5IAG:
reference: Tunable allosteric library of caspase-3 identifies coupling between conserved water molecules and conformational selection., Maciag JJ, Mackenzie SH, Tucker MB, Schipper JL, Swartz P, Clark AC, Proc Natl Acad Sci U S A. 2016 Oct 11;113(41):E6080-E6088. Epub 2016 Sep 28. PMID: 27681633

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