3IWT:
reference: Structure of hypothetical Mo-cofactor biosynthesis protein B (ST2315) from Sulfolobus tokodaii., Antonyuk SV, Strange RW, Ellis MJ, Bessho Y, Kuramitsu S, Shinkai A, Yokoyama S, Hasnain SS, Acta Crystallogr Sect F Struct Biol Cryst Commun. 2009 Dec 1;65(Pt, 12):1200-3. Epub 2009 Nov 27. PMID: 20054111

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