This Pfam entry consists of both TGF-beta receptor types. This is an alignment of the hydrophilic cysteine-rich ligand-binding domains, Both receptor types, (type I and II) posses a 9 amino acid cysteine box, with the the consensus CCX{4-5}CN. The type I receptors also possess 7 extracellular residues preceding the cysteine box.

1: From receptor to nucleus: the Smad pathway. Baker JC, Harland RM; Curr Opin Genet Dev 1997;7:467-473. PMID:9309176

2: The TGF-beta superfamily: new members, new receptors, and new genetic tests of function in different organisms. Kingsley DM; Genes Dev 1994;8:133-146. PMID:8299934

3: Activin receptor-like kinases: a novel subclass of cell-surface receptors with predicted serine/threonine kinase activity. ten Dijke P, Ichijo H, Franzen P, Schulz P, Saras J, Toyoshima H, Heldin CH, Miyazono K; Oncogene 1993;8:2879-2887. PMID:8397373