3UB1:
reference: The conjugation protein TcpC from Clostridium perfringens is structurally related to the type IV secretion system protein VirB8 from Gram-negative bacteria., Porter CJ, Bantwal R, Bannam TL, Rosado CJ, Pearce MC, Adams V, Lyras D, Whisstock JC, Rood JI, Mol Microbiol. 2012 Jan;83(2):275-88. doi:, 10.1111/j.1365-2958.2011.07930.x. Epub 2011 Dec 11. PMID: 22150951

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