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Publication Abstract from PubMed

Zinc 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^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.