6GMS:
reference: Structure and Assembly of the Enterohemorrhagic Escherichia coli Type 4 Pilus., Bardiaux B, de Amorim GC, Luna Rico A, Zheng W, Guilvout I, Jollivet C, Nilges M, Egelman EH, Izadi-Pruneyre N, Francetic O, Structure. 2019 Apr 9. pii: S0969-2126(19)30117-0. doi:, 10.1016/j.str.2019.03.021. PMID: 31056419

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