5CVR:
reference: The crystal structure of the global anaerobic transcriptional regulator FNR explains its extremely fine-tuned monomer-dimer equilibrium., Volbeda A, Darnault C, Renoux O, Nicolet Y, Fontecilla-Camps JC, Sci Adv. 2015 Dec 4;1(11):e1501086. doi: 10.1126/sciadv.1501086. eCollection 2015, Dec. PMID: 26665177

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