Bacteria use a propeller-shaped “molecular motor” called flagellum to swim and attach to surfaces they infect. It has very intricate machinery, composed of over 25 different proteins, and it is an essential organelle that allows bacteria to infect a host. Yet, most of the molecular details of the flagellum, and its assembly, remain poorly understood.

In recent years, cryo-Electron Microscopy (cryo-EM) has taken the world of molecular biology by storm, as it provides the unprecedented capacity to determine the shape of proteins with atomic-level accuracy. In this recent study, Natalie Al-Otaibi, a PhD student in Dr Bergeron’s team, in collaboration with colleagues at the University of Sheffield and the University of Washington, used cryo-EM to characterise the component of the flagellum called the cap complex, which sits at the very tip of the machinery and is required for its successful assembly. This allowed the research team to propose how this cap complex allows the assembly of the flagellum, at the molecular level.

By understanding how the flagellum works with atomic-level accuracy, scientists could design drugs that prevent its assembly or vaccines that target it for immune response. This would open up new avenues for therapeutics against bacterial infections.

Read the paper in Nature Communications