PfiAT

Contributors: Helena Shomar, Marie Guillaume, Florian Tesson

Description

PfiAT is a toxin-antitoxin system discovered in 2020 () .

The role of PfiAT as an antiphage system is not certain and might be removed from DefenseFinder. This system is known to inhibit the Pf4 prophage from Pseudomonas aeruginosa.

The PfiAT system is composed of two small proteins: the antitoxin PfiA and the toxin PfiT.

Molecular mechanism

The PfiAT system acts as a regulator of the Pf4 prophages () . The PfiAT complex will autorepress its own locus.

In the absence of PfiT, PfiA is not able to bind to the promotor. This change leads to the expression of xisF4 and PA0727 leading to the phage replication and excretion.

Example of genomic structure

The PfiAT is composed of 2 proteins: PfiA and PfiT. The PfiAT is composed of 2 proteins: PfiA and PfiT.

Here is an example found in the RefSeq database: Here is an example found in the RefSeq database:

The PfiAT system in Desulfoscipio gibsoniae (GCF_000233715.2, NC_021184) is composed of 2 proteins PfiA (WP_006521270.1) PfiT (WP_006521271.1) The PfiAT system in Desulfoscipio gibsoniae (GCF_000233715.2, NC_021184) is composed of 2 proteins PfiA (WP_006521270.1) PfiT (WP_006521271.1)

Distribution of the system among prokaryotes

Among the 22,803 complete genomes of RefSeq, the PfiAT is detected in 819 genomes (3.59 %). Among the 22,803 complete genomes of RefSeq, the PfiAT is detected in 819 genomes (3.59 %).

The system was detected in 308 different species. The system was detected in 308 different species.

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

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

Structure

PfiAT

Example 1
Example 1

Experimental validation

To our knowledge, no experimental validation of this toxin-antitoxin system exists. It was shown to regulate the replication and expression of the prophage Pf4.

References

10.1111/1751-7915.13570
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