6NHL:
reference: Crystal structure of AdoMet radical enzyme 7-carboxy-7-deazaguanine synthase from Escherichia coli suggests how modifications near [4Fe-4S] cluster engender flavodoxin specificity., Grell TAJ, Bell BN, Nguyen C, Dowling DP, Bruender NA, Bandarian V, Drennan CL, Protein Sci. 2019 Jan;28(1):202-215. doi: 10.1002/pro.3529. PMID: 30341796

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