View source for 3kei


==Crystal Structure of the GluA4 Ligand-Binding domain L651V mutant in complex with glutamate==
<StructureSection load='3kei' size='340' side='right'caption='[[3kei]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3kei]] 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=3KEI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3KEI 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]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=3kei FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3kei OCA], [https://pdbe.org/3kei PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3kei RCSB], [https://www.ebi.ac.uk/pdbsum/3kei PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3kei ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GRIA4_RAT GRIA4_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).<ref>PMID:12603841</ref> <ref>PMID:19102704</ref> <ref>PMID:20107073</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ke/3kei_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3kei ConSurf].
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== Publication Abstract from PubMed ==
AMPA receptors (AMPARs) are tetrameric ligand-gated ion channels that couple the energy of glutamate binding to the opening of a transmembrane channel. Crystallographic and electrophysiological analysis of AMPARs has suggested a coupling between (1) cleft closure in the bilobate ligand-binding domain (LBD), (2) the resulting separation of transmembrane helix attachment points across subunit dimers, and (3) agonist efficacy. In general, more efficacious agonists induce greater degrees of cleft closure and transmembrane separation than partial agonists. Several apparent violations of the cleft-closure/efficacy paradigm have emerged, although in all cases, intradimer separation remains as the driving force for channel opening. Here, we examine the structural basis of partial agonism in GluA4 AMPARs. We find that the L651V substitution enhances the relative efficacy of kainate without increasing either LBD cleft closure or transmembrane separation. Instead, the conformational change relative to the wild-type:kainate complex involves a twisting motion with the efficacy contribution opposite from that expected based on previous analyses. As a result, channel opening may involve transmembrane rearrangements with a significant rotational component. Furthermore, a two-dimensional analysis of agonist-induced GluA2 LBD motions suggests that efficacy is not a linearly varying function of lobe 2 displacement vectors, but is rather determined by specific conformational requirements of the transmembrane domains.

Enhanced efficacy without further cleft closure: reevaluating twist as a source of agonist efficacy in AMPA receptors.,Birdsey-Benson A, Gill A, Henderson LP, Madden DR J Neurosci. 2010 Jan 27;30(4):1463-70. PMID:20107073<ref>PMID:20107073</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 3kei" 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: Gill A]]
[[Category: Madden DR]]