4GRS:
reference: Engineering allosteric control to an unregulated enzyme by transfer of a regulatory domain., Cross PJ, Allison TM, Dobson RC, Jameson GB, Parker EJ, Proc Natl Acad Sci U S A. 2013 Jan 23. PMID: 23345433

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