Title : Crystal structure of an ephrin
ectodomain
Abstract :
- Eph receptor tyrosine kinases and their membrane-associated ligands, the ephrins, are essential regulators of axon guidance, cell migration, segmentation, and angiogenesis
- There are two classes of vertebrate ephrin ligands which have distinct binding specificities for their cognate receptors
- Multimerization of the ligands is required for receptor activation, and ephrin ligands themselves signal intracellularly upon binding Eph receptors
- We have determined the structure of the extracellular domain of mouse ephrin-B2
- The ephrin ectodomain is an eight-stranded beta barrel with topological similarity to plant nodulins and phytocyanins
- Based on the structure, we have identified potential surface determinants of Eph /ephrin binding specificity and a ligand dimerization region
- The high sequence similarity among ephrin ectodomains indicates that all ephrins may be modeled upon the ephrin-B2 structure presented here