The Principle of Gateway Cloning Technology

 

 

This cloning technology is based on the nature of site-specific recombination, the integrative and excisive recombination reactions between chromosomes of Bacteriophage lambda and E. coli bacterium. The integrative recombination is catalyzed by Int (integrase) and IHF (Integration Host Factor). The recombination between attB and attP sites results in attL and attR sites that flank the integrated lambda DNA.

 

Three proteins (IHF, Int and Xis) are required for the excisive recombination. The attL and attR sites located at both sides of the inserted phage genome DNA recombine site-specifically during the excision event, reforming the attP site in lambda and the attB site in the E. coli chromosome. These biochemical reaction processes, performed in vitro, are the basis of the Gateway® Cloning Technology.