Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Search research articles

Related Experiment Video

Updated: May 15, 2025

Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells

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

Structural basis of antiphage defense by an ATPase-associated reverse transcriptase.

Jerrin Thomas George¹, Nathaniel Burman¹, Royce A Wilkinson¹

¹Montana State University, Bozeman, Department of Microbiology and Cell Biology, Bozeman, Montana 59717, USA.

Biorxiv : the Preprint Server for Biology

|April 8, 2025

Summary

Related Concept Videos

DNA Base Pairing

DNA Base Pairing

Erwin Chargaff’s rules on DNA equivalence paved the way for the discovery of base pairing in DNA. Chargaff’s rules state that in a double-stranded DNA molecule,

Viral Structure

Viral Structure

Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid.

Retrovirus Life Cycles

Retrovirus Life Cycles

Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the...

Lytic Cycle of Bacteriophages

Lytic Cycle of Bacteriophages

Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the...

Retroviruses

Retroviruses

Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...

CRISPR and crRNAs

CRISPR and crRNAs

Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Integrating mass spectrometry with Nanopore direct RNA sequencing for <i>de novo</i> modification profiling of bacteriophage MS2.

bioRxiv : the preprint server for biology·2026

Same author

A census of anti-CRISPR proteins reveals AcrIE9 and AcrIE13 as inhibitors of the <i>Escherichia coli</i> K12 type IE CRISPR-Cas system.

Proceedings of the National Academy of Sciences of the United States of America·2026

Same author

Structural basis of antiphage defence by an ATPase-associated reverse transcriptase.

Nature communications·2025

Same author

Structures reveal how the Cas1-2/3 integrase captures, delivers, and integrates foreign DNA into CRISPR loci.

bioRxiv : the preprint server for biology·2025

Same author

Protein-primed homopolymer synthesis by an antiviral reverse transcriptase.

Nature·2025

Same author

The retrotransposon-derived capsid genes PNMA1 and PNMA4 maintain reproductive capacity.

Nature aging·2025

This study reveals reverse transcriptases (RTs) have dual roles in genetic parasite replication and cellular antiviral defense. Researchers elucidated the structure of a retron complex crucial for phage defense and viral replication arrest.

Area of Science:

Molecular Biology
Structural Biology
Genetics

Background:

Reverse transcriptases (RTs) are primarily known for their roles in retroviral replication.
Emerging evidence indicates RTs also participate in cellular antiviral defense mechanisms.

Purpose of the Study:

To determine the structure of a type I-A retron complex involved in phage defense.
To elucidate the mechanism by which this retron complex mediates antiviral activity.

Main Methods:

X-ray crystallography to determine the 3D structure of the retron complex.
Biochemical assays to analyze the function of the retron complex components.
In vitro assays to study the interaction between retron and phage-encoded factors.

More Related Videos

Nucleocapsid Annealing-Mediated Electrophoresis NAME Assay Allows the Rapid Identification of HIV-1 Nucleocapsid Inhibitors

Nucleocapsid Annealing-Mediated Electrophoresis NAME Assay Allows the Rapid Identification of HIV-1 Nucleocapsid Inhibitors

Published on: January 19, 2015

Engineering Antiviral Agents via Surface Plasmon Resonance

Engineering Antiviral Agents via Surface Plasmon Resonance

Published on: June 14, 2022

Related Experiment Videos

Last Updated: May 15, 2025

Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells

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

Nucleocapsid Annealing-Mediated Electrophoresis NAME Assay Allows the Rapid Identification of HIV-1 Nucleocapsid Inhibitors

Nucleocapsid Annealing-Mediated Electrophoresis NAME Assay Allows the Rapid Identification of HIV-1 Nucleocapsid Inhibitors

Published on: January 19, 2015

Engineering Antiviral Agents via Surface Plasmon Resonance

Engineering Antiviral Agents via Surface Plasmon Resonance

Published on: June 14, 2022

Main Results:

The 364 kDa retron complex comprises RNA, DNA, RT, HNH-nuclease, and SMC-family ATPase.
Phage nucleases trigger retron-associated DNA degradation, leading to complex disassembly.
Activated HNH nuclease cleaves tRNA, halting protein synthesis and viral replication.

Conclusions:

Retrons exhibit paradoxical roles, contributing to both genetic parasite perpetuation and elimination.
The structural and mechanistic insights provide a new understanding of RT functions in host-pathogen interactions.