The ligand-binding domain of the AMPA (alpha-amino-3-hydroxyl-5-methyl-4-isoxazolepropionic acid) subtype GluR2 of ionotropic glutamate receptors, a member of the type 2 periplasmic binding fold protein superfamily.
This group contains the ligand-binding domain of the AMPA receptor subunit GluR2, a member of non-NMDA (N-methyl-D-aspartate) type iGluRs which are ligand-gated ion channels that mediate excitatory synaptic transmission in the central nervous system. While this ligand-binding domain is structurally homologous to the periplasmic-binding fold type II superfamily, the N-terminal domain of AMPA receptors belongs to the periplasmic-binding fold type I. The AMPA receptors are the most commonly found receptor in the nervous system and sensitive to the artificial glutamate analog, AMPA. They consist of four types of subunits (GluR1, GluR2, GluR3, and GluR4) which combine to form a tetramer and play an important role in mediating the rapid excitatory synaptic current.