PDBsum entry 3en3

Membrane protein

PDB id: 3en3

Contents

Protein chain

257 a.a. *

Ligands

KAI

Waters ×97

* Residue conservation analysis

PDB id:

3en3

Name:

Membrane protein

Title:

Crystal structure of the glur4 ligand-binding domain in complex with kainate

Structure:

Glutamate receptor 4,glutamate receptor. Chain: a. Fragment: ligand binding domain (unp residues 416-528 and 654-958). Synonym: glur-4, glur4, glur-d, glutamate receptor ionotropic, ampa 4, ampa-selective glutamate receptor 4. Engineered: yes

Source:

Rattus norvegicus. Rat. Organism_taxid: 10116. Strain: sprague-dawley. Gene: glur4,glutamate receptor. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.43Å R-factor: 0.159 R-free: 0.219

Authors:

A.Gill,D.R.Madden

Key ref:

A.Gill et al. (2008). Correlating AMPA receptor activation and cleft closure across subunits: crystal structures of the GluR4 ligand-binding domain in complex with full and partial agonists. Biochemistry, 47, 13831-13841. PubMed id: 19102704

Date:

25-Sep-08 Release date: 19-May-09

Protein chain

P19493  (GRIA4_RAT) -  Glutamate receptor 4 from Rattus norvegicus

Seq: 902 a.a.

Struc: 257 a.a.*

* PDB and UniProt seqs differ at 8 residue positions (black crosses)

Biochemistry 47:13831-13841 (2008)

PubMed id: 19102704

Correlating AMPA receptor activation and cleft closure across subunits: crystal structures of the GluR4 ligand-binding domain in complex with full and partial agonists.

A.Gill, A.Birdsey-Benson, B.L.Jones, L.P.Henderson, D.R.Madden.

ABSTRACT

AMPA receptors are glutamate-gated ion channels that are essential mediators of synaptic signals in the central nervous system. They form tetramers that are assembled as combinations of subunits GluR1-4, each of which contains a ligand-binding domain (LBD). Crystal structures of the GluR2 LBD have revealed an agonist-binding cleft, which is located between two lobes and which acts like a Venus flytrap. In general, agonist efficacy is correlated with the extent of cleft closure. However, recent observations show that cleft closure is not the sole determinant of the relative efficacy for glutamate receptors. In addition, these studies have focused on the GluR2 subunit, which is the specific target of a physiologically important RNA-editing modification in vivo. We therefore sought to test the generality of the cleft closure-efficacy correlation for other AMPA-R subunits. Here, we present crystal structures of the GluR4(flip) LBD in complex with both full and partial agonists. As for GluR2, both agonists stabilize a closed-cleft conformation, and the partial agonist induces a smaller cleft closure than the full agonist. However, a detailed analysis of LBD-kainate interactions reveals the importance of subtle backbone conformational changes in the ligand-binding pocket in determining the magnitude of agonist-associated conformational changes. Furthermore, the GluR4 subunit exhibits a different correlation between receptor activation and LBD cleft closure than does GluR2.