Figure 3: Substrate specificity and kinetics of plasmid cleavage by the endonuclease. (a) Plasmids DNAs including pBluescript II KS, pUC118, pET-15b, and pET-26b as indicated were incubated with the purified endonuclease in buffer R for 0 and 60 min as described in Section 2. (b) Endonuclease (12 μg) was incubated with supercoiled pBluescript (6 μg) in buffer R at 37°C (total volume 100 μL). At various time points as indicated, aliquots of reaction mixture were withdrawn and analyzed on 1% agarose gel. Supercoiled DNA (S); an open circular DNA (O); linearized DNA (L).