linear plasmid replication.
abstract: The Borrelia genome is composed of a linear chromosome and a number of variable circular and linear plasmids. Atypically large linear plasmids of 92 to 105 kb have been identified in several Borrelia burgdorferi sensu lato isolates and characterized. These plasmids carry the p27 and ospAB genes, which in other isolates reside on a 50-kb plasmid. Here we demonstrate that these plasmids are dimers of the 50-kb ospAB plasmid (pAB50). The 94-kb plasmid from isolate VS116, pVS94, was an exception and did not hybridize with any plasmid gene probes. When this plasmid was used as a probe, homologous sequences in other isolates were not detected, suggesting that it is unique to isolate VS116. These analyses provide insight into the mechanism of linear plasmid replication and the mechanisms by which plasmid variability can arise.
authors.affiliation: Department of Microbiology and Immunology, Medical College of Virginia, Virginia Commonwealth University, Richmond, 23298-0678, USA.
authors.forename: R T
authors.initials: RT
authors.lastname: Marconi
authors.forename: S
authors.initials: S
authors.lastname: Casjens
authors.forename: U G
authors.initials: UG
authors.lastname: Munderloh
authors.forename: D S
authors.initials: DS
authors.lastname: Samuels
mesh_terms: D001483:Base Sequence; D015748:Borrelia burgdorferi Group / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D008969:Molecular Sequence Data; D010957:Plasmids