Figure 6.

3′-processing activity of the integrases. Reactions were performed as described under Materials and Methods. The different INs (5 pmol) were incubated with the DNA substrate (1 pmol) for 1 h at 37°C. Products were separated on denaturing (A) 12% or (B) 15% polyacrylamide gel and autoradiographed. Integrases are named according to the amino acid sequence present in the V₁₅₁E₁₅₂S₁₅₃ region. The 3′-processing reaction was performed in the presence of (A) a 5′-end radiolabeled ODN 70 hybridized to ODN 72 or (B) a 3′-end GT-radiolabeled substrate. S corresponds to the substrate and P to the processed products. The arrowhead indicates the position of the GT cyclic dinucleotide.