Surface properties of the EphA3 LBD.

(A) Sequence conservation of the EphA3 LBD. Residues of EphA3 forming part of the interface with ephrin-A5 are colored by sequence conservation and other residues are colored wheat. The core of the EphA3 ephrin-binding pocket is lined by conserved residues, highlighted as blue spheres. EphA3 is shown in surface representation and the ephrin-A5 GH loop in cartoon representation. (B) Surface representation of the EphA3 LBD colored by diffusion accessibility. The two regions with poor diffusion accessibility (dark blue) are the ephrin-binding pocket (top left) and a channel near the previously described tetramerization surface [30] (bottom right). While the EphA3 LBD alone is not sufficient to form a heterotetramer, the structure nevertheless reveals a framework for residues D130, H131, G132 and V133, which have been proposed to be part of the tetramerization surface [30]. This framework includes residues R83, N85, W86 and Y180 located in a channel with poor diffusion accessibility.