1RYC:
reference: A ligand-gated, hinged loop rearrangement opens a channel to a buried artificial protein cavity., Fitzgerald MM, Musah RA, McRee DE, Goodin DB, Nat Struct Biol 1996 Jul;3(7):626-31. PMID: 8673607

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