1QLC

Solution structure of the second PDZ domain of Postsynaptic Density-95

Summary for 1QLC

• Entry DOI: 10.2210/pdb1qlc/pdb
• Related: 1BE9 1BFE
• Descriptor: POSTSYNAPTIC DENSITY PROTEIN 95 (1 entity in total)
• Functional Keywords: peptide recognition, pdz domain, neuronal nitric oxide synthase, nmda receptor binding
• Biological source: RATTUS NORVEGICUS (RAT)
• Cellular location: Cell membrane; Peripheral membrane protein: P31016
• Total number of polymer chains: 1
• Total formula weight: 9982.50

Authors

Tochio, H.,Hung, F.,Li, M.,Zhang, M. (deposition date: 1999-08-25, release date: 2000-02-06, Last modification date: 2024-05-15)

Primary citation

Tochio, H.,Hung, F.,Li, M.,Bredt, D.S.,Zhang, M.
Solution Structure and Backbone Dynamics of the Second Pdz Domain of Postsynaptic Density-95
J.Mol.Biol., 295:225-, 2000

PubMed Abstract: 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.

PubMed: 10623522
DOI: 10.1006/JMBI.1999.3350

Experimental method

SOLUTION NMR