Figure 5.

(a) Two next-neighbouring P-cadherin EC1-EC2 monomers. The relative orientation of the two symmetry-related molecules allows water-mediated contacts between the N-terminal portion of the adhesion arm of each molecule and the BC-loop of domain 2 in the partner molecule, an arrangement that is reminiscent of the mutual recognition process seen in strand-swap dimers, albeit at different angular orientations. (b) Detailed representation of the water-mediated interactions between main-chain atoms of the adhesion arm of the reference molecule (shown in green) and main-chain atoms of the BC-loop in the EC2 of a partner molecule (shown in purple). This feature is symmetrical in the two interacting molecules.