The repABC plasmid family

Plasmid. 2008 Jul;60(1):19-37. doi: 10.1016/j.plasmid.2008.03.001. Epub 2008 Apr 22.


repABC plasmids are widely distributed among alpha-proteobacteria. They are especially common in Rhizobiales. Some strains of this bacterial order can contain multiple repABC replicons indicating that this plasmid family includes several incompatibility groups. The replication and stable maintenance of these replicons depend on the presence of a repABC operon. The repABC operons sequenced to date share some general characteristics. All of them contain at least three protein-encoding genes: repA, repB and repC. The first two genes encode proteins involved in plasmid segregation, whereas repC encodes a protein crucial for replication. The origin of replication maps within the repC gene. In contrast, the centromere-like sequence (parS) can be located at various positions in the operon. In this review we will summarize current knowledge about this plasmid family, with special emphasis on their structural diversity and their complex genetic regulation. Finally, we will examine some ideas about their evolutionary origin and trends.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bacterial Proteins / genetics*
  • DNA Helicases / genetics*
  • DNA Replication / genetics
  • Multigene Family*
  • Plasmids / genetics*
  • Trans-Activators / genetics*


  • Bacterial Proteins
  • RepB protein, Bacteria
  • RepC protein, Staphylococcus aureus
  • Trans-Activators
  • replication initiator protein
  • DNA Helicases