The 1.1 Å Crystal Structure of Human TGF-β Type II Receptor Ligand Binding Domain

AbstractTransforming growth factor β (TGF-β) is involved in a wide range of biological functions including development, carcinogenesis, and immune regulation. Here we report the 1.1 Å resolution crystal structure of human TGF-β type II receptor ectodomain (TBRII). The overall structure of TBRII is similar to that of activin type II receptor ectodomain (ActRII) and bone morphogenic protein receptor type IA (BRIA). It displays a three-finger toxin fold with fingers formed by the β strand pairs β1-β2, β3-β4, and β5-β6. The first finger in the TBRII is significantly longer than in ActRII and BRIA and folds tightly between the second finger and the C terminus. Surface charge distributions and hydrophobic patches predict potential TBRII binding sites