DRT stands for Defense-associated Reverse Transcriptases.
DRTs are a widespread and highly diverse family of defense systems, characterized by reverse transcriptase (RTs) components with antiphage properties. These RTs belong to the so-called group of unknown RTs (UG) and are closely related to the Abortive Infection system (Abi) RTs.
DRT systems were experimentally validated in _Escherichia coli_ and demonstrated to be effective against an array of diverse phages.
So far, DRTs have been classified in 9 different types. Essential components of each DRT type are:
- DRT Type 1: UG1 (RT-nitrilaseTM domains)
- DRT Type 2: UG2 (RT domain)
- DRT Type 3: UG3 (RT domain), UG8 (RT domain) and ncRNA
- DRT Type 4: UG15 (RT-alphaRep domains)
- DRT Type 5: UG16 (RT domain)
- DRT Type 6: UG12 (RT-alphaRep domains)
- DRT Type 7: UG10 (PrimS-RT-alphaRep domains)
- DRT Type 8: UG7 (RT-alphaRep-PDDExK domains)
- DRT Type 9: UG28 (RT-alphaRep domains) and ncRNA
## Molecular mechanism
To our knowledge, the molecular mechanism is unknown.
Similarly, for the other systems of this family, the molecular mechanism remain unknown.
## Example of genomic structure
## Example of genomic structure
A total of 9 subsystems have been described for the DRT system.
A total of 9 subsystems have been described for the DRT system.