3MMC:
reference: Structure of the dissimilatory sulfite reductase from the hyperthermophilic archaeon Archaeoglobus fulgidus., Schiffer A, Parey K, Warkentin E, Diederichs K, Huber H, Stetter KO, Kroneck PM, Ermler U, J Mol Biol. 2008 Jun 20;379(5):1063-74. Epub 2008 May 20. PMID: 18495156

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