betaPIX_CC is the very C-terminal coiled-coil region of betaPIX or p21-activated kinase interacting exchange factor proteins. The coiled-coil runs from residues 589-646 in UniProtKB:G31IU6, and the PDZ-binding site is the final eight residues immediately downstream. The coiled-coil trimerises and thus exposes three potential PZD-binding surfaces, although only one of these is maximally used. One of the C-terminal ends of the coiled-coil forms an extensive beta-sheet interaction with the Shank PDZ, while the other two ends are not involved in ligand binding and form random coils. Thus the coiled-coil domain allows multimerisation of betaPIX that is vital for its physiological functions. betaPIX and the Shank/ProSAP protein form a complex that acts as a protein scaffold for integrating signalling pathways and regulating postsynaptic structure [1].** Forced reload

1: Structural basis for asymmetric association of the betaPIX coiled coil and shank PDZ. Im YJ, Kang GB, Lee JH, Park KR, Song HE, Kim E, Song WK, Park D, Eom SH; J Mol Biol. 2010;397:457-466. PMID:20117114