Scientists found out how the virus that infects bacteria comes together. This virus has a really long tail and it lives in hot springs, where it feeds on special kinds of bacteria that are hard to survive in those harsh conditions. A study was recently published about this in the Journal of Biological Chemistry.
Bacteriophages are viruses that infect and grow in bacteria, and they are the most common creatures on Earth. Emily Agnello, a graduate student at the University of Massachusetts Chan Medical School said “Phages (short for Bacteriophages) are pretty much everywhere you can find bacteria – like dirt, water, or even inside your body”.
Phages are different from most other viruses that affect humans and animals because they have a tail connected to an egg-shaped protein shell which holds their DNA.
Phage tails, just like the kind of hairstyle someone has, come in different lengths and shapes. Most phages have short tail that can only be seen under a microscope, but the “Rapunzel Bacteriophage” P74-26 has super long one – it’s about 10 times bigger than other phage tails, and nearly 1 micrometer long! That’s really thin – which is actually close to the width of some spider webs. The name “Rapunzel” comes from an old fairytale where there was a girl with extremely long hair locked in a tower by an evil witch.
Brian Kelch, a professor at UMass Chan who oversaw the work, said that P74-26 had an “extremely long tail”.
P74-26 is an incredibly special virus. It has a very long tail that helps it break into tough bacteria, like those found in extremely hot water – up to 170° F! That makes P74-26 one of the most stable viruses around. Scientists want to know how it can survive in such extreme conditions, so they’re studying it in labs.
To work with the phage that likes hot temperatures, Agnello had to change her experiment conditions so the phage tail could build itself in a test tube. Kelch said that Agnello made a way to make the tail thing quickly build itself.
Scientists discovered that the parts which make up a phage tail (which is like a long tube) can change how they look. This helps these parts fit together correctly to build the right shape of the tail.
The researchers looked really closely at the parts of a tail using special tools and computers and realized that these tiny components are propping each other up in order to remain stable.
We used a special microscope called Cryo-electron Microscopy which helps us to take lots of high-quality pictures and short videos. We were able to spot how the parts fit together for a phage’s tail tubes through these pictures.
Scientists just discovered that P74-26 can fix itself up using something similar to Lego blocks. The tail is made of many little rings stacked together like a hollow tube. Kinda cool how this virus looks like it’s building itself with Legos!
It’s like Lego pieces – where when you begin to build with them, the holes start opening up so you can join more pieces together. This is an important way for the parts of phages (a type of virus) to come together and form what they need. Professor Kelch also said that P74-26 needs fewer building blocks than most other phages in order to create their tails.
Kelch told us that an old virus has combined its separate parts into one big piece, which is like two small Lego bricks being pushed together to form a single, solid block. This longer tail of the virus is built with larger and sturdier pieces and this makes it able to remain intact even at higher temperatures.
The researchers are now trying something new: they will use genetic changes to affect the size of the tail of the virus to observe how that may alter its behavior.
Phages exist nearly everywhere and have many uses. For example, they are used in healthcare and food safety, plus help conserve the environment. A type of long-tailed phages called P74-26 has even been tried in medicine to fight off certain bacterial diseases.
“Scientists are very interested in using special viruses called bacteriophages instead of antibiotics to treat bacterial infections,” Agnello explained. “By studying how phages interact with bacteria, we can figure out ways to create better treatments with these viruses. Studying these kinds of topics could lead to some incredible discoveries in the future.”
Reference: “Conformational dynamics control assembly of an extremely long bacteriophage tail tube” by Emily Agnello, Joshua Pajak, Xingchen Liu and Brian A. Kelch, 14 March 2023, Journal of Biological Chemistry.
DOI: 10.1016/j.jbc.2023.103021
