6H3J:
reference: Type 9 secretion system structures reveal a new protein transport mechanism., Lauber F, Deme JC, Lea SM, Berks BC, Nature. 2018 Dec;564(7734):77-82. doi: 10.1038/s41586-018-0693-y. Epub 2018 Nov, 7. PMID: 30405243

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