5ikb
From Proteopedia
Crystal structure of the kainate receptor GluK4 ligand binding domain in complex with kainate
Structural highlights
FunctionGRIK4_RAT Receptor for glutamate. L-glutamate acts as an excitatory neurotransmitter at many synapses in the central nervous system. The postsynaptic actions of Glu are mediated by a variety of receptors that are named according to their selective agonists. This receptor binds kainate > quisqualate > glutamate >> AMPA. Publication Abstract from PubMedIonotropic glutamate receptors play a key role in fast neurotransmission in the CNS and have been linked to several neurological diseases and disorders. One subfamily is the kainate receptors, which are grouped into low-affinity (GluK1-3) and high-affinity (GluK4-5) receptors based on their affinity for kainate. Although structures of the ligand-binding domain (LBD) of all low-affinity kainate receptors have been reported, no structures of the high-affinity receptor subunits are available. Here, we present the X-ray structure of GluK4-LBD with kainate at 2.05 A resolution, together with thermofluor and radiolabel binding affinity data. Whereas binding-site residues in GluK4 are most similar to the AMPA receptor subfamily, the domain closure and D1-D2 interlobe contacts induced by kainate are similar to the low-affinity kainate receptor GluK1. These observations provide a likely explanation for the high binding affinity of kainate at GluK4-LBD. The Structure of a High-Affinity Kainate Receptor: GluK4 Ligand-Binding Domain Crystallized with Kainate.,Kristensen O, Kristensen LB, Mollerud S, Frydenvang K, Pickering DS, Kastrup JS Structure. 2016 Sep 6;24(9):1582-9. doi: 10.1016/j.str.2016.06.019. Epub 2016 Aug, 11. PMID:27524200[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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