title: Identification of a native Dichelobacter nodosus plasmid and implications for the evolution of the vap regions.
abstract: Studies on the role of various virulence factors of the ovine pathogen, Dichelobacter nodosus, have suffered from the absence of a mechanism for the introduction of DNA into this organism. As an initial step in the development of genetic methods, we have identified and cloned a native 10-kb plasmid, pJIR896, from a clinical isolate. This plasmid was found to be a circular form of vap region 1/3 that is found in the reference strain, A198. However, pJIR896 lacked the duplicated region present in the A198 sequence and instead contained a 1.7-kb putative insertion sequence, IS1253, which shared similarity to a number of unusual IS elements. A model is proposed for the evolution of vap region 1/3 which involves the integration of a plasmid, such as pJIR896, and subsequent rearrangements resulting from the deletion or transposition of IS1253.
authors.affiliation: Department of Microbiology, Monash University, Clayton, Victoria, Australia.
authors.forename: S J
authors.initials: SJ
authors.lastname: Billington
authors.forename: M
authors.initials: M
authors.lastname: Sinistaj
authors.forename: B F
authors.initials: BF
authors.lastname: Cheetham
authors.forename: A
authors.initials: A
authors.lastname: Ayres
authors.forename: E K
authors.initials: EK
authors.lastname: Moses
authors.forename: M E
authors.initials: ME
authors.lastname: Katz
authors.forename: J I
authors.initials: JI
authors.lastname: Rood
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004274:DNA, Recombinant; D006089:Gram-Negative Anaerobic Bacteria / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids; D012689:Sequence Homology, Nucleic Acid
chemical_list: D004251:DNA Transposable Elements; D004274:DNA, Recombinant