PDBsum entry 1b8q

Oxidoreductase

PDB id: 1b8q

Contents

Protein chain

127 a.a. *

Ligands

VAL-VAL-LYS-VAL-ASP-SER-VAL

* Residue conservation analysis

PDB id:

1b8q

Name:

Oxidoreductase

Title:

Solution structure of the extended neuronal nitric oxide synthase pdz domain complexed with an associated peptide

Structure:

Protein (neuronal nitric oxide synthase). Chain: a. Fragment: pdz domain. Engineered: yes. Protein (heptapeptide). Chain: b. Engineered: yes

Source:

Rattus norvegicus. Norway rat. Organism_taxid: 10116. Expressed in: escherichia coli. Expression_system_taxid: 562. Synthetic: yes

NMR struc:

15 models

Authors:

H.Tochio,Q.Zhang,P.Mandal,M.Li,M.Zhang

Key ref:

H.Tochio et al. (1999). Solution structure of the extended neuronal nitric oxide synthase PDZ domain complexed with an associated peptide. Nat Struct Biol, 6, 417-421. PubMed id: 10331866 DOI: 10.1038/8216

Date:

01-Feb-99 Release date: 29-Apr-99

Protein chain

P02618  (PRVB_CYPCA) -  Parvalbumin beta from Cyprinus carpio

Seq: 108 a.a.

Struc: 127 a.a.*

* PDB and UniProt seqs differ at 60 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.1.14.13.39 - nitric-oxide synthase (NADPH).
• Reaction: 2 L-arginine + 3 NADPH + 4 O2 + H⁺ = 2 L-citrulline + 2 nitric oxide + 3 NADP⁺ + 4 H2O

2 × L-arginine + 3 × NADPH (Bound ligand (Het Group name = LYS) matches with 50.00% similarity) + 4 × O2 + H(+) = 2 × L-citrulline + 2 × nitric oxide + 3 × NADP(+) + 4 × H2O

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1038/8216

Nat Struct Biol 6:417-421 (1999)

PubMed id: 10331866

Solution structure of the extended neuronal nitric oxide synthase PDZ domain complexed with an associated peptide.

H.Tochio, Q.Zhang, P.Mandal, M.Li, M.Zhang.

ABSTRACT

The PDZ domain of neuronal nitric oxide synthase (nNOS) functions as a scaffold for organizing the signal transduction complex of the enzyme. The NMR structure of a complex composed of the nNOS PDZ domain and an associated peptide suggests that a two-stranded beta-sheet C-terminal to the canonical PDZ domain may mediate its interaction with the PDZ domains of postsynaptic density-95 and alpha-syntrophin. The structure also provides the molecular basis of recognition of Asp-X-Val-COOH peptides by the nNOS PDZ domain. The role of the C-terminal extension in Asp-X-Val-COOH peptide binding is investigated. Additionally, NMR studies further show that the Asp-X-Val-COOH peptide and a C-terminal peptide from a novel cytosolic protein named CAPON bind to the same pocket of the nNOS PDZ domain.

Selected figure(s)

Figure 1.
Figure 1. a, Stereoview showing the best-fit superposition of the backbone atoms (N, C , and C') of the final 15 structures of the nNOS PDZ−MelR peptide complex. The structures are superimposed against the average structure using the residues 14−98. The MelR peptide (VVKVDSV) is shown in pink. The -strands in the C-terminal extension are in orange, and the rest of the extension is in cyan. b, Superposition of the 15 NMR structures using the 'I and 'II showing the defined structure of the C-terminal extension of the nNOS PDZ domain. c, Ribbon diagram of the nNOS PDZ−MelR peptide complex. The secondary structural elements of the canonical nNOS PDZ domain are labeled following the scheme of the crystal structure of the PSD-95 PDZ domain^7. The MelR peptide is shown in pink, and the C-terminal extension is in yellow. The two C-terminal strands are named 'I and 'II, respectively.

Figure 4.
Figure 4. Model for nNOS signal transduction complex organization by PDZ domains. The NMDA receptors are clustered by multiple PDZ domain containing PSD-95. The multimeric PSD-95 further couples nNOS to the NMDA receptors, allowing direct activation of nNOS by influxes of Ca^2+. The PDZ domain of nNOS can further recruit its binding protein such as CAPON by binding to its C-terminal tail. The PTB domain of CAPON may bind to as yet unknown NPXpY motif containing proteins in the signaling pathway.

The above figures are reprinted by permission from Macmillan Publishers Ltd: Nat Struct Biol (1999, 6, 417-421) copyright 1999.

Figures were selected by an automated process.