Bacterial motors carefully studied Archaea included (Introduction)

by David Turell , Sunday, October 02, 2022, 17:58 (571 days ago) @ David Turell

A comparison between bacterial flagella and Archaea's

https://www.sciencedaily.com/releases/2022/09/220927111326.htm

"It has been known that the propeller in bacteria is quite different than similar propellers used by hearty one-celled organisms called archaea. Archaea are found in some of the most extreme environments on Earth, such as in nearly boiling pools of acid, the very bottom of the ocean and in petroleum deposits deep in the ground.

"Using cryo-EM, Egelman and his team found that the protein that makes up the flagellum can exist in 11 different states. It is the precise mixture of these states that causes the corkscrew shape to form.

"Egelman and colleagues used cryo-EM to examine the flagella of one form of archaea, Saccharolobus islandicus, and found that the protein forming its flagellum exists in 10 different states. While the details were quite different than what the researchers saw in bacteria, the result was the same, with the filaments forming regular corkscrews. They conclude that this is an example of "convergent evolution" -- when nature arrives at similar solutions via very different means. This shows that even though bacteria and archaea's propellers are similar in form and function, the organisms evolved those traits independently.

"'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," said Egelman,"

Comment: it is not surprising that the flagella of bacteria and Archaea are similar. Similar
solutions abound in evolution.