A novel bacteriophage defence mechanism: the anti-restriction protein

Abstract
Bacteriophage T3 and T7 protect their DNA from restriction by producing, as the earliest detectable phage functions, anti-restriction proteins. Although the 2 phage proteins differ in their chromatographic and antigenic properties, they act by the same mechanism: the anti-restriction proteins inhibit Escherichia coli K12 restriction endonuclease by direct interaction.