title: The IncP-1 plasmid backbone adapts to different host bacterial species and evolves through homologous recombination.
abstract: Plasmids are important members of the bacterial mobile gene pool, and are among the most important contributors to horizontal gene transfer between bacteria. They typically harbour a wide spectrum of host beneficial traits, such as antibiotic resistance, inserted into their backbones. Although these inserted elements have drawn considerable interest, evolutionary information about the plasmid backbones, which encode plasmid related traits, is sparse. Here we analyse 25 complete backbone genomes from the broad-host-range IncP-1 plasmid family. Phylogenetic analysis reveals seven clades, in which two plasmids that we isolated from a marine biofilm represent a novel clade. We also found that homologous recombination is a prominent feature of the plasmid backbone evolution. Analysis of genomic signatures indicates that the plasmids have adapted to different host bacterial species. Globally circulating IncP-1 plasmids hence contain mosaic structures of segments derived from several parental plasmids that have evolved in, and adapted to, different, phylogenetically very distant host bacterial species.
authors.affiliation: Department of Cell and Molecular Biology, Microbiology, University of Gothenburg, Box 462, SE 413 46, Gothenburg, Sweden. peter.norberg@gu.se
authors.forename: Peter
authors.initials: P
authors.lastname: Norberg
authors.forename: Maria
authors.initials: M
authors.lastname: Bergström
authors.forename: Vinay
authors.initials: V
authors.lastname: Jethava
authors.forename: Devdatt
authors.initials: D
authors.lastname: Dubhashi
authors.forename: Malte
authors.initials: M
authors.lastname: Hermansson
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics*; D004251:DNA Transposable Elements; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics*; D011995:Recombination, Genetic
chemical_list: D004251:DNA Transposable Elements