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1mm6
From Proteopedia
crystal structure of the GluR2 ligand binding core (S1S2J) in complex with quisqualate in a non zinc crystal form at 2.15 angstroms resolution
Structural highlights
Function[GRIA2_RAT] Receptor for glutamate that functions as ligand-gated ion channel in the central nervous system and plays an important role in excitatory synaptic transmission. L-glutamate acts as an excitatory neurotransmitter at many synapses in the central nervous system. Binding of the excitatory neurotransmitter L-glutamate induces a conformation change, leading to the opening of the cation channel, and thereby converts the chemical signal to an electrical impulse. The receptor then desensitizes rapidly and enters a transient inactive state, characterized by the presence of bound agonist. In the presence of CACNG4 or CACNG7 or CACNG8, shows resensitization which is characterized by a delayed accumulation of current flux upon continued application of glutamate.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedGlutamate is the major excitatory neurotransmitter in the mammalian brain. The (S)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazole)propionic acid (AMPA)-subtype glutamate receptor, a ligand-gated ion channel, mediates most of the fast excitatory synaptic transmission in the mammalian central nervous system. Here we present electrophysiological, biochemical, and crystallographic data on the interactions between quisqualate and the GluR2 receptor ion channel and its corresponding ligand binding core. Quisqualate is a high-affinity, full agonist which like AMPA and glutamate elicits maximum peak current responses, and stabilizes the ligand binding core in a fully closed conformation, reinforcing the concept that full agonists produce similar conformational changes [Armstrong, N., and Gouaux, E. (2000) Neuron 28, 165-181]. Nevertheless, the mechanism of quisqualate binding is different from that of AMPA but similar to that of glutamate, illustrating that quisqualate is a faithful glutamate analogue. A detailed comparison of the three agonist complexes reveals distinct binding mechanisms, particularly in the region of a hydrophobic pocket that is proximal to the anionic gamma-substituents, and demonstrates the importance of agonist-water-receptor interactions. The hydrophobic pocket, which is predicted to vary in chemical character between receptor subtypes, probably plays an important role in determining receptor subtype specificity. Mechanism of activation and selectivity in a ligand-gated ion channel: structural and functional studies of GluR2 and quisqualate.,Jin R, Horning M, Mayer ML, Gouaux E Biochemistry. 2002 Dec 31;41(52):15635-43. PMID:12501192[15] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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