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Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells
Published on: January 30, 2019
A bacterial reverse transcriptase: Protein-templated DNA synthesis fuels antiviral immunity
Yumin Yang1, Mingxing Zhang1, Hui Yang1
1Key Laboratory of RNA Science and Engineering, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China.
Molecular Cell
|July 2, 2026
Summary
Researchers discovered a bacterial enzyme, DRT3, that creates double-stranded DNA from RNA templates. This enzyme plays a role in antiviral immunity by expanding the functions of reverse transcriptases.
Area of Science:
- Molecular Biology
- Biochemistry
- Immunology
Background:
- Reverse transcriptases (RTs) are enzymes known for synthesizing DNA from RNA templates, primarily studied in retroviruses and eukaryotes.
- Bacterial defense mechanisms are diverse and constantly evolving to combat foreign genetic elements like viruses.
- The functional diversity of RTs in prokaryotes, particularly in defense pathways, remains an area of active investigation.
Purpose of the Study:
- To identify and characterize novel reverse transcriptase activities in bacterial defense systems.
- To elucidate the mechanism by which a bacterial RT synthesizes double-stranded DNA.
- To explore the role of this enzyme in bacterial antiviral immunity.
Main Methods:
- Bioinformatic analysis to identify potential RT candidates in bacterial genomes.
- Biochemical assays to test the enzymatic activity of the identified protein (DRT3).
- In vitro synthesis experiments using various RNA and DNA templates to determine substrate specificity and product formation.
- Structural and mechanistic studies to understand the coupling of RNA-templated and protein-templated synthesis.
Main Results:
- Identification and characterization of a novel bacterial reverse transcriptase, designated DRT3.
- DRT3 synthesizes poly(GT/AC) repeat double-stranded DNA.
- The synthesis mechanism involves a unique coupling of RNA-templated and protein-templated processes.
- DRT3 exhibits activity against viral genetic material, suggesting a role in antiviral defense.
Conclusions:
- DRT3 represents a novel class of bacterial defense-associated reverse transcriptases.
- The enzyme's unique DNA synthesis mechanism expands the known functions of RTs.
- DRT3 contributes to bacterial antiviral immunity, highlighting a new layer of prokaryotic defense strategies.
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