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1qlc
From Proteopedia
SOLUTION STRUCTURE OF THE SECOND PDZ DOMAIN OF POSTSYNAPTIC DENSITY-95
Overview
The second PDZ domain of postsynaptic density-95 (PSD-95 PDZ2) plays a critical role in coupling N-methyl-D-aspartate receptors to neuronal nitric oxide synthase (nNOS). In this work, the solution structure of PSD-95 PDZ2 was determined to high resolution by NMR spectroscopy. The structure of PSD-95 PDZ2 was compared in detail with that of alpha1-syntrophin PDZ domain, as the PDZ domains share similar target interaction properties. The interaction of the PSD-95 PDZ2 with a carboxyl-terminal peptide derived from a cytoplasmic protein CAPON was studied by NMR titration experiments. Complex formation between PSD-95 PDZ2 and the nNOS PDZ was modelled on the basis of the crystal structure of the alpha1-syntrophin PDZ/nNOS PDZ dimer. We found that the prolonged loop connecting the betaB and betaC strands of PSD-95 PDZ2 is likely to play a role in both the binding of the carboxyl-terminal peptide and the nNOS beta-finger. Finally, the backbone dynamics of the PSD-95 PDZ2 in the absence of bound peptide were studied using a model-free approach. The "GLGF"-loop and the loop connecting alphaB and betaF of the protein display some degree of flexibility in solution. The rest of the protein is rigid and lacks detectable slow time-scale (microseconds to milliseconds) motions. In particular, the loop connecting betaB and betaC loop adopts a well-defined, rigid structure in solution. It appears that the loop adopts a pre-aligned conformation for the PDZ domain to interact with its targets.
About this Structure
1QLC is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
Solution structure and backbone dynamics of the second PDZ domain of postsynaptic density-95., Tochio H, Hung F, Li M, Bredt DS, Zhang M, J Mol Biol. 2000 Jan 14;295(2):225-37. PMID:10623522 Page seeded by OCA on Sat May 3 06:24:41 2008
