1dev: CRYSTAL STRUCTURE OF SMAD2 MH2 DOMAIN BOUND TO THE SMAD-BINDING DOMAIN OF SARA
1khx: Crystal structure of a phosphorylated Smad2
1mjs: MH2 domain of transcriptional factor SMAD3
1mk2: SMAD3 SBD complex
1u7f: Crystal Structure of the phosphorylated Smad3/Smad4 heterotrimeric complex
1u7v: Crystal Structure of the phosphorylated Smad2/Smad4 heterotrimeric complex