GAPS4

Description

GAPS4 is a two genes system (GAPS4a and GAPS4b). GAPS stands for GMT-encoded Anti-Phage System.

GAPS4 is present in both Gram-positive and Gram-negative GAPS4 activity was assessed in E. coli and was shown to be active against T4, P1-vir and lambda-vir and to reduce lysis plaque size of T7 (N/A) .

Molecular mechanism

GAPS4a is a nuclease containing a domain from the PDDEXK clan (CL0236) suggesting that the GAPS4 defense system is acting via DNA degradation. Both genes are required for phage defense and were predicted to form a heterodimer. It was shown that the system causes host DNA degradation upon infection by lambda-vir only, which would suggest that GAPS4 is an abortive infection system (N/A) .

Example of genomic structure

The GAPS4 is composed of 2 proteins: GAPS4a and GAPS4b.

Here is an example found in the RefSeq database:

The GAPS4 system in Hafnia alvei (GCF_902387815.1, NZ_LR699008) is composed of 2 proteins GAPS4a (WP_111329122.1) GAPS4b (WP_111329123.1)

Distribution of the system among prokaryotes

Structure

Experimental validation

      
graph LR;
    Mahata_2023[Mahata et al., 2023] --> Origin_0
    Origin_0[Vibrio parahaemolyticus 
WP_055466293.1, WP_055466294.1] --> Expressed_0[Escherichia coli]
    Expressed_0[Escherichia coli] ----> T7 & T4 & P1-vir & Lambda-vir
    subgraph Title1[Reference]
        Mahata_2023
end
    subgraph Title2[System origin]
        Origin_0
end
    subgraph Title3[Expression species]
        Expressed_0
end
    subgraph Title4[Protects against]
        T7
        T4
        P1-vir
        Lambda-vir
end
    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