3CRF:
reference: Structural analysis of the Saf pilus by electron microscopy and image processing., Salih O, Remaut H, Waksman G, Orlova EV, J Mol Biol. 2008 May 23;379(1):174-87. Epub 2008 Apr 3. PMID: 18448124

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