title: Identification of bases required for P2 integrase core binding and recombination.
abstract: Temperate coliphage P2 integrates its genome into the host chromosome upon lysogenization via a site-specific recombination event mediated by an integrase belonging to the complex family of tyrosine recombinases. The host integration site attB (BOB') is localized in the end of the cyaR gene and shares 27 nucleotides with the core of attP (COC'). In the present study we determine the minimal attB site using an in vivo recombination assay. Ten nt on the left side (B) are found to be nonessential for recombination. We show that the integrase has higher affinity for the right side (B') compared to B and that artificial B'OB' and an attP site with a matching core (C'OC') are efficient substrates for recombination in vitro. We have analyzed single nucleotides in attB and find that sequence homology within a non-centrally located quadruplet in the hypothetical overlap region is essential for efficient recombination in vivo.
authors.affiliation: Department of Genetics, Microbiology and Toxicology, Stockholm University, SE-106 91 Stockholm, Sweden.
authors.forename: Lina
authors.initials: L
authors.lastname: Sylwan
authors.forename: Clara
authors.initials: C
authors.lastname: Frumerie
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Haggård-Ljungquist
mesh_terms: D001287:Attachment Sites, Microbiological / Q000235:genetics; D017901:Bacteriophage P2 / Q000201:enzymology* / Q000235:genetics*; D001483:Base Sequence; D004926:Escherichia coli / Q000145:classification / Q000821:virology; D015971:Gene Expression Regulation, Enzymologic; D015967:Gene Expression Regulation, Viral / Q000502:physiology*; D019426:Integrases / Q000235:genetics / Q000378:metabolism*; D017354:Point Mutation; D011485:Protein Binding; D011995:Recombination, Genetic; D016415:Sequence Alignment
chemical_list: D019426:Integrases