A bacteriophage (bacteria-infecting virus) called P74-26 and nicknamed ‘Rapunzel bacteriophage’ lives in inhospitable hot springs and preys on Thermus thermophilus, one of the toughest bacteria on the planet.
Bacteriophages are ubiquitous viruses that selectively and specifically infect their bacterial host.
The overwhelming majority of phages belong to the order Caudovirales, which consist of a capsid that contains the double-stranded DNA genome, and a tail.
The tail is essential for host recognition and viral attachment, and therefore successful infections.
“Bacteriophages, or phages for short, are everywhere that bacteria are, including the dirt and water around you and in your own body’s microbial ecosystem as well,” said Emily Agnello, a graduate student at the University of Massachusetts Chan Medical School.
While most phages have short, microscopic tails, P74-26 has a tail 10 times longer than most and is nearly 1 micrometer long, about the width of some spider’s silk.
Not only does P74-26 have an extremely long tail, but it is also the most stable phage, allowing it to exist in and infect bacteria that live in hot springs.
“Each phage tail is made up of many small building blocks that come together to form a long tube,” Agnello said.
“Our research finds that these building blocks can change shape, or conformation, as they come together.”
“This shape-changing behavior is important in allowing the building blocks to fit together and form the correct structure of the tail tube.”
The researchers used high-power imaging techniques as well as computer simulations and found that the building blocks of the tail lean on each other to stabilize themselves.
“We used a technique called cryo-electron microscopy, which is a huge microscope that allows us to take thousands of images and short movies at a very high magnification,” Agnello said.
“By taking lots of pictures of the phage’s tail tubes and stacking them together, we were…
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