6GUI:
reference: Iron scavenging in Aspergillus species: Structural and biochemical insights into fungal siderophore esterases., Ecker F, Haas H, Groll M, Huber E, Angew Chem Int Ed Engl. 2018 Aug 1. doi: 10.1002/anie.201807093. PMID: 30070018

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