Related Experiment Video
Updated: May 5, 2026
09:27
Methodology for the Efficient Generation of Fluorescently Tagged Vaccinia Virus Proteins
Published on: January 17, 2014
10.5K
Vaccinia virus-encoded ribonucleotide reductase subunits are differentially required for replication and pathogenesis
Don B Gammon1, Branawan Gowrishankar, Sophie Duraffour
1Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
Plos Pathogens
|July 15, 2010
Summary
Vaccinia virus (VACV) R2 subunit (F4) is essential for viral replication and virulence, interacting with host R1 subunits. R2-deficient poxviruses show potential as oncolytic agents.
Area of Science:
- Virology
- Molecular Biology
- Biochemistry
Background:
- Ribonucleotide reductases (RRs) are crucial for DNA synthesis, comprising R1 and R2 subunits.
- Poxviruses encode RR subunits; Orthopoxviruses possess both R1 and R2, while Chordopoxviruses typically encode only R2.
Purpose of the Study:
- Investigate the roles of vaccinia virus (VACV) R1 (I4) and R2 (F4) subunits in viral replication and pathogenesis.
- Determine the functional interaction between viral and host RR subunits.
Main Methods:
- Generation and analysis of VACV mutant strains lacking I4 and/or F4.
- Plaque morphology, growth curves, and mouse virulence studies.
- Co-immunoprecipitation to assess protein interactions.
Main Results:
- VACV F4, not I4, is essential for efficient viral replication and mouse virulence.
- VACV F4 interacts with host R1 subunits, forming functional complexes critical for replication.
- R2-deficient poxviruses may serve as selective oncolytic agents.
Conclusions:
- Poxvirus R2 subunits rely on host R1 subunits for efficient viral replication.
- The interaction between viral R2 and host R1 is vital for poxvirus dNTP supply.
- Poxvirus nucleotide metabolism offers insights into pathogen evolution and potential therapeutic applications.
Related Concept Videos
01:10Retrovirus Life Cycles
43.0K
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...
43.0K
00:36Viral Mutations
33.0K
A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material...
33.0K
02:28Leaky Scanning
4.5K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...
4.5K
01:26Size and Structure of Viral Genomes
1.2K
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...
1.2K
01:29Viruses with RNA Genomes
1.5K
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
1.5K
01:29Subviral Agents
933
Subviral agents are infectious entities that resemble viruses but lack one or more viral components, such as a capsid or essential replication machinery. These agents include viroids, prions, and satellites, each possessing distinct structural and functional characteristics that influence their mode of infection and replication.Viroids are the simplest subviral agents, consisting of circular, single-stranded RNA molecules without a protein coat. They exclusively infect plants, relying entirely...
933