1PB9:
reference: Mechanisms of activation, inhibition and specificity: crystal structures of the NMDA receptor NR1 ligand-binding core., Furukawa H, Gouaux E, EMBO J 2003 Jun 16;22(12):2873-85. PMID: 12805203

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).