3VFZ:
reference: Mycobacterium tuberculosis RsdA provides a conformational rationale for selective regulation of sigma-factor activity by proteolysis., Jaiswal RK, Prabha TS, Manjeera G, Gopal B, Nucleic Acids Res. 2013 Jan 11. PMID: 23314154

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