FIG. 3.

Single-stranded endonuclease activity of the RAG proteins is not specific for a hairpin terminus (A) and requires both RAG1 and RAG2 (B). Reactions were performed in 1 mM Mn²⁺ and analyzed as for Fig. 1A. The 58-nt fragment derived from nicking 5 nt 5′ of the hairpin tip and the corresponding fragment derived from nicking of the linear duplex DNA substrate are indicated with arrows. The 5′-end-labeled hairpin (lanes 1 to 3) and the corresponding linear duplex DNA substrates are indicated above the lanes.