Experts Solve Decades-Old Mystery About Bacteria


| LAST UPDATE 09/29/2022

By Daria Appleby
Bacteria Movement Flagellum Mystery
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Bacteria is most commonly known as an unhealthy "microbe," or germ that no one wants to have contact with. However, the unruly truth is that bacteria are everywhere and are here to stay. And while not all bacteria are harmful, experts finally cracked the 50-year mystery of how and why they move.

A group of researchers from the University of Virginia School of Medicine has recently solved a decades-old mystery about how E. coli and other forms of bacteria can move. Bacteria can be seen as "threadlike" but are also classified into five shapes; spherical, rod, spiral, comma, and corkscrew. The different shapes act as "makeshift propellers," but the mystery continues as scientists question how this occurs. Considering these specific "propellers" are made up of a single protein, how can bacteria move around? Team leader at UVA, Edward H. Egelman, Ph.D., a "leader in the field of high-tech cryo-electron microscopy, has used state-of-the-art technology to understand this concept. Using cryo-EM and "advanced computer modeling to reveal what no traditional light microscope could see."

Cryo-EM Technology Bacteria Research
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So, what did Egelman find? He noted, "while models have existed for 50 years for how these filaments might form such regular coiled shapes, we have now determined the structure of these filaments in atomic detail." He added, "we can show that these models were wrong, and our new understanding will help pave the way for technologies that could be based upon such miniature propellers." Egelman further investigated the "blueprints for bacteria's supercoils." He established the different configurations of bacteria have many "appendages known as a flagellum, or, in the plural, flagella." The flagellum is made up of "thousands of subunits" that are all the same. If they weren't, the bacteria would not be able to move. With the push from a propeller, the bacteria can move forward and shape into a "supercoiling" formation. Egelman and his team found the protein in the flagellum can form 11 different states that comprise the corkscrew shape, causing movements. Egelman supported his findings by experimenting on another one-celled organism, archaea. This is found in extreme Earth environments such as acid pools and deep underground. The team examined flagella in "one form of archaea" and found it exists in 10 different states, resulting in the same corkscrew formation causing movement. They established this as "convergent evolution," proving the same independent traits are formed in different organisms, that being, in this case, bacteria and archaea propellers.

Egelman backed up his findings, "as with birds, bats, and bees, which have all independently evolved wings for flying, the evolution of bacteria and archaea has converged on a similar solution for swimming in both." While these formations and bacterial structured were formed billions of years ago, 50 years to establish these findings seems rather swift. Stay tuned for more breaking news.