Abstract: PDZ domains are abundant protein interaction modules that mediate multiple biological processes and physiological functions. They recognize canonical four to five amino acids at the C-termini of partner proteins. However, there are probably more patterns of protein interaction than we currently know. More and more studies showed that PDZ domains also have non-canonical binding specificities. Researches on the non-canonical binding specificities of PDZ domains can help to enrich the protein interaction networks and discover novel functions of proteins, and will be benefit for development of save and effective drugs for disease treatment.

Key words: PDZ domain, non-canonical binding specificity, internal sequence, clinical applications