The “Rapunzel” virus has a giant tail. we finally know how

Leonora Martinez-Nunez

Illustration of the P74-26

The “Rapunzel” virus has the longest tail of any known virus, and strangely, the most stable as well.

A recent study published in the Journal of Biological Chemistry has revealed the secret behind an evolutionary marvel: a bacteriophage with a extremely long tail. A bacteriophage, better known for just i do It is an acellular being belonging to the group of viruses, which only infects bacteria.

The virus in question is called p74-26, although it is more colloquially known as the virus “Rapunzel”. The name refers to the life story of the young woman with long golden hair, imprisoned at the top of a tower by a witch. The story was adapted for the cinema by Disney, in 2010, in the film “Tangled”.

Just like the character in the stories, the P74-26 has a tail that stands out from the rest. Almost a micrometer long, the tail is ten times longer than most other phages, writes ScienceAlert. It has the longest tail of any known virus, and strangely, the most stable as well.

Comparison of the tail of P74-26 with that of another phage.

The virus lives in inhospitable hot springs and feeds on some of the most resistant bacteria on the planet, such as Thermus thermophilus. The tails of these viruses are important for piercing the bacteria. It is precisely the tail of the “Rapunzel” virus that allows it to invade and infect the most resistant microorganisms.

Scientists have now unraveled the unique structure of P74-26’s tail. Computer simulations revealed a “highly intertwined network of interactions” that coordinate to build the tail.

“By taking lots of pictures of the phage tail tubes and compiling them, we were able to figure out exactly how the building blocks fit together,” explains microbiologist Emily Agnello, lead author of the new study.

Agnello and his colleagues wanted to understand how the virus managed to survive in such extreme environments. The thermal waters reach temperatures of over 77°C.

“Each phage tail is composed of many small building blocks that come together to form a long tube. Our study found that these building blocks can change shape as they come together.”

Biochemist Brian Kelch, co-author of the study, says the research team thinks what happened to P74-26 is that some ancient virus fused its building blocks into a protein.

“Imagine two small Lego blocks merged into one big brick seamless. This long tail is built with larger, sturdier building blocks. We think this could stabilize the tail at high temperatures,” explained the scientist.

Although the size of the tail of the “Rapunzel” virus gives it great power to penetrate bacteria, it also makes the tail assembly more likely to go wrong. Scientists believe the virus has internal mechanisms that keep the developing tail on track.

Daniel Costa, ZAP //