Identification of a Native Dichelobacter Nodosus Plasmid and Implications for the Evolution of the Vap Regions

Gene. 1996 Jun 12;172(1):111-6. doi: 10.1016/0378-1119(96)00032-7.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Biological Evolution*
  • Cloning, Molecular
  • DNA Transposable Elements
  • DNA, Recombinant
  • Gram-Negative Anaerobic Bacteria / genetics*
  • Molecular Sequence Data
  • Plasmids*
  • Sequence Homology, Nucleic Acid


  • DNA Transposable Elements
  • DNA, Recombinant

Associated data

  • GENBANK/U02462
  • GENBANK/U34772