Phages overcome bacterial immunity via diverse anti-defence proteins. (https://www.nature.com/articles/s41586-023-06869-w)

These scientists were studying how bacteria protect themselves from viruses called phages. They found that bacteria have different ways to defend themselves, like using a system called CRISPR-Cas and another system called restriction systems. However, the scientists wanted to know how the phages are able to fight against these defenses.

To figure this out, the scientists looked at a group of similar phages that were sensitive to the bacterial defense systems. They discovered four different families of proteins that can stop the bacterial defenses. These proteins are called Gad1, Gad2, Tad2, and Had1.

When these proteins are added to the phages or when they are made by the bacteria together with their defense systems, they can cancel out the defenses. They found that many other phages that infect different types of bacteria also have similar proteins that can disable the defenses.

For example, one of the proteins called Gad1 can stop the defense system called Gabija from cutting the phage's DNA. Another protein called Tad2 acts like a sponge and absorbs the signals that the defense system called Thoeris sends out when it detects a phage.

In conclusion, the scientists discovered that phages have their own set of proteins that can disable different types of bacterial defenses. This helps the phages to infect the bacteria more easily.

Yirmiya E., Leavitt A., Lu A., Ragucci AE., Avraham C., Osterman I., Garb J., Antine SP., Mooney SE., Hobbs SJ., Kranzusch PJ., Amitai G., Sorek R. Phages overcome bacterial immunity via diverse anti-defence proteins. Nature. 2024 Jan;625(7994):352-359. doi: 10.1038/s41586-023-06869-w. Epub 2023 Nov 22.