<p>Nature Microbiology, Published online: 03 February 2026; <a href="https://www.nature.com/articles/s41564-026-02275-w">doi:10.1038/s41564-026-02275-w</a></p>A near-complete model for the complex structure of the Campylobacter jejuni flagellar motor revealed different mechanisms of assembly, activation and stability from the simple ‘classical’ flagellar model. Some of the additional motor structures in C. jejuni are conserved and only found in species of Campylobacterota, whose ancestor likely co-opted type IV pilus components from bacteria in the deep ocean.