Effect of RAG2 on ss DNA cleavage by R1(N+CD), R1(CD), and core RAG1. (A) Cleavage of a 5′-labeled ss WT 12-RSS substrate is shown. Each lane contains the indicated proteins, with R1(CD), R1(N+CD), and core RAG1 at 15, 2, and 10 μg/ml, respectively. Lanes 2 to 4 and 7 to 9 contain increasing concentrations of core RAG2 from 1 to 10 μg/ml. The concentration of core RAG2 in lanes 5, 11, and 12 was 10 μg/ml. The cleavage products are labeled a, b, and c. (B) GST has no effect on the cleavage activity of R1(CD) on ss DNA. Increasing concentrations of GST were added to R1(CD) and ss 12-RSS. Lanes 3 to 6 contain 15 μg of R1(CD)/ml, with lanes 4 to 6 containing increasing concentrations of GST at 0.5-, 1-, and 2-fold molar ratios of GST to R1(CD), respectively. Lanes 7 to 10 contain 30 μg of R1(CD)/ml, with lanes 8 to 10 containing increasing concentrations of GST at 0.5-, 1-, and 2-fold molar ratios of GST to R1(CD), respectively. Lane 2 contains GST alone at the same concentrations as in lanes 6 and 9. M indicates the marker lane with the lengths (in bases) of each marker indicated.