1iit: Difference between revisions
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'''GLUR0 LIGAND BINDING CORE COMPLEX WITH L-SERINE''' | {{Structure | ||
|PDB= 1iit |SIZE=350|CAPTION= <scene name='initialview01'>1iit</scene>, resolution 1.90Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=SER:SERINE'>SER</scene> | |||
|ACTIVITY= | |||
|GENE= slr1257 GluR0 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1143 Synechocystis sp.]) | |||
}} | |||
'''GLUR0 LIGAND BINDING CORE COMPLEX WITH L-SERINE''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1IIT is a [ | 1IIT is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Synechocystis_sp. Synechocystis sp.]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IIT OCA]. | ||
==Reference== | ==Reference== | ||
Mechanisms for ligand binding to GluR0 ion channels: crystal structures of the glutamate and serine complexes and a closed apo state., Mayer ML, Olson R, Gouaux E, J Mol Biol. 2001 Aug 24;311(4):815-36. PMID:[http:// | Mechanisms for ligand binding to GluR0 ion channels: crystal structures of the glutamate and serine complexes and a closed apo state., Mayer ML, Olson R, Gouaux E, J Mol Biol. 2001 Aug 24;311(4):815-36. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11518533 11518533] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Synechocystis sp.]] | [[Category: Synechocystis sp.]] | ||
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[[Category: SER]] | [[Category: SER]] | ||
[[Category: membrane protein]] | [[Category: membrane protein]] | ||
[[Category: same fold as | [[Category: same fold as pbp]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:50:57 2008'' | ||
Revision as of 09:51, 20 March 2008
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| 1iit, resolution 1.90Å | |||||||||||||
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| Ligands: | SER | ||||||||||||
| Gene: | slr1257 GluR0 (Synechocystis sp.) | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
GLUR0 LIGAND BINDING CORE COMPLEX WITH L-SERINE
Overview
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.
About this Structure
1IIT is a Single protein structure of sequence from Synechocystis sp.. Full crystallographic information is available from OCA.
Reference
Mechanisms for ligand binding to GluR0 ion channels: crystal structures of the glutamate and serine complexes and a closed apo state., Mayer ML, Olson R, Gouaux E, J Mol Biol. 2001 Aug 24;311(4):815-36. PMID:11518533
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