1x8s

Publication Abstract from PubMed

PDZ protein interaction domains are typically selective for C-terminal ligands, but non-C-terminal, 'internal' ligands have also been identified. The PDZ domain from the cell polarity protein Par-6 binds C-terminal ligands and an internal sequence from the protein Pals1/Stardust. The structure of the Pals1-Par-6 PDZ complex reveals that the PDZ ligand-binding site is deformed to allow for internal binding. Whereas binding of the Rho GTPase Cdc42 to a CRIB domain adjacent to the Par-6 PDZ regulates binding of C-terminal ligands, the conformational change that occurs upon binding of Pals1 renders its binding independent of Cdc42. These results suggest a mechanism by which the requirement for a C terminus can be readily bypassed by PDZ ligands and reveal a complex set of cooperative and competitive interactions in Par-6 that are likely to be important for cell polarity regulation.

Internal recognition through PDZ domain plasticity in the Par-6-Pals1 complex.,Penkert RR, DiVittorio HM, Prehoda KE Nat Struct Mol Biol. 2004 Nov;11(11):1122-7. Epub 2004 Oct 10. PMID:15475968^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.