4EAM:
reference: Designing Allosteric Control into Enzymes by Chemical Rescue of Structure., Deckert K, Budiardjo SJ, Brunner LC, Lovell S, Karanicolas J, J Am Chem Soc. 2012 Jun 11. PMID: 22655749

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