PDB 1KTZ deposited: 2002-01-18 modified: 2009-02-24
Title Crystal Structure of the Human TGF-beta Type II Receptor Extracellular Domain in Complex with TGF-beta3
Authors Deep, S., Hart, P.J., Hinck, A.P., Hinck, C.S., Shu, Z., Taylor, A.B.
Structure factors resolution 2.15 rfactor 0.201 rfree 0.215
DPI 0.52 theoretical min: 0.21

Transforming growth factor-beta (TGF-beta) is the prototype of a large family of structurally related cytokines that play key roles in maintaining cellular homeostasis by signaling through two classes of functionally distinct Ser/Thr kinase receptors, designated as type I and type II. TGF-beta initiates receptor assembly by binding with high affinity to the type II receptor. Here, we present the 2.15 A crystal structure of the extracellular ligand-binding domain of the human TGF-beta type II receptor (ecTbetaR2) in complex with human TGF-beta3. ecTbetaR2 interacts with homodimeric TGF-beta3 by binding identical finger segments at opposite ends of the growth factor. Relative to the canonical 'closed' conformation previously observed in ligand structures across the superfamily, ecTbetaR2-bound TGF-beta3 shows an altered arrangement of its monomeric subunits, designated the 'open' conformation. The mode of TGF-beta3 binding shown by ecTbetaR2 is compatible with both ligand conformations. This, in addition to the predicted mode for TGF-beta binding to the type I receptor ectodomain (ecTbetaR1), suggests an assembly mechanism in which ecTbetaR1 and ecTbetaR2 bind at adjacent positions on the ligand surface and directly contact each other via protein--protein interactions.

Nat.Struct.Biol. 2002 Mar; 9(3):203-208 doi:

Cross References
Database source Identifier Description
PubMed 11850637 NSBIEW
Biomolecule Structure Assembly Serial Assembly Type Conformational State Chains Ligands Atoms
1KTZ/1 1KTZ 1 tetramer 0 4 0 3160