Members of this family cleave DNA substrates by a series of staggered cuts, during which the protein becomes covalently linked to the DNA through a catalytic tyrosine residue at the carboxy end of the alignment. The catalytic site residues in CRE recombinase (Swiss:P06956) are Arg-173, His-289, Arg-292 and Tyr-324.

1: Flexibility in DNA recombination: structure of the lambda integrase catalytic core. Kwon HJ, Tirumalai R, Landy A, Ellenberger T; Science 1997;276:126-131. PMID:9082984

2: Structure of Cre recombinase complexed with DNA in a site-specific recombination synapse. Guo F, Gopaul DN, van Duyne GD; Nature 1997;389:40-46. PMID:9288963