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Scientists View Bacterial Protein Channels with Cryo-EM to Elucidate Their Method of Function
Almost all bacteria rely on the same emergency valves--protein channels that pop open under pressure, releasing a deluge of cell contents. It is a last-ditch effort, a failsafe that prevents bacteria from exploding and dying when stretched to the limit. If we understood how these protein channels worked, antibiotic drugs could be designed to open them on demand, draining a bacterium of its nutrients by exploiting a floodgate common to many species. But these channels are tricky to operate in the lab. And how precisely they open and close, passing through a sub-conducting state and ending in a desensitized state under the influence of mechanical forces, remains poorly understood. Now, new research from the laboratory of Rockefeller University’s Thomas Walz, PhD, Professor of Biochemistry, Biophysics, Chemical Biology, and Structural Biology, introduces a novel method to activate and visualize these channels, making it possible to explain their function. The findings shed light on key membrane proteins in bacteria, and the same method can be used to improve our understanding of similar channels in humans. The results were published online on February 10, 2021 in Nature. The article is titled “Visualization of the Mechanosensitive Ion Channel MscS Under Membrane Tension” (https://www.nature.com/articles/s41586-021-03196-w). "We were actually able to see the entire cycle of the protein channel passing through a series of functional stages," Dr. Walz says.