Fig. 1.

Structure of a PDZ domain (in grey) in complex with a generic C-terminus of a ligand (in orange). The ligand is embedded between the α2 and the β2 of the PDZ binding groove. PDZ Binding Motif positions are highlighted as 0, -1, -2, -3 and -4. The conventional three binding classes are shown in the table in which X corresponds to an unspecified amino acid and Φ to a hydrophobic residue