4RKN:
reference: The octahaem MccA is a haem c-copper sulfite reductase., Hermann B, Kern M, La Pietra L, Simon J, Einsle O, Nature. 2015 Feb 2. doi: 10.1038/nature14109. PMID: 25642962

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