AbiB

Contributors: Nathalie Bechon

Description

AbiB is a single-protein abortive infection defense system from Lactococcus that degrades mRNA.

Molecular mechanism

AbiB system is still poorly understood. It is a single-protein system that was described as an abortive infection system. Upon phage infection, AbiB activation leads to a strong degradation of mRNAs () which is expected to be the mechanism of phage inhibition. AbiB expression is constitutive and does increase during phage infection. It is only activated during phage infection, most likely through the recognition of an early phage protein. Which protein, and whether this activation is direct or indirect remains to be elucidated.

Example of genomic structure

The AbiB is composed of 1 protein: AbiB.

Here is an example found in the RefSeq database:

The AbiB system in Lactococcus cremoris (GCF_000312685.1, NC_019430) is composed of 1 protein: AbiB (WP_144019851.1)

Distribution of the system among prokaryotes

Among the 22,803 complete genomes of RefSeq, the AbiB is detected in 11 genomes (0.05 %).

The system was detected in 5 different species.

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

Structure

AbiB

Example 1

Experimental validation

      
graph LR;
    Chopin_2005[Chopin et al., 2005] --> Origin_0
    Origin_0[lactococcal plasmid 
AAA25158.1] --> Expressed_0[lactococci]
    Expressed_0[lactococci] ----> 936
    subgraph Title1[Reference]
        Chopin_2005
end
    subgraph Title2[System origin]
        Origin_0
end
    subgraph Title3[Expression species]
        Expressed_0
end
    subgraph Title4[Protects against]
        936
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

10.1023/A:1002027321171
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10.1016/j.mib.2005.06.006
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10.1128/aem.57.12.3547-3551.1991
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10.1046/j.1365-2958.1996.371896.x
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