Figure 7.

Non-sequence-specific endonucleolytic activity of the integrases. Supercoiled (CC) pUC19 DNA (200 ng) was incubated as described in Materials and Methods with the different INs (5 pmol) for 2 h at 37°C. The products were separated on 1% agarose gel in the presence of ethidium bromide (50 µg/ml) and visualized under UV light. CC, native closed circular form of pUC19; OC, open circular form; L, linear form. Integrases are named according to the amino acid sequence present in the V₁₅₁E₁₅₂S₁₅₃ region.