title: Nucleotide sequence and genetic characterization of staphylococcal bacteriophage L54a int and xis genes.
abstract: The nucleotide sequence of a staphylococcal bacteriophage L54a DNA fragment containing genes involved in site-specific recombination was determined. Mutations generated by in vitro mutagenesis were used to map and characterize the int and xis genes. The site-specific recombination functions are tightly clustered within a 1.75-kilobase stretch of DNA fragment with the gene order of attP-int-xis. The int and xis genes are transcribed divergently. The Int protein deduced from the nucleotide sequence has a molecular weight of 41,000. Int is a basic protein with 354 amino acids of which 72 are basic and 38 are acidic. The Xis protein consists of only 59 amino acids with a molecular weight of 7,180. Unlike the Xis proteins of the lambdoid bacteriophages which are all basic proteins, L54a Xis is an acidic protein containing 13 acidic and 8 basic amino acids. The Int protein is required in both integrative and excisive reactions, whereas Xis is only required in excisive reaction. A well-conserved 40-residue region, including three perfectly conserved residues found in 15 site-specific recombinases of the integrase family that have been characterized, was also found in the L54a Int protein.
authors.affiliation: Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City 66103.
authors.forename: Z H
authors.initials: ZH
authors.lastname: Ye
authors.forename: C Y
authors.initials: CY
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004279:DNA, Viral / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005814:Genes, Viral; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids; D015183:Restriction Mapping; D013204:Staphylococcus Phages / Q000235:genetics*; D013211:Staphylococcus aureus / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins