1YKT:
reference: Partially folded bovine pancreatic trypsin inhibitor analogues attain fully native structures when co-crystallized with S195A rat trypsin., Getun IV, Brown CK, Tulla-Puche J, Ohlendorf D, Woodward C, Barany G, J Mol Biol. 2008 Jan 18;375(3):812-23. Epub 2007 Nov 6. PMID: 18054043

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