3C36

Crystal structure of GluR5 ligand-binding core in complex with ammonium ions at 1.68 Angstrom resolution

Summary for 3C36

• Entry DOI: 10.2210/pdb3c36/pdb
• Related: 1TT1 2F34 2OJT 2PBW 3C31 3C32 3C33 3C34 3C35
• Descriptor: GLUTAMATE RECEPTOR, IONOTROPIC KAINATE 1, AMMONIUM ION, CHLORIDE ION, ... (6 entities in total)
• Functional Keywords: membrane protein
• Biological source: Rattus norvegicus (Rat); More
• Cellular location: Cell membrane; Multi-pass membrane protein: P22756
• Total number of polymer chains: 2
• Total formula weight: 59387.76

Authors

Mayer, M.L. (deposition date: 2008-01-27, release date: 2008-06-17, Last modification date: 2023-08-30)

Primary citation

Plested, A.J.,Vijayan, R.,Biggin, P.C.,Mayer, M.L.
Molecular basis of kainate receptor modulation by sodium.
Neuron, 58:720-735, 2008

PubMed Abstract: Membrane proteins function in a polarized ionic environment with sodium-rich extracellular and potassium-rich intracellular solutions. Glutamate receptors that mediate excitatory synaptic transmission in the brain show unusual sensitivity to external ions, resulting in an apparent requirement for sodium in order for glutamate to activate kainate receptors. Here, we solve the structure of the Na(+)-binding sites and determine the mechanism by which allosteric anions and cations regulate ligand-binding dimer stability, and hence the rate of desensitization and receptor availability for gating by glutamate. We establish a stoichiometry for binding of 2 Na(+) to 1 Cl(-) and show that allosteric anions and cations bind at physically discrete sites with strong electric fields, that the binding sites are not saturated in CSF, and that the requirement of kainate receptors for Na(+) occurs simply because other cations bind with lower affinity and have lower efficacy compared to Na(+).

PubMed: 18549784
DOI: 10.1016/j.neuron.2008.04.001

Experimental method

X-RAY DIFFRACTION (1.68 Å)