1p1q

Crystal structure of the GluR2 ligand binding core (S1S2J) L650T mutant in complex with AMPA

spinqualitylabelsall models 1p1q, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1p1q is a 3 chain structure with sequence from Rattus norvegicus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2Å Ligands: AMQ, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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. 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 PubMed The (S)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazole) propionic acid (AMPA) receptor discriminates between agonists in terms of binding and channel gating; AMPA is a high-affinity full agonist, whereas kainate is a low-affinity partial agonist. Although there is extensive literature on the functional characterization of partial agonist activity in ion channels, structure-based mechanisms are scarce. Here we investigate the role of Leu-650, a binding cleft residue conserved among AMPA receptors, in maintaining agonist specificity and regulating agonist binding and channel gating by using physiological, x-ray crystallographic, and biochemical techniques. Changing Leu-650 to Thr yields a receptor that responds more potently and efficaciously to kainate and less potently and efficaciously to AMPA relative to the WT receptor. Crystal structures of the Leu-650 to Thr mutant reveal an increase in domain closure in the kainate-bound state and a partially closed and a fully closed conformation in the AMPA-bound form. Our results indicate that agonists can induce a range of conformations in the GluR2 ligand-binding core and that domain closure is directly correlated to channel activation. The partially closed, AMPA-bound conformation of the L650T mutant likely captures the structure of an agonist-bound, inactive state of the receptor. Together with previously solved structures, we have determined a mechanism of agonist binding and subsequent conformational rearrangements. Tuning activation of the AMPA-sensitive GluR2 ion channel by genetic adjustment of agonist-induced conformational changes.,Armstrong N, Mayer M, Gouaux E Proc Natl Acad Sci U S A. 2003 May 13;100(10):5736-41. Epub 2003 May 2. PMID:12730367 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Glutamate receptor 3D structures

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