The first structure of SMAD4 bound to DNA was the complex with the palindromic GTCTAGAC motif. Recently, the structures of SMAD4 MH1 domain bound to several 5GC motifs have also been determined. In all complexes, the interaction with the DNA involves a conserved β-hairpin present in the MH1 domain.
The initial structure of SMAD4 binding to DNA was a complex with the palindromic GTCTAGAC motif. More recently, the structures of SMAD4's MH1 domain bound to various 5GC motifs have been determined. In all these complexes, a conserved β-hairpin within the MH1 domain is involved in interacting with the DNA.