Contributors: Florian Tesson


JukAB was shown to be active against nucleus-like forming Jumbo phages () in Pseudomonas aeruginosa () . This system was named JukAB for Jumbo phage Killer.

JukAB is composed of two proteins JukA and JukB. JukA encodes for the DUF3944 domain present in other potential defense systems according to () .

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 () . After the detection of the infection by JukA, JukB is recruited and the phage is not able to form its nucleus-like particle and other nuclease from the host will degrade the phage DNA.

The authors () hypothesized that JukA detects the "rod-like" inner body. JukA will recruit JukB which destabilizes the early protective structure of PhiKZ. The accessible DNA will then be degraded by other nucleases.

Example of genomic structure

The JukAB is composed of 2 proteins: JukA and JukB.

Here is an example found in the RefSeq database:

The JukAB system in Kosakonia oryzae (GCF_020544365.1, NZ_CP065358) is composed of 2 proteins JukA (WP_064562651.1) JukB (WP_064562654.1)

Distribution of the system among prokaryotes

Among the 22,803 complete genomes of RefSeq, the JukAB is detected in 133 genomes (0.58 %).

The system was detected in 50 different species.

Proportion of genome encoding the JukAB system for the 14 phyla with more than 50 genomes in the RefSeq database.



Example 1

Experimental validation

graph LR;
    Li_2022[Li et al., 2022] --> Origin_0
    Origin_0[Pseudomonas aeruginosa 
WP_003137195.1, WP_003137196.1] --> Expressed_0[Pseudomonas aeruginosa]
    Expressed_0[Pseudomonas aeruginosa] ----> ΦΚZ
    subgraph Title1[Reference]
    subgraph Title2[System origin]
    subgraph Title3[Expression species]
    subgraph Title4[Protects against]
    style Title1 fill:none,stroke:none,stroke-width:none
    style Title2 fill:none,stroke:none,stroke-width:none
    style Title3 fill:none,stroke:none,stroke-width:none
    style Title4 fill:none,stroke:none,stroke-width:none



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