Single proton torque generation in <i>Escherichia coli</i>

Escherichia coli (E. coli) is an unicellular microorganism that lives in human intestines. The locomotion of this bacteria is powered by one or more long bacterial flagellar motors, ~ 45 nm molecular nano machines. The bacterial flagellar motor, which converts a proton-motive force to flagellar rotation, plays an important role in various biological phenomena such as chemotaxis, cell swarming over a surface, and bacterial pathogenicity. It also attracts a growing interest as a framework for a potential target for drug development countering human disease. However, despite its biological significance, the mechanism that underlies the torque generation of the bacterial flagallar motor still remains elusive. Our preliminary results show that single proton may be enough to generate torque of the bacterial flagellar motors.