Ultracold snapshots reveals in exquisite detail how a bacterial flagellum rotates

A series of highly detailed images of the structures found in the whirling flagellum that powers a bacterium’s movement has revealed new insights about how microbes get to where they want to be.

Using cryo-electron microscopy (cryo-EM) two different groups have uncovered the molecular architecture of, and interactions between, key components of the bacterial motor that powers bidirectional rotation of the flagellum.

‘The whole concept of chemotaxis is the ability to move away from danger and towards food sources and many bacteria are able to do this via the flagellum … either by changing the direction in which the flagellum rotates or by stopping it completely,’ explains Steven Johnson, staff scientist at the National Cancer Institute (NCI) in the US and lead researcher on one of the studies.