Schematic representation of the conformational changes of the GluN2B subunit between the GluN1-N2B di-eNMDAR and GluN1-N2A-N2B tri-eNMDAR. The subunits are represented with the corresponding colors as in previous figures. The untwisting of GluN2B-NTD, tighter GluN1-N2B NTD, and LBD heterodimer formations through R1-R1 and D1-D1 interfaces, and the approach of GluN1(C)-M3 toward GluN2B-M3, are highlighted by arrows.
