1MIO:
reference: X-ray crystal structure of the nitrogenase molybdenum-iron protein from Clostridium pasteurianum at 3.0-A resolution., Kim J, Woo D, Rees DC, Biochemistry 1993 Jul 20;32(28):7104-15. PMID: 8393705

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