4IO2

Crystal Structure of the AvGluR1 ligand binding domain complex with glutamate at 1.37 Angstrom resolution

Summary for 4IO2

• Entry DOI: 10.2210/pdb4io2/pdb
• Related: 4IO3 4IO4 4IO5 4IO6 4IO7 4IO8
• Descriptor: Glutamate receptor 1, CHLORIDE ION, GLUTAMIC ACID, ... (4 entities in total)
• Functional Keywords: membrane protein
• Biological source: Adineta vaga (Rotifer); More
• Total number of polymer chains: 2
• Total formula weight: 55420.98

Authors

Lomash, S.,Chittori, S.,Mayer, M.L. (deposition date: 2013-01-07, release date: 2013-02-20, Last modification date: 2024-11-27)

Primary citation

Lomash, S.,Chittori, S.,Brown, P.,Mayer, M.L.
Anions Mediate Ligand Binding in Adineta vaga Glutamate Receptor Ion Channels.
Structure, 21:414-425, 2013

PubMed Abstract: AvGluR1, a glutamate receptor ion channel from the primitive eukaryote Adineta vaga, is activated by alanine, cysteine, methionine, and phenylalanine, which produce lectin-sensitive desensitizing responses like those to glutamate, aspartate, and serine. AvGluR1 LBD crystal structures reveal an unusual scheme for binding dissimilar ligands that may be utilized by distantly related odorant/chemosensory receptors. Arginine residues in domain 2 coordinate the γ-carboxyl group of glutamate, whereas in the alanine, methionine, and serine complexes a chloride ion acts as a surrogate ligand, replacing the γ-carboxyl group. Removal of Cl(-) lowers affinity for these ligands but not for glutamate or aspartate nor for phenylalanine, which occludes the anion binding site and binds with low affinity. AvGluR1 LBD crystal structures and sedimentation analysis also provide insights into the evolutionary link between prokaryotic and eukaryotic iGluRs and reveal features unique to both classes, emphasizing the need for additional structure-based studies on iGluR-ligand interactions.

PubMed: 23434404
DOI: 10.1016/j.str.2013.01.006

Experimental method

X-RAY DIFFRACTION (1.37 Å)