5KIL:
reference: A Carboxylate Shift Regulates Dioxygen Activation by the Diiron Nonheme beta-Hydroxylase CmlA upon Binding of a Substrate-Loaded Nonribosomal Peptide Synthetase., Jasniewski AJ, Knoot CJ, Lipscomb JD, Que L Jr, Biochemistry. 2016 Oct 18;55(41):5818-5831. doi: 10.1021/acs.biochem.6b00834., Epub 2016 Oct 7. PMID: 27668828

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