Fig. 1. Structure of E2F-family members. E2F-1–E2F-6 contain a DNA-binding domain (DBD) and a DP-dimerization domain that includes two conserved motifs: a leucine repeat sequence (LZ) and the marked box (MB). Unlike other E2Fs, E2F-7 has two distinct DBDs and does not require DP to bind to DNA (de Bruin et al., 2003; Di Stefano et al., 2003). E2F-1–E2F-5 contain a conserved C-terminal motif that mediates association with pRB-family members (RB).