3LGI:
reference: Allostery is an intrinsic property of the protease domain of DegS: implications for enzyme function and evolution., Sohn J, Grant RA, Sauer RT, J Biol Chem. 2010 Oct 29;285(44):34039-47. Epub 2010 Aug 24. PMID: 20739286

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