|Description||The bacterial flagellar motor is a molecular machine that can rotate the flagellar
filament at high speed. The rotation is generated by the stator–rotor interaction, coupled with an
ion flux through the torque-generating stator. Here we employed cryo-electron tomography to
visualize the intact flagellar motor in the Lyme disease spirochete, Borrelia burgdorferi. By
analyzing the motor structures of wild-type and stator-deletion mutants, we not only localized the
stator complex in situ, but also revealed the stator–rotor interaction at an unprecedented detail.
Importantly, the stator–rotor interaction induces a conformational change in the flagella C-ring.
Given our observation that a non-motile mutant, in which proton flux is blocked, cannot generate
the similar conformational change, we propose that the proton-driven torque is responsible for the
conformational change required for flagellar rotation.||en_US