Cre Proteins and Enzymes

The Cre (cyclization recombination) enzyme, a member of a large family of recombinases, recognizes loxP which is a sequence motif of 34 bp from the PI bateriophage. If a DNA seqment is flanked by two loxP sites in the same orientation, Cre excises that seqment leaving a single loxP site in the remaining DNA molecule. The excised DNA segment is subsequently degraded. Cre and lox comprise the Cre/lox system which was first developed in the late 1980's to artificially manipulate gene expression ...