Researchers from the Institut Pasteur and the National Center for Scientific Research in Paris have elucidated the molecular structure of a crossbow-like weapon from bacteria’s arsenal. Ultimately, this could help to fight infectious diseases.
Bacteria are in a constant battle with innumerable other microbes in their environment, so they have to bring in the big guns to survive. A main strategy of them is to inject virulence factors into other bacteria or cells to modify their physiology to their advantage. They do this with a complex molecular machinery, from which the precise architecture remained unknown – until the groups of Eric Cascales and Rémi Fronzes got to the bottom of it.
The machinery in focus is more specifically the bacterial type VI secretion system. The scientific team describes it as resembling a molecular crossbow that propels an arrow into the inner of the target cell, while this “crossbow” is stably attached to the bacterial envelope.
Using high-resolution electron microscopy, the scientists could enlighten that the crossbow-complex is assembled by the addition of three proteins,