JukAB was shown to be active against nucleus-like forming Jumbo phages :ref{doi=10.1038/s41586-022-05013-4} in *Pseudomonas aeruginosa* :ref{doi=10.1101/2022.09.17.508391}. This system was named JukAB for **Ju**mbo phage **K*iller.
JukAB is composed of two protein JukA and JukB. JukA encode for the DUF3944 domain present in other potential defense system according to :ref{doi=10.1101/2022.09.17.508391}.
## Molecular mechanism
JukAB is acting at the early stage of PhiKZ infection before the phage forms its nucleus.
Using fluorescence microscopy, the authors showed that JukA is acting as a sensor of the phage infection using PhiKZ ejection factors :ref{doi=10.1101/2022.09.17.508391}. After the detection of the infection by JukA, JukB is recruted and the phage
