Chi sites, consisting of the nucleotide octamer 5′ G-C-T-G-G-T-G-G 3′, stimulate coliphage λ recombination mediated by the Escherichia coli RecBC recombination pathway. In a sensitive genetic assay using phage λ crosses, three of four Chi-like sequences tested, namely 5′ A-C-T-G-G-T-G-G 3′, 5′ G-T-T-G-G-T-G-G 3′ and 5′ G-C-T-A-G-T-G-G 3′, had about 6%, 11% and 38% of full Chi activity, respectively. We conclude that certain Chi-like sequences manifest a spectrum of recombinational hotspot activities and may account for RecBC-mediated generalized recombination of λ lacking Chi sites.
All Science Journal Classification (ASJC) codes
- Structural Biology
- Molecular Biology