3HIO:
reference: Transition state analogues in structures of ricin and saporin ribosome-inactivating proteins., Ho MC, Sturm MB, Almo SC, Schramm VL, Proc Natl Acad Sci U S A. 2009 Dec 1;106(48):20276-81. Epub 2009 Nov 17. PMID: 19920175

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