Electron microscope reveals bacteria motor parts

A new study of the exoticMotorsthat bacteria use to swim reveals details of how theySwimthat may make it possible to design specific drugs that sabotage the flagella in targeted bacterial species.

Their visualizations of these motors explain the differences in swimming ability, mathematically accounting for differences in motor power.

The team found that stronger swimmers have evolved by adding extra parts to their motors, making more powerful motors that have increased turning force, or torque.

In flagellar motors, the turning force is produced by a ring of structures called stators around the motor.

Despite motors in diverse bacteria having the same core structure, different bacteria vary widely in their swimming power.

Entire branches of the bacterial family tree have evolved motors with different torques, leading to a diversity of species each geared to their own environment,” said Beeby.

The team is now investigating how and when the evolutionary steps that altered motor torque happened.

Abstract of Diverse high-torque bacterial flagellar motors assemble wider stator rings using a conserved protein scaffold.

For the first time, to our knowledge, our results unambiguously locate the torque-generating stator complexes and show that diverse high-torque motors use variants of an ancestrally related family of structures to scaffold incorporation of additional stator complexes at wider radii from the axial driveshaft than in the model enteric motor.

Our results quantitatively account for different motor torques, complete the assignment of the locations of the major flagellar components, and provide crucial constraints for understanding mechanisms of torque generation and the evolution of multiprotein complexes.

Diverse high-torque bacterial flagellar motors assemble wider stator rings using a conserved protein scaffold.

 

Source – Kurzweil