Integron cassette insertion: a recombination process involving a folded single strand substrate.

ABSTRACT: Integrons play a major role in the dissemination of antibiotic resistance genes among Gram-negative pathogens. Integron gene cassettes form circular intermediates carrying a recombination site, attC, and insert into an integron platform at a second site, attI, in a reaction catalyzed by an integron-specific integrase IntI. The IntI1 integron integrase preferentially binds to the 'bottom strand' of single-stranded attC. We have addressed the insertion mechanism in vivo using a recombination assay exploiting plasmid conjugation to exclusively deliver either the top or bottom strand of different integrase recombination substrates. Recombination of a single-stranded attC site with an attI site was 1000-fold higher for one strand than for the other. Conversely, following conjugative transfer of

SUBMITTER: Bouvier M 

PROVIDER: S-EPMC1356339 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature