5ESC:
reference: In vitro heme biotransformation by the HupZ enzyme from Group A streptococcus., Sachla AJ, Ouattara M, Romero E, Agniswamy J, Weber IT, Gadda G, Eichenbaum Z, Biometals. 2016 May 6. PMID: 27154580

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