3U99:
reference: High-resolution crystal structure of the recombinant diheme cytochrome c from Shewanella baltica (OS155)., De March M, Di Rocco G, Hickey N, Geremia S, J Biomol Struct Dyn. 2014 Feb 21. PMID: 24559494

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