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| | ==Quisqualate bound to the D655A mutant of the ligand binding domain of GluA3== | | ==Quisqualate bound to the D655A mutant of the ligand binding domain of GluA3== |
| - | <StructureSection load='4f2q' size='340' side='right' caption='[[4f2q]], [[Resolution|resolution]] 2.20Å' scene=''> | + | <StructureSection load='4f2q' size='340' side='right'caption='[[4f2q]], [[Resolution|resolution]] 2.20Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4f2q]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Buffalo_rat Buffalo rat]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4F2Q OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4F2Q FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4f2q]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4F2Q OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4F2Q FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=QUS:(S)-2-AMINO-3-(3,5-DIOXO-[1,2,4]OXADIAZOLIDIN-2-YL)-PROPIONIC+ACID'>QUS</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=QUS:(S)-2-AMINO-3-(3,5-DIOXO-[1,2,4]OXADIAZOLIDIN-2-YL)-PROPIONIC+ACID'>QUS</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4f1y|4f1y]], [[4f22|4f22]], [[4f29|4f29]], [[4f2o|4f2o]], [[4f31|4f31]], [[4f39|4f39]], [[4f3b|4f3b]], [[4f3g|4f3g]]</td></tr>
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4f2q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4f2q OCA], [https://pdbe.org/4f2q PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4f2q RCSB], [https://www.ebi.ac.uk/pdbsum/4f2q PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4f2q ProSAT]</span></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">Glur3, Gria3, Gria3; GluA3 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10116 Buffalo rat])</td></tr>
| + | |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4f2q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4f2q OCA], [http://pdbe.org/4f2q PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4f2q RCSB], [http://www.ebi.ac.uk/pdbsum/4f2q PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4f2q ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/GRIA3_RAT GRIA3_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 (By similarity). | + | [https://www.uniprot.org/uniprot/GRIA3_RAT GRIA3_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 (By similarity). |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </div> | | </div> |
| | <div class="pdbe-citations 4f2q" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 4f2q" style="background-color:#fffaf0;"></div> |
| | + | |
| | + | ==See Also== |
| | + | *[[Glutamate receptor 3D structures|Glutamate receptor 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Buffalo rat]] | + | [[Category: Large Structures]] |
| - | [[Category: Ahmed, A H]] | + | [[Category: Rattus norvegicus]] |
| - | [[Category: Oswald, R E]] | + | [[Category: Ahmed AH]] |
| - | [[Category: Ampa receptor]] | + | [[Category: Oswald RE]] |
| - | [[Category: Glua3]]
| + | |
| - | [[Category: Glur3]]
| + | |
| - | [[Category: Glutamate receptor]]
| + | |
| - | [[Category: Lbd]]
| + | |
| - | [[Category: Neurotransmitter receptor]]
| + | |
| - | [[Category: Quisqualate]]
| + | |
| - | [[Category: S1s2]]
| + | |
| - | [[Category: Transport protein-agonist complex]]
| + | |
| Structural highlights
Function
GRIA3_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 (By similarity).
Publication Abstract from PubMed
Ligand-gated ion channels undergo conformational changes that transfer the energy of agonist binding to channel opening. Within ionotropic glutamate receptor (iGluR) subunits, this process is initiated in their bilobate ligand binding domain (LBD) where agonist binding to lobe 1 favors closure of lobe 2 around the agonist and allows formation of interlobe hydrogen bonds. AMPA receptors (GluAs) differ from other iGluRs because glutamate binding causes an aspartate-serine peptide bond in a flexible part of lobe 2 to rotate 180 degrees (flipped conformation), allowing these residues to form cross-cleft H-bonds with tyrosine and glycine in lobe 1. This aspartate also contacts the side chain of a lysine residue in the hydrophobic core of lobe 2 by a salt bridge. We investigated how the peptide flip and electrostatic contact (D655-K660) in GluA3 contribute to receptor function by examining pharmacological and structural properties with an antagonist (CNQX), a partial agonist (kainate), and two full agonists (glutamate and quisqualate) in the wildtype and two mutant receptors. Alanine substitution decreased the agonist potency of GluA3(i)-D655A and GluA3(i)-K660A receptor channels expressed in HEK293 cells and differentially affected agonist binding affinity for isolated LBDs without changing CNQX affinity. Correlations observed in the crystal structures of the mutant LBDs included the loss of the D655-K660 electrostatic contact, agonist-dependent differences in lobe 1 and lobe 2 closure, and unflipped D(A)655-S656 bonds. Glutamate-stimulated activation was slower for both mutants, suggesting that efficient energy transfer of agonist binding within the LBD of AMPA receptors requires an intact tether between the flexible peptide flip domain and the rigid hydrophobic core of lobe 2.
The loss of an electrostatic contact unique to AMPA receptor ligand binding domain 2 slows channel activation.,Holley SM, Ahmed AH, Srinivasan J, Murthy SE, Weiland GA, Oswald RE, Nowak LM Biochemistry. 2012 May 15;51(19):4015-27. Epub 2012 May 2. PMID:22512472[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Holley SM, Ahmed AH, Srinivasan J, Murthy SE, Weiland GA, Oswald RE, Nowak LM. The loss of an electrostatic contact unique to AMPA receptor ligand binding domain 2 slows channel activation. Biochemistry. 2012 May 15;51(19):4015-27. Epub 2012 May 2. PMID:22512472 doi:10.1021/bi3001837
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