Figure 3.

NR3 ligands bind in the cleft between domains 1 and 2. (A) Electron density map (2mFo−DFc contoured at 2σ) for the ligand binding site of the NR3A glycine complex and three water molecules at 1.58 Å resolution. (B) Electron density map (2mFo−DFc contoured at 2σ) for the ligand binding site of the NR3B D-serine complex at 1.62 Å resolution. (C) Stereo view of the NR3A glycine and D-serine complexes superimposed by least squares using domain 1 Cα coordinates; carbon atoms for the ligand and side chains for the glycine and D-serine complexes are shaded grey and green, respectively. (D) Stereo view of the NR3A and NR1 glycine complexes superimposed by least squares using domain 1 Cα coordinates; side chains for NR3A and NR1 are drawn with carbon atoms shaded grey and tan respectively; water molecules in the NR3A and NR1 structures are coloured red and green; dashed lines show hydrogen bonds and are coloured black and green for NR3A and NR1, respectively.