Figure 2.

‘Turnover’ of the HsdR subunit of EcoKI during translocation and cleavage. (A) Triplex displacement by EcoKI on 5 nM one-site linear (LIN) or supercoiled (SC) DNA substrates with 5 nM MTase and varying concentrations of HsdR, as indicated. The dashed line represents where an R₂M₂S₁ complex could form on the DNA (Figure 1). (B) Cleavage activity of EcoKI on 5 nM one-site supercoiled DNA substrate with 5 nM MTase and varying concentrations of HsdR, as indicated. OC is open circle, the intermediate of DNA cleavage cut in just one strand. The dashed lines represents where an R₂M₂S₁ complex could form on the DNA. Error bars represent the standard deviations from at least two repeat experiments.