4H6X:
reference: Structures of cyanobactin maturation enzymes define a family of transamidating proteases., Agarwal V, Pierce E, McIntosh J, Schmidt EW, Nair SK, Chem Biol. 2012 Nov 21;19(11):1411-22. doi: 10.1016/j.chembiol.2012.09.012. PMID: 23177196

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