Figure 2. Asymmetric ATD and ATD-LBD interfaces.
Surface and cartoon representations of the GluN1/GluN2A (A) and GluN1/GluN2B (B) heterodimers of the non-Ro-bound state, viewed parallel to the membrane. GluN1/GluN2A and GluN1/GluN2B ATDs are highlighted in black frame (C-D), showing interaction of GluN2A ATD and GluN2B ATD with the LBD layer, respectively. The Cα atoms of several key residues in the ATD-LBD crevice are shown as spheres, and distances between Cα atoms are indicated (Å). (E-F) Superimposition of GluN1/GluN2A and GluN1/GluN2B ATD heterodimers using the R1 lobe of GluN1 subunits. The relative rotations of the R2 lobes as well as the COM of R2 lobes are indicated. (G) Superimposition of GluN2A and GluN2B ATDs using their R1 lobes illustrates the clamshell closure of GluN2A ATD. The relative rotation of their R2 lobes, as well as the distances between the COM of R1 and R2 lobes, are indicated.