Pif

Description

The Pif system (Phage Inhibition by F factors) was first described by Morisson & Malamy (N/A) . The Pif region of the F plasmid inhibits the phage T7 through abortive infection (N/A, N/A) .

Molecular mechanisms

PifA was later identified as the effector of the abortive infection (N/A, N/A) through nucleotide depletion by increased membrane permeability (also known as "leakage").

Example of genomic structure

The Pif is composed of 2 proteins: PifA and PifC.

Here is an example found in the RefSeq database:

The Pif system in Shigella flexneri (GCF_022353545.1, NZ_CP055168) is composed of 2 proteins PifC (WP_000952217.1) PifA (WP_000698737.1)

Distribution of the system among prokaryotes

Structure

Experimental validation

      
graph LR;
    Cheng_2004[Cheng et al., 2004] --> Origin_0
    Origin_0[Escherichia coli F-plasmid 
WP_028985935.1, WP_028985936.1] --> Expressed_0[Escherichia coli]
    Expressed_0[Escherichia coli] ----> T7
    subgraph Title1[Reference]
        Cheng_2004
end
    subgraph Title2[System origin]
        Origin_0
end
    subgraph Title3[Expression species]
        Expressed_0
end
    subgraph Title4[Protects against]
        T7
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