Toxin-antitoxin systems are widespread in bacteria and archaea. They perform diverse functional roles, including the generation of persistence, maintenance of genetic loci and resistance to bacteriophages through abortive infection. Toxin-antitoxin systems have been divided into three types, depending on the nature of the interacting macromolecules. The recently discovered Type III toxin-antitoxin systems encode protein toxins that are inhibited by pseudoknots of antitoxic RNA, encoded by short tandem repeats upstream of the toxin gene. Recent studies have identified the range of Type I and Type II systems within current sequence databases. Here, structure-based homology searches were combined with iterative protein sequence comparisons to obtain a current picture of the prevalence of Type III systems. Three independent Type III families were identified, according to toxin sequence similarity. The three families were found to be far more abundant and widespread than previously known, with examples throughout the Firmicutes, Fusobacteria and Proteobacteria. Functional assays confirmed that representatives from all three families act as toxin-antitoxin loci within Escherichia coli and at least two of the families confer resistance to bacteriophages. This study shows that active Type III toxin-antitoxin systems are far more diverse than previously known, and suggests that more remain to be identified.
Pharmacology, Toxicology and Pharmaceutical Science
2
<1%
Other
7
3%
Unknown
53
23%
Attention Score in Context
Attention Score in Context
This research output has an Altmetric Attention Score of 5. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 14 August 2025.
All research outputs
#7,468,454
of 26,609,881 outputs
Outputs from Nucleic Acids Research
#12,397
of 28,204 outputs
Outputs of similar age
#46,485
of 173,454 outputs
Outputs of similar age from Nucleic Acids Research
#60
of 184 outputs
Altmetric has tracked 26,609,881 research outputs across all sources so far. This one has received more attention than most of these and is in the 71st percentile.
So far Altmetric has tracked 28,204 research outputs from this source. They typically receive a little more attention than average, with a mean Attention Score of 7.4. This one has gotten more attention than average, scoring higher than 55% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 173,454 tracked outputs that were published within six weeks on either side of this one in any source. This one has gotten more attention than average, scoring higher than 72% of its contemporaries.
We're also able to compare this research output to 184 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 66% of its contemporaries.
