AbiQ was discovered in 1998 on *Lactococcus lactis* plasmid :ref{doi=10.1128/AEM.64.12.4748-4756.1998}.
AbiQ is one of the so-called "Abi" systems for "Abortive infection" discovered in the 90's in research related to the dairy industry :ref{doi=10.1016/j.mib.2005.06.006}. AbiQ is classified as abortive infection in :ref{doi=10.1016/j.mib.2023.102312}.
AbiQ is composed of a single protein AbiQ and an RNA antitoxin (antiQ) :ref{doi=10.1111/mmi.12129}.
## Molecular mechanism
AbiQ act as an anti-toxin type III. AbiQ is an RNAase that will bind its antitoxin antiQ :ref{doi=10.1111/mmi.12129}.
The AbiQ is constitutively expressed and bind to its antiQ RNA resulting in an inactivated AbiQ.
To get activated, AbiQ needs the concentration of antiQ to decrease.
However, during phage infection, the expression of the antiQ is constant and the authors do not know how the AbiQ is activated :ref{doi=10.1111/mmi.12129}.
## Example of genomic structure
## Example of genomic structure
The AbiQ is composed of 1 protein: AbiQ.
The AbiQ is composed of 1 protein: AbiQ.
...
@@ -38,6 +58,18 @@ The system was detected in 111 different species.
...
@@ -38,6 +58,18 @@ The system was detected in 111 different species.
Proportion of genome encoding the AbiQ system for the 14 phyla with more than 50 genomes in the RefSeq database.
Proportion of genome encoding the AbiQ system for the 14 phyla with more than 50 genomes in the RefSeq database.
## Structure
### Experimentally determined structure
From :ref{doi=10.1111/mmi.12129} in *Lactococcus lactis*: