1n7f

Publication Abstract from PubMed

PDZ domains bind to short segments within target proteins in a sequence-specific fashion. Glutamate receptor-interacting protein (GRIP)/ABP family proteins contain six to seven PDZ domains and interact via the sixth PDZ domain (class II) with the C termini of various proteins including liprin-alpha. In addition the PDZ456 domain mediates the formation of homo- and heteromultimers of GRIP proteins. To better understand the structural basis of peptide recognition by a class II PDZ domain and PDZ-mediated multimerization, we determined the crystal structures of the GRIP1 PDZ6 domain alone and in complex with a synthetic C-terminal octapeptide of human liprin-alpha at resolutions of 1.5 and 1.8 A, respectively. Remarkably, unlike other class II PDZ domains, Ile-736 at alphaB5 rather than conserved Leu-732 at alphaB1 makes a direct hydrophobic contact with the side chain of the Tyr at the -2 position of the ligand. Moreover, the peptide-bound structure of PDZ6 shows a slight reorientation of helix alphaB, indicating that the second hydrophobic pocket undergoes a conformational adaptation to accommodate the bulkiness of the Tyr side chain, and forms an antiparallel dimer through an interface located at a site distal to the peptide-binding groove. This configuration may enable formation of GRIP multimers and efficient clustering of GRIP-binding proteins.

Crystal structure of GRIP1 PDZ6-peptide complex reveals the structural basis for class II PDZ target recognition and PDZ domain-mediated multimerization.,Im YJ, Park SH, Rho SH, Lee JH, Kang GB, Sheng M, Kim E, Eom SH J Biol Chem. 2003 Mar 7;278(10):8501-7. Epub 2002 Dec 18. PMID:12493751^[1]

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