Members of this family of DNA binding domains adopt a beta-trefoil fold, that is, a capped beta-barrel with internal pseudo threefold symmetry. In the DNA-binding protein LAG-1, it also is the site of mutually exclusive interactions with NotchIC (and the viral protein EBNA2) and co-repressors (SMRT/N-Cor and CIR) [1].

1: Crystal structure of the nuclear effector of Notch signaling, CSL, bound to DNA. Kovall RA, Hendrickson WA; EMBO J. 2004;23:3441-3451. PMID:15297877

2: Fungal CSL transcription factors. Prevorovsky M, Puta F, Folk P; BMC Genomics. 2007;8:233. PMID:17629904