Skip to main content
. Author manuscript; available in PMC: 2020 Jun 30.
Published in final edited form as: Methods Mol Biol. 2017;1677:1–80. doi: 10.1007/978-1-4939-7321-7_1

Figure 6. Subunit crossover and symmetry mismatch in the NMDA receptor structure.

Figure 6.

Side view of the GluN1/2B NMDA receptor structure (PDB ID 4PE5; [67]) and top views of the ATD, LBD, and TMD layers. The subunits in GluN1/2 receptors are arranged in an alternating pattern (i.e. 1-2-1-2) and there is a symmetry mismatch between the TMDs and the extracellular LBDs and ATDs of the receptor. The TMDs are arranged symmetrically around the ion channel pore with a quasi-4-fold symmetry, whereas the extracellular portion adopts a dimer-of-dimer arrangement (i.e. two GluN1/2 heterodimers) with a 2-fold symmetry. There is a subunit crossover between the LBD layer and the ATD layer in that the GluN1(α) ATD forms a local dimer with the GluN2B(α) ATD, whereas the GluN1(α) LBD forms a local dimer with the GluN2B(β) LBD.