6WJE:
reference: The bacterial copper-resistance protein CopG contains a cysteine-bridged tetranuclear copper cluster., Hausrath AC, Ramirez NA, Ly AT, McEvoy MM, J Biol Chem. 2020 Jun 22. pii: RA120.013907. doi: 10.1074/jbc.RA120.013907. PMID: 32571874

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