1SGC:
reference: The 1.8 A structure of the complex between chymostatin and Streptomyces griseus protease A. A model for serine protease catalytic tetrahedral intermediates., Delbaere LT, Brayer GD, J Mol Biol 1985 May 5;183(1):89-103. PMID: 3892018

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