4RE5:
reference: Catalytically distinct states captured in a crystal lattice: the substrate-bound and scavenger states of acylaminoacyl peptidase and their implications for functionality., Menyhard DK, Orgovan Z, Szeltner Z, Szamosi I, Harmat V, Acta Crystallogr D Biol Crystallogr. 2015 Mar 1;71(Pt 3):461-72. doi:, 10.1107/S1399004714026819. Epub 2015 Feb 26. PMID: 25760596

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