The Interaction of cos with Chi Is Separable from DNA Packaging in recA- recBC-Mediated Recombination of Bacteriophage Lambda

AUTOR(ES)

Kobayashi, Ichizo

RESUMO

Chi (5'-GCTGGTGG) is a recombinator in RecA- RecBC-mediated recombination in Escherichia coli. In bacteriophage λ vegetative recombination, Chi is fully active only when it is correctly oriented with respect to cos, the site that defines the ends of the packaged chromosome. Here we demonstrate that packaging from cos is not necessary for this cos-Chi interaction. Our evidence suggests that correctly oriented cos is an activator of Chi. cos, as an activator, is (1) dominant over cos-, (2) active opposite an extensive heterology, (3) able to interact with Chi only when on the same (cis) chromosome, and (4) able to interact with Chi at distances as far as ≥ 20 kb. Thus, cos and Chi form a two-component recombinator system for general recombination. cos may serve as an asymmetric entry site for a recombination enzyme that recognizes Chi in an asymmetric way.

Documentos Relacionados

• Orientation of cohesive end site cos determines the active orientation of chi sequence in stimulating recA . recBC-mediated recombination in phage lambda lytic infections.
• Coupling with Packaging Explains Apparent Nonreciprocality of Chi-Stimulated Recombination of Bacteriophage Lambda by Reca and Recbc Functions
• Suppression of recA deficiency in plasmid recombination by bacteriophage lambda beta protein in RecBCD- ExoI- Escherichia coli cells.
• The RecBC enzyme loads RecA protein onto ssDNA asymmetrically and independently of χ, resulting in constitutive recombination activation
• Studies of the interaction of RecA protein with DNA.