Abstract: The subject invention provides a unidirectional site-specific integration system for integrating a nucleic acid into the genome of a target cell. The provided system includes a site-specific integrating expression cassette (INTEC) vector, consisting of (a) a polynucleotide of interest operably linked to a promoter, (b) a single recombination site, and (c) a hybrid recombination site. In using the subject systems for site-specific integration, the INTEC vector and integrase are introduced into the target cell and the cell is maintained under conditions sufficient to provide for site-specific integration of the nucleic acid into the target cell genome via a recombination event mediated by the site-specific recombinase. Also provided are kits that include the subject systems. The subjects systems, methods and kits find use in a variety of different applications, several representative ones of which are described in detail as well.

Abstract: The present invention provides methods to site-specifically manipulate genomes by using hybrid recombinases. Hybrid recombinases comprise a modified catalytic domain from a unidirectional serine phage integrase, fused to a foreign DNA recognition domain.