1MMO:
reference: Crystal structure of a bacterial non-haem iron hydroxylase that catalyses the biological oxidation of methane., Rosenzweig AC, Frederick CA, Lippard SJ, Nordlund P, Nature 1993 Dec 9;366(6455):537-43. PMID: 8255292

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