Structures and activation mechanism of the Gabija anti-phage system. (https://pubmed.ncbi.nlm.nih.gov/38471529/)

These scientists wanted to understand how a group of tiny organisms called prokaryotes defend themselves against viruses called phages. They studied a defense system called Gabija, which has two important parts called GajA and GajB. They used a special technique called cryo-electron microscopy to take detailed pictures of these parts in different states.

They found that GajA is like a shape of a rhombus with different parts inside. When ATP, which is like a fuel for cells, binds to GajA, it keeps a part called the Toprim domain closed. But when the ATP is used up by phages, the Toprim domain opens up to cut the DNA of the phages. GajB, the other part of the defense system, gets activated by the cut DNA and causes the prokaryotic cell to die.

By studying these structures, the scientists were able to understand how the Gabija system gets activated to protect prokaryotes from phages.

Li J., Cheng R., Wang Z., Yuan W., Xiao J., Zhao X., Du X., Xia S., Wang L., Zhu B., Wang L. Structures and activation mechanism of the Gabija anti-phage system. Nature. 2024 Mar 12. doi: 10.1038/s41586-024-07270-x.