1BIQ:
reference: Crystal structures of two self-hydroxylating ribonucleotide reductase protein R2 mutants: structural basis for the oxygen-insertion step of hydroxylation reactions catalyzed by diiron proteins., Logan DT, deMare F, Persson BO, Slaby A, Sjoberg BM, Nordlund P, Biochemistry 1998 Jul 28;37(30):10798-807. PMID: 9692970

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