Anti-Restriction Activity of ArdB Protein against EcoAI Endonuclease

Abstract

ArdB proteins are known to inhibit the activity of type I restriction–modification (RM-I) system, in particular EcoKI (family IA). The mechanism of ArdB’s activity still remains unknown; the spectrum of targets inhibited by them has been poorly studied. In this work, it was shown that the presence of the ardB gene from R64 plasmid could suppress the activity of EcoAI endonuclease (IB family) in Escherichia coli TG1 cells. The absence of specificity of ArdB to a certain RM-I system (it inhibits both the IA- and IB-family), it can be a-ssumed that the mechanism of the anti-restriction activity of this protein does not depend on both the s-equence DNA at the recognition site and the structure of the restrictase of the RM-I systems.