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Updated: Jun 17, 2025
15:49
Reverse Genetics to Engineer Positive-Sense RNA Virus Variants
Published on: June 9, 2022
1.3K
De novo gene synthesis by an antiviral reverse transcriptase
Stephen Tang1, Valentin Conte1, Dennis J Zhang2
1Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
Science (New York, N.Y.)
|August 8, 2024
Summary
Bacteria possess defense-associated reverse transcriptase (DRT) systems that create new genes from RNA to fight viral infections. DRT2 systems synthesize a unique
Area of Science:
- Bacteriology
- Molecular Biology
- Genetics
Background:
- Defense-associated reverse transcriptase (DRT) systems are known bacterial defense mechanisms against viruses.
- The specific DNA products and functions of DRT systems remain largely uncharacterized.
Purpose of the Study:
- To elucidate the mechanism and function of DRT2 systems in bacterial antiviral defense.
- To investigate the nature of DNA products generated by DRT2 systems.
Main Methods:
- Analysis of DRT2 system components and their interactions.
- Investigating the process of reverse transcription using noncoding RNA (ncRNA) templates.
- Characterization of the synthesized DNA product and its genetic properties.
Main Results:
- DRT2 systems utilize a novel pathway involving rolling circle reverse transcription of ncRNA.
- Programmed template jumping during reverse transcription generates concatemeric cDNA.
- This cDNA is converted to a double-stranded DNA forming a "neo" gene with a near-endless open reading frame.
- Expression of the neo gene induces potent cell growth arrest, restricting viral infection.
Conclusions:
- DRT2 systems represent an unprecedented immune pathway for de novo gene synthesis.
- RNA-templated gene creation expands bacterial genome coding potential.
- This mechanism challenges traditional views of genetic information storage and utilization.
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