PDBsum entry 1qlc

Peptide recognition

PDB id: 1qlc

Contents

Protein chain

95 a.a. *

* Residue conservation analysis

PDB id:

1qlc

Name:

Peptide recognition

Title:

Solution structure of the second pdz domain of postsynaptic density-95

Structure:

Postsynaptic density protein 95. Chain: a. Fragment: the second pdz domain. Synonym: psd-95. Engineered: yes

Source:

Rattus norvegicus. Rat. Organism_taxid: 10116. Expressed in: escherichia coli. Expression_system_taxid: 562

NMR struc:

20 models

Authors:

H.Tochio,F.Hung,M.Li,M.Zhang

Key ref:

H.Tochio et al. (2000). Solution structure and backbone dynamics of the second PDZ domain of postsynaptic density-95. J Mol Biol, 295, 225-237. PubMed id: 10623522 DOI: 10.1006/jmbi.1999.3350

Date:

25-Aug-99 Release date: 06-Feb-00

Protein chain

P31016  (DLG4_RAT) -  Disks large homolog 4 from Rattus norvegicus

Seq: 724 a.a.

Struc: 95 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1006/jmbi.1999.3350

J Mol Biol 295:225-237 (2000)

PubMed id: 10623522

Solution structure and backbone dynamics of the second PDZ domain of postsynaptic density-95.

H.Tochio, F.Hung, M.Li, D.S.Bredt, M.Zhang.

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.

Selected figure(s)

Figure 2.
Figure 2. Stereoview showing the best-fit superposition of the backbone atoms (N, C a , and C0) of the final 20 struc- tures of PSD-95 PDZ2. The structures are superimposed against the average structure using the residues 158-246. The program MOLMOL (Koradi et al., 1996) was used to generate the Figure.

Figure 6.
Figure 6. Model of the PSD-95 PDZ2 and the nNOS PDZ complex. In this model, PSD-95 PDZ2 (green) is superimposed on the a1- syntrophin PDZ domain (red) (Hillier et al., 1999). The nNOS PDZ domain is shown in blue. The Figure was generated using MOL- SCRIPT and Raster3D.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2000, 295, 225-237) copyright 2000.

Figures were selected by an automated process.