Summary
A Nature study describes DRT10, a bacterial antiviral system that uses a noncoding RNA to guide repeat-DNA synthesis. Its RNA-templated mechanism has parallels with eukaryotic telomerase.
A peer-reviewed study published in Nature on 12 October 2026 describes DRT10, a bacterial antiviral defense system that uses a noncoding RNA (ncRNA) to guide the production of tandem-repeat DNA. The researchers combined cryo-electron microscopy, biochemical experiments and phylogenetic analysis to investigate how the system works.
The mechanism resembles one used by eukaryotic telomerase: both involve an RNA template directing the addition of repeated DNA. DRT10, however, is described as part of bacterial antiviral immunity, not as a telomerase enzyme performing telomere maintenance.
How DRT10 makes repeat DNA
DRT10 belongs to a group called defense-associated reverse transcriptases, or DRTs. Reverse transcriptases make DNA from an RNA template. In DRT10, the template is part of an ncRNA, and the researchers found that a particular sequence pattern and boundary elements in that RNA are essential for adding DNA repeats.
Cryo-EM reconstructions revealed two reverse-transcriptase protein units bound to opposite sides of a roughly symmetrical ncRNA. Biochemical experiments showed that each unit can copy the template on its side of the RNA, but only one produces the long repetitive DNA product. The region copied repeatedly is defined by the spacing between two stem-loop structures in the RNA. This arrangement lets the enzyme add successive DNA repeats within boundaries set by the RNA.
A shared logic with telomerase
Telomerase extends the ends of eukaryotic chromosomes by using RNA to guide the addition of DNA repeats. DRT10’s repeat addition has a similar basic logic, although the reported biological role is different: bacterial antiviral defense. The study adds another example of bacteria using reverse transcription as part of their defenses against viruses.
The researchers also compared reverse transcriptases across domains of life. Their phylogenetic analyses place telomerase in a monophyletic group with the DRT family, which the authors say suggests a common origin for their DNA-polymerization activities. That is an evolutionary interpretation of the sequence relationships, alongside the study’s structural and biochemical findings.
The article is an early-access version of accepted research. Nature says it may receive further edits before publication of the final Version of Record.