Integrase Family of Site-Specific Recombinases

Abstract

The Lambda Int (tyrosine) family of integrases recombines DNA via site-specific recombination. Within this family, a wide variety of recombination mechanisms exists mediating a diverse set of biological functions in a wide variety of organisms. The defining feature of these enzymes is the nucleophilic attack of a scissile phosphate group by a catalytic tyrosine residue to cleave the DNA and form a high-energy 3′-phosphotyrosyl covalent intermediate. This intermediate then undergoes nucleophilic attack by a 5′-hydroxyl to reseal the DNA in an isoenergetic reaction that does not require any exogenous energy source. The integrase family can be divided into several subgroups according to the number of protomers required, the requirement for accessory DNA sequences, and the involvement of accessory factors.