Dre Recombinase

A recombination enzyme called Cre (Cyclization Recombination Enzyme) was identified in 1981 from the P1 phage. The gene coding region is a 38 kDa polypeptide monomer protein made up of 343 amino acids, with a total length of 1029 bp. Recombination between particular locations in DNA molecules can be catalyzed by catalytically active regions found in the C-terminal domain of Cre recombinase. 

The acronym for Locus of X-overP1 is LoxP. The 34 bp sequence may be found in the P1 phage and is made up of an 8 bp intermediate spacer region and two 13 bp reverse palindrome sequences. The spacer sequence controls the orientation of the LoxP sequence, whereas the reverse palindrome sequence serves as Cre recombinase's recognition and binding area.