3S8K:
reference: The plasticity of the beta-trefoil fold constitutes an evolutionary platform for protease inhibition., Azarkan M, Martinez-Rodriguez S, Buts L, Baeyens-Volant D, Garcia-Pino A, J Biol Chem. 2011 Dec 23;286(51):43726-34. Epub 2011 Oct 25. PMID: 22027836

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