ArdB Protective Activity for Unmodified λ Phage Against EcoKI Restriction Decreases in UV-Treated Escherichia coli.

Anti-restriction proteins ArdB/KlcA specifically inhibit restriction (endonuclease) activity of restriction-modification (RM) type I systems. Molecular mechanisms of ArdB/KlcA-based anti-restriction remain unknown. In this study, we quantitate effects of ArdB on protection of unmodified λ phage DNA from EcoKI restriction.