View source for 2xxw


==Crystal structure of the GluK2 (GluR6) D776K LBD dimer in complex with glutamate==
<StructureSection load='2xxw' size='340' side='right'caption='[[2xxw]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2xxw]] is a 2 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=2XXW OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2XXW FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=GLU:GLUTAMIC+ACID'>GLU</scene></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=2xxw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2xxw OCA], [https://pdbe.org/2xxw PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2xxw RCSB], [https://www.ebi.ac.uk/pdbsum/2xxw PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2xxw ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GRIK2_RAT GRIK2_RAT] Ionotropic glutamate receptor. 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. May be involved in the transmission of light information from the retina to the hypothalamus. Modulates cell surface expression of NETO2 (By similarity).<ref>PMID:17486098</ref> <ref>PMID:17115050</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
AMPA- and kainate (KA)-selective ionotropic glutamate receptors (iGluRs) respond to agonist by opening (gating), then closing (desensitizing) in quick succession. Gating has been linked to agonist-induced changes within the ligand-binding domain (LBD), and desensitization to rearrangement of a dimer formed by neighboring LBDs. To explore the role of dimer conformation in both gating and desensitization, we compared the conformational effects of two kainate receptor mutants. The first, GluK2-D776K, blocks desensitization of macroscopic current responses ("macroscopic desensitization"). The second, GluK2-M770K, accelerates macroscopic desensitization and eliminates the effects of external ions on channel kinetics. Using structures determined by x-ray crystallography, we found that in both mutants the introduced lysines act as tethered cations, displacing sodium ions from their binding sites within the dimer interface. This results in new inter- and intra-protomer contacts in D776K and M770K respectively, explaining the effects of these mutations on dimer stability and desensitization kinetics. Further, chloride binding was unaffected by the M770K mutation, even though binding of sodium ions has been proposed to promote dimer stability by stabilizing anion binding. This suggests sodium binding may affect receptor function more directly than currently supposed. Notably, we also observed a ligand-specific shift in dimer conformation when comparing LBD dimers in complex with glutamate or the partial agonist KA, revealing a previously unidentified role for dimer orientation in iGluR gating.

Conformational flexibility of the ligand-binding domain dimer in kainate receptor gating and desensitization.,Nayeem N, Mayans O, Green T J Neurosci. 2011 Feb 23;31(8):2916-24. PMID:21414913<ref>PMID:21414913</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2xxw" style="background-color:#fffaf0;"></div>

==See Also==
*[[Glutamate receptor 3D structures|Glutamate receptor 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Rattus norvegicus]]
[[Category: Green T]]
[[Category: Mayans O]]
[[Category: Nayeem N]]