POSITION AND DIRECTION OF STRAND EXCHANGE IN BACTERIOPHAGE-HK022 INTEGRATION

The positions of the endonucleolytic cleavages promoted by the integra se protein (Int) of coliphage HK022 within its attB site were determin ed. The protein catalyses a staggered cut, which defines an overlap se quence of 7 bp within the core site. The overlap region is at the cent er of symmetry of a palindromic sequence which appears in all four put ative art core binding sites for Int. We confirm that the order of str and exchange is similar to that in phage lambda.