4YHB:
reference: Structure and Mechanism of the Siderophore-Interacting Protein from the Fuscachelin Gene Cluster of Thermobifida fusca., Li K, Chen WH, Bruner SD, Biochemistry. 2015 Jun 30;54(25):3989-4000. doi: 10.1021/acs.biochem.5b00354., Epub 2015 Jun 18. PMID: 26043104

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