3NUH:
reference: A domain insertion in Escherichia coli GyrB adopts a novel fold that plays a critical role in gyrase function., Schoeffler AJ, May AP, Berger JM, Nucleic Acids Res. 2010 Jul 31. PMID: 20675723

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