title: Sip, an integrase protein with excision, circularization and integration activities, defines a new family of mobile Staphylococcus aureus pathogenicity islands.
abstract: We report the complete sequence of Staphylococcal pathogenicity island bovine 2 (SaPIbov2), encoding the biofilm-associated protein Bap. SaPIbov2 contains 24 open reading frames, including sip, which encodes a functional staphylococcal integrase protein. SaPIbov2 is bordered by 18 bp direct repeats. The integration site into the chromosome lies at the 3' end of a gene encoding GMP synthase. SaPIbov2 has extensive similarity to previously described pathogenicity islands of Staphylococcus aureus. The principal difference is that toxin genes present in the other pathogenicity islands are exchanged for a transposon-like element that carries the bap gene and genes encoding an ABC transporter and a transposase. Also, SaPIbov2 can be excised to form a circular element and can integrate site-specifically and RecA-independently at a chromosomal att site in a Sip-dependent manner. This was demonstrated both in S. aureus and with plasmid substrates ectopically in Escherichia coli. Thus, SaPIbov2 encodes a functional recombinase of the integrase family that promotes element excision and insertion/integration. In addition, we demonstrated that the presence of SaPIbov2 facilitated the persistence of S. aureus in an intramammary gland infection model. Finally, different bovine isolates of S. aureus were found to carry islands related to SaPIbov2, suggesting the existence of a family of related pathogenicity islands.
authors.affiliation: Department of Chemistry, Biochemistry and Molecular Biology, Cardenal Herrera-CEU University, Edificio seminario, 46113 Moncada, Valencia, Spain.
authors.forename: Carles
authors.initials: C
authors.lastname: Ubeda
authors.forename: Ma Angeles
authors.initials: MA
authors.lastname: Tormo
authors.forename: Carme
authors.initials: C
authors.lastname: Cucarella
authors.forename: Pilar
authors.initials: P
authors.lastname: Trotonda
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Foster
authors.forename: Iñigo
authors.initials: I
authors.lastname: Lasa
authors.forename: José R
authors.initials: JR
authors.lastname: Penadés
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018441:Biofilms; D002417:Cattle; D002874:Chromosome Mapping; D004270:DNA, Circular / Q000235:genetics / Q000378:metabolism; D005260:Female; D022761:Gene Transfer, Horizontal; D044404:Genomic Islands / Q000235:genetics*; D006801:Humans; D019426:Integrases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000382:microbiology; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D016415:Sequence Alignment; D012756:Sheep; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000201:enzymology* / Q000235:genetics* / Q000472:pathogenicity
chemical_list: D004270:DNA, Circular; D019426:Integrases