Structure of the λ att Sites Generated by int-Dependent Deletions

• Published in: Proceedings of the National Academy of Sciences - PNAS 1978-11, Vol.75 (11), p.5437-5441
• Main Authors: Hoess, Ronald H., Landy, Arthur
• Format: Article
• Language: English
• Subjects: Bacteriophages; Base Sequence; Biochemistry; Chromosomes, Bacterial; Coliphages - genetics; Coliphages - metabolism; DNA; DNA Restriction Enzymes; DNA, Bacterial - metabolism; DNA, Viral - metabolism; Enzymes; Escherichia coli - genetics; Escherichia coli - metabolism; Gels; Nucleotide sequences; Oligodeoxyribonucleotides - metabolism; Open reading frames; Power of attorney; Recombination, Genetic; Sequencing
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.75.11.5437

Bacteriophage λ integrates into the chromosome of its Escherichia coli host by means of a site-specific recombination between a locus on the phage chromosome (phage att site) and a locus on the bacterial chromosome (bacterial att site). The nucleotide sequence of four λ att sites altered in site-specific recombination has been determined. The int-dependent deletions that generated these att sites have one end point within the phage att site and extend either to the left or to the right. As a result of the new internucleotide bond created by deletion formation, these phage have alterations in the 15-base-pair common core region. The new DNA sequences brought to the att sites by the deletions, designated Δ for regions to the left and Δ ′ for regions to the right, do not share any discernible homology with their analogous counterparts in the phage att site arms, P and P′, respectively, or with the bacterial att site arms, B and B′, respectively. The finding of alterations in the 15-base-pair common core region necessitates a reinterpretation of the genetic properties of these att sites in site-specific recombination. The structure of these sites in relation to their genetic properties can be viewed as being consistent with a model in which the only specificity elements in int-dependent site-specific recombination are the common core region, O, and the phage arms, P and P′.