1GED:
reference: A positively charged cluster formed in the heme-distal pocket of cytochrome P450nor is essential for interaction with NADH., Kudo T, Takaya N, Park SY, Shiro Y, Shoun H, J Biol Chem 2001 Feb 16;276(7):5020-6. PMID: 11076941

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