PDBsum entry 4g8m

Membrane protein/agonist

PDB id: 4g8m

Contents

Protein chains

260 a.a.

Ligands

G8M ×2

SO4 ×7

GOL ×2

Metals

_CL ×3

Waters ×370

PDB id:

4g8m

Name:

Membrane protein/agonist

Title:

Crystal structure of the glua2 ligand-binding domain (s1s2j) in complex with the agonist cbg-iv at 2.05a resolution

Structure:

Glutamate receptor 2. Chain: a, b. Fragment: unp residues 413-527, 653-796. Synonym: glur-2, ampa-selective glutamate receptor 2, glur-b, glur- k2, glutamate receptor ionotropic, ampa 2, glua2. Engineered: yes

Source:

Rattus norvegicus. Brown rat,rat,rats. Organism_taxid: 10116. Strain: rat. Gene: glur2, gria2. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.05Å R-factor: 0.183 R-free: 0.228

Authors:

L.Juknaite,K.Frydenvang,J.S.Kastrup,M.Gajhede

Key ref:

L.Juknaitė et al. (2012). Pharmacological and structural characterization of conformationally restricted (S)-glutamate analogues at ionotropic glutamate receptors. J Struct Biol, 180, 39-46. PubMed id: 22789682

Date:

23-Jul-12 Release date: 08-Aug-12

Protein chains

P19491  (GRIA2_RAT) -  Glutamate receptor 2 from Rattus norvegicus

Seq: 883 a.a.

Struc: 260 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

J Struct Biol 180:39-46 (2012)

PubMed id: 22789682

Pharmacological and structural characterization of conformationally restricted (S)-glutamate analogues at ionotropic glutamate receptors.

L.Juknaitė, R.Venskutonytė, Z.Assaf, S.Faure, T.Gefflaut, D.J.Aitken, B.Nielsen, M.Gajhede, J.S.Kastrup, L.Bunch, K.Frydenvang, D.S.Pickering.

ABSTRACT

Conformationally restricted glutamate analogues have been pharmacologically characterized at AMPA and kainate receptors and the crystal structures have been solved of the ligand (2S,1'R,2'S)-2-(2'-carboxycyclobutyl)glycine (CBG-IV) in complex with the ligand binding domains of the AMPA receptor GluA2 and the kainate receptor GluK3. These structures show that CBG-IV interacts with the binding pocket in the same way as (S)-glutamate. The binding affinities reveal that CBG-IV has high affinity at the AMPA and kainate receptor subtypes. Appreciable binding affinity of CBG-IV was not observed at NMDA receptors, where the introduction of the carbocyclic ring is expected to lead to a steric clash with binding site residues. CBG-IV was demonstrated to be an agonist at both GluA2 and the kainate receptor GluK1. CBG-IV showed high affinity binding to GluK1 compared to GluA2, GluK2 and GluK3, which exhibited lower affinity for CBG-IV. The structure of GluA2 LBD and GluK3 LBD in complex with CBG-IV revealed similar binding site interactions to those of (S)-glutamate. No major conformational rearrangements compared to the (S)-glutamate bound conformation were found in GluK3 in order to accommodate CBG-IV, in contrast with GluA2 where a shift in lobe D2 binding site residues occurs, leading to an increased binding cavity volume compared to the (S)-glutamate bound structure.