Characterization of site-specific recombination by the integrase MJ1 from enterococcal bacteriophage Phi FC1

Abstract

Bacteriophage Phi FC1 integrase (MJ1) was previously shown to perform a site-specific recombination between a phage attachment site (attP) and a host attachment site (attB) In its host, Enterococcus faecalis, and also in a non-host bacterium, Escherichia coli. Here, we investigated biochemical features of MJ1 integrase. First, MJ1 integrase could perform in vitro recombination between attP and attB in the absence of additional factors. Second, MJI integrase interacted with att sites. Electrophoretic mobility shift assays and DNase I footprinting revealed that MJ1 integrase could efficiently bind to all the att sites and that MJ I integrase recognized relatively short sequences (similar to 50bp) containing an overlapping region within attB and attP. These results demonstrate that MJ1 integrase indeed catalyzes an integrative recombination between attP and attB, the mechanism of which might be simple and unidirectional, as found in serine integrases.