1JNI:
reference: The 1.25 A resolution structure of the diheme NapB subunit of soluble nitrate reductase reveals a novel cytochrome c fold with a stacked heme arrangement., Brige A, Leys D, Meyer TE, Cusanovich MA, Van Beeumen JJ, Biochemistry 2002 Apr 16;41(15):4827-36. PMID: 11939777

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