Butters_gp30_gp31

Description

The anti-phage defense system Butters_gp30_gp31 is encoded in the genomes of Actinobacteria, including in prophages. It was experimentally validated in the host Mycobacterium smegmatis and displayed resistance against phages PurpleHaze and Alma.

Molecular mechanism

To our knowledge, the mechanism of action remains unknown. However, the proteins of this system are predicted as a cytoplasmic protein (gp30) and a 4-pass transmembrane protein (gp31). The proposed mechanism of action is hypothesized to resemble the RexA/B system of coliphage Lambda, where activation of gp30 by phage infection stimulates the ion channel gp31 which causes membrane depolarization and loss of intracellular ATP, which in turn, causes abortive infection.

Example of genomic structure

The Butters_gp30_gp31 is composed of 2 proteins: Butters_gp30 and Butters_gp31.

Here is an example found in the RefSeq database:

The Butters_gp30_gp31 system in Snodgrassella alvi (GCF_022870965.1, NZ_CP091515) is composed of 2 proteins Butters_gp31 (WP_025330184.1) CarolAnn_gp44 (WP_144353282.1)

Distribution of the system among prokaryotes

Structure

Experimental validation

      
graph LR;
    Mageeney_2020[Mageeney et al., 2020] --> Origin_0
    Origin_0[Mycobacterium phage Butters 
YP_007869841.1, YP_007869842.1] --> Expressed_0[Mycobacterium smegmatis]
    Expressed_0[Mycobacterium smegmatis] ----> PurpleHaze
    Expressed_0[Mycobacterium smegmatis] ----> Alma
    subgraph Title1[Reference]
        Mageeney_2020
end
    subgraph Title2[System origin]
        Origin_0
end
    subgraph Title3[Expression species]
        Expressed_0
end
    subgraph Title4[Protects against]
        PurpleHaze
        Alma
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