Title : Crystal structure of a truncated
epidermal growth factor receptor extracellular
domain bound to
transforming growth factor alpha
Abstract :
- We report the crystal structure, at 2.5 A resolution, of a truncated human EGFR ectodomain bound to TGFalpha
- TGFalpha interacts with both L1 and L2 domains of EGFR , making many main chain contacts with L1 and interacting with L2 via key conserved residues
- The results indicate how EGFR family members can bind a family of highly variable ligands
- In the 2:2 TGFalpha:sEGFR501 complex, each ligand interacts with only one receptor molecule
- There are two types of dimers in the asymmetric unit: a head-to-head dimer involving contacts between the L1 and L2 domains and a back-to-back dimer dominated by interactions between the CR1 domains of each receptor
- Based on sequence conservation, buried surface area, and mutagenesis experiments, the back-to-back dimer is favored to be biologically relevant