5tpz
From Proteopedia
Crystal structure of amino terminal domains of the NMDA receptor subunit GluN1 and GluN2B in apo closed state
Structural highlights
FunctionNMDZ1_XENLA Component of NMDA receptor complexes that function as heterotetrameric, ligand-gated ion channels with high calcium permeability and voltage-dependent sensitivity to magnesium. Channel activation requires binding of the neurotransmitter glutamate to the epsilon subunit, glycine binding to the zeta subunit, plus membrane depolarization to eliminate channel inhibition by Mg(2+) (PubMed:16214956, PubMed:19524674, PubMed:21677647, PubMed:25008524, PubMed:26912815, PubMed:27135925, Ref.11, PubMed:28232581). Sensitivity to glutamate and channel kinetics depend on the subunit composition (Probable).[1] [2] [3] [4] [5] [6] [7] [PDB:5IOV] Publication Abstract from PubMedZinc is vastly present in the mammalian brain and controls functions of various cell surface receptors to regulate neurotransmission. A distinctive characteristic of N-methyl-D-aspartate (NMDA) receptors containing a GluN2A subunit is that their ion channel activity is allosterically inhibited by a nano-molar concentration of zinc that binds to an extracellular domain called an amino-terminal domain (ATD). Despite physiological importance, the molecular mechanism underlying the high-affinity zinc inhibition has been incomplete because of the lack of a GluN2A ATD structure. Here we show the first crystal structures of the heterodimeric GluN1-GluN2A ATD, which provide the complete map of the high-affinity zinc-binding site and reveal distinctive features from the ATD of the GluN1-GluN2B subtype. Perturbation of hydrogen bond networks at the hinge of the GluN2A bi-lobe structure affects both zinc inhibition and open probability, supporting the general model in which the bi-lobe motion in ATD regulates the channel activity in NMDA receptors. Molecular Basis for Subtype Specificity and High-Affinity Zinc Inhibition in the GluN1-GluN2A NMDA Receptor Amino-Terminal Domain.,Romero-Hernandez A, Simorowski N, Karakas E, Furukawa H Neuron. 2016 Dec 21;92(6):1324-1336. doi: 10.1016/j.neuron.2016.11.006. Epub 2016, Dec 1. PMID:27916457[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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