Semaphorin proteins mediate signal transduction by interacting with plexin receptors; they have key roles in neuronal development and many other biological processes. Here, crystal structures are presented of the semaphorin-binding regions of plexin B1 and plexin A2 with their cognate semaphorin ectodomains. On the basis of these structures, a signalling mechanism is proposed.
- Bert J. C. Janssen
- Ross A. Robinson
- E. Yvonne Jones
