Isolation and characterization of bacteriophage T3 mutants sensitive to restriction by EcoRl

Bacteriophage survival: multiple mechanisms for avoiding the deoxyribonucleic acid restriction systems of their hosts.

“…The type II restriction enzymes such as EcoRV are not blocked by the ocr gene product: T3 DNA has five EcoRV sites and is restricted both in vivo and in vitro (T7 DNA has no EcoRV sites) (76). Using T3 mutants that had acquired an EcoRI site, Miyazaki et al showed that ocr is also ineffective against this type II enzyme (90).…”