The ligand-binding domain of ionotropic glutamate receptor family, a member of the periplasmic binding protein type II superfamily.
This subfamily represents the ligand binding of ionotropic glutamate receptors. iGluRs are heterotetrameric ion channels that comprises of three functionally distinct subtypes based on their pharmacology and structural similarities: AMPA (alpha-amino-3-hydroxyl-5-methyl-4-isoxazolepropionic acid), NMDA (N-methyl-D-aspartate), and kainate receptors. All three types of channels are also activated by the physiological neurotransmitter, glutamate. iGluRs are concentrated at postsynaptic sites, where they exert a variety of different functions. While this ligand-binding domain of iGluRs is structurally homologous to the periplasmic binding fold type II superfamily, the N-terminal leucine/isoleucine/valine-binding protein (LIVBP)-like domain belongs to the periplasmic-binding fold type I.