1ii5

<StructureSection load='1ii5' size='340' side='right' caption='[[1ii5]], [[Resolution|resolution]] 1.60&Aring;' scene=''>

<table><tr><td colspan='2'>[[1ii5]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Syny3 Syny3]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1II5 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1II5 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GLU:GLUTAMIC+ACID'>GLU</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1iit|1iit]], [[1iiw|1iiw]]</td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">GluR0 slr1257, slr1257 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1111708 SYNY3])</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=1ii5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ii5 OCA], [http://pdbe.org/1ii5 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1ii5 RCSB], [http://www.ebi.ac.uk/pdbsum/1ii5 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1ii5 ProSAT]</span></td></tr>

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ii/1ii5_consurf.spt"</scriptWhenChecked>

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== Publication Abstract from PubMed ==

High-resolution structures of the ligand binding core of GluR0, a glutamate receptor ion channel from Synechocystis PCC 6803, have been solved by X-ray diffraction. The GluR0 structures reveal homology with bacterial periplasmic binding proteins and the rat GluR2 AMPA subtype neurotransmitter receptor. The ligand binding site is formed by a cleft between two globular alpha/beta domains. L-Glutamate binds in an extended conformation, similar to that observed for glutamine binding protein (GlnBP). However, the L-glutamate gamma-carboxyl group interacts exclusively with Asn51 in domain 1, different from the interactions of ligand with domain 2 residues observed for GluR2 and GlnBP. To address how neutral amino acids activate GluR0 gating we solved the structure of the binding site complex with L-serine. This revealed solvent molecules acting as surrogate ligand atoms, such that the serine OH group makes solvent-mediated hydrogen bonds with Asn51. The structure of a ligand-free, closed-cleft conformation revealed an extensive hydrogen bond network mediated by solvent molecules. Equilibrium centrifugation analysis revealed dimerization of the GluR0 ligand binding core with a dissociation constant of 0.8 microM. In the crystal, a symmetrical dimer involving residues in domain 1 occurs along a crystallographic 2-fold axis and suggests that tetrameric glutamate receptor ion channels are assembled from dimers of dimers. We propose that ligand-induced conformational changes cause the ion channel to open as a result of an increase in domain 2 separation relative to the dimer interface.

 

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== References ==

[[Category: Syny3]]

[[Category: Gouaux, E]]

[[Category: Mayer, M L]]

[[Category: Olson, R]]

[[Category: Membrane protein]]