Mechanism localisation and control of restriction cleavage of phage T4 and lambda chromosomes in vivo.

The primary action of restriction endonuclease, cleaving infecting DNA, has been demonstrated in vivo. This primary cleavage is followed rapidly by hydrolysis of the cleaved DNA at its newly exposed termini. Infecting viruses can inactivate cytoplasmic and membrane restriction endonucleases to prevent cleavage of unmodified DNA replicas.