1CCA:
reference: The Asp-His-Fe triad of cytochrome c peroxidase controls the reduction potential, electronic structure, and coupling of the tryptophan free radical to the heme., Goodin DB, McRee DE, Biochemistry 1993 Apr 6;32(13):3313-24. PMID: 8384877

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