View source for 4bdm


==Crystal structure of the GluK2 K531A LBD dimer in complex with kainate==
<StructureSection load='4bdm' size='340' side='right'caption='[[4bdm]], [[Resolution|resolution]] 3.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4bdm]] is a 4 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=4BDM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4BDM 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]] 3.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=KAI:3-(CARBOXYMETHYL)-4-ISOPROPENYLPROLINE'>KAI</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=4bdm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4bdm OCA], [https://pdbe.org/4bdm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4bdm RCSB], [https://www.ebi.ac.uk/pdbsum/4bdm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4bdm 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 ==
Gating of AMPA- and kainate-selective ionotropic glutamate receptors can be defined in terms of ligand affinity, efficacy and the rate and extent of desensitization. Crucial insights into all three elements have come from structural studies of the ligand-binding domain (LBD). In particular, binding-cleft closure is associated with efficacy, whereas dissociation of the dimer formed by neighbouring LBDs is linked with desensitization. We have explored these relationships in the kainate-selective subunit GluK2 by studying the effects of mutating two residues (K531 and R775) that form key contacts within the LBD dimer interface, but whose truncation unexpectedly attenuates desensitization. One mutation (K531A) also switches the relative efficacies of glutamate and kainate. LBD crystal structures incorporating these mutations revealed several conformational changes that together explain their phenotypes. K531 truncation results in new dimer contacts, consistent with slower desensitization and sideways movement in the ligand-binding cleft correlating with efficacy. The tested mutants also disrupted anion binding; no chloride was detected in the dimer-interface site, including in R775A where absence of chloride was the only structural change evident. From this, we propose that the charge balance in the GluK2 LBD dimer interface maintains a degree of instability, necessary for rapid and complete desensitization.

Correlating efficacy and desensitization with GluK2 ligand-binding domain movements.,Nayeem N, Mayans O, Green T Open Biol. 2013 May 29;3(5):130051. doi: 10.1098/rsob.130051. PMID:23720540<ref>PMID:23720540</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 4bdm" 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]]