1FKJ:
reference: Comparative X-ray structures of the major binding protein for the immunosuppressant FK506 (tacrolimus) in unliganded form and in complex with FK506 and rapamycin., Wilson KP, Yamashita MM, Sintchak MD, Rotstein SH, Murcko MA, Boger J, Thomson JA, Fitzgibbon MJ, Black JR, Navia MA, Acta Crystallogr D Biol Crystallogr. 1995 Jul 1;51(Pt 4):511-21. PMID: 15299838

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