6DHY:
reference: Determining the structural and energetic basis of allostery in a de novo designed metalloprotein assembly., Churchfield LA, Alberstein RG, Williamson LM, Tezcan FA, J Am Chem Soc. 2018 Jul 12. doi: 10.1021/jacs.8b05812. PMID: 29996654

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