FS_Sma

Contributors: Héloïse Georjon

Description

SMA (single-protein MazF-like antiphage system) was identified in a phage-inducible chromosomal island (PICI) found in Staphylococcus aureus () . SMA was shown to inhibit phage infection and to inhibit the formation of new virions after prophage induction.

Molecular mechanisms

The SMA protein comprises a domain analogous to MazF. MazF is a protein that is normally part of the MazEF toxin-antitoxin systems, in which MazF is a toxic endoribonuclease that targets mRNA () . As far as we are aware, the precise molecular mechanism of SMA is unknown.

Example of genomic structure

The Sma is composed of 1 protein: Sma.

Here is an example found in the RefSeq database:

The Sma system in Staphylococcus aureus (GCF_022869625.1, NZ_CP064365) is composed of 1 protein: Sma (WP_000041883.1)

Distribution of the system among prokaryotes

Among the 22,803 complete genomes of RefSeq, the Sma is detected in 578 genomes (2.53 %).

The system was detected in 20 different species.

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

Structure

FS_Sma

Example 1

Experimental validation

      
graph LR;
    Fillol-Salom_2022[Fillol-Salom et al., 2022] --> Origin_0
    Origin_0[Staphylococcus aureus' PICI SaPIpT1028 
RXS01985.1] --> Expressed_0[Staphylococcus aureus]
    Expressed_0[Staphylococcus aureus] ----> 80alpha & phiNM1 & phiNM2 & phi53 & phi55 & phi6199 & phi7206 & phi6490 & phiSLT & Sushi & phi2339 & phi96 & ROSA & phi11 & phi12 & phi85 & phi7094 & phiSA2
    subgraph Title1[Reference]
        Fillol-Salom_2022
end
    subgraph Title2[System origin]
        Origin_0
end
    subgraph Title3[Expression species]
        Expressed_0
end
    subgraph Title4[Protects against]
        80alpha
        phiNM1
        phiNM2
        phi53
        phi55
        phi6199
        phi7206
        phi6490
        phiSLT
        Sushi
        phi2339
        phi96
        ROSA
        phi11
        phi12
        phi85
        phi7094
        phiSA2
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

    

References

10.1016/j.cell.2022.07.014
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10.1016/s1097-2765(03)00402-7
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