1ELC:
reference: Analogous inhibitors of elastase do not always bind analogously., Mattos C, Rasmussen B, Ding X, Petsko GA, Ringe D, Nat Struct Biol 1994 Jan;1(1):55-8. PMID: 7656008

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