Drosophila melanogasterXPG-like endonuclease (DmGEN) is a new cate-gory of nuclease belonging to the RAD2⁄XPG family. The DmGEN pro-tein has two nuclease domains (N and I domains) similar to XPG⁄class I nucleases; however, unlike class I nucleases, in DmGEN these two nuclease domains are positioned close to each other as in FEN-1⁄class II and EXO-1⁄ class III nucleases.