Related Experiment Video
Updated: Apr 28, 2026
09:08
Generation and Assembly of Virus-Specific Nucleocapsids of the Respiratory Syncytial Virus
Published on: July 27, 2021
3.1K
Characterization of Viral Capsid Protein Self-Assembly around Short Single-Stranded RNA.
Mauricio Comas-Garcia1, Rees F Garmann1, Surendra W Singaram1,2
1Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095, United States.
The Journal of Physical Chemistry. B
|June 17, 2014
Summary
Virus capsid protein (CP) and short RNA interactions drive assembly. Lowering pH facilitates the packaging of four short RNAs into virus-like particles (VLPs), revealing cooperativity in viral genome packaging.
Area of Science:
- Virology
- Biophysics
- Molecular Biology
Background:
- Many viruses spontaneously package single-stranded RNA (ss-RNA) genomes via capsid protein (CP) and RNA interactions.
- Some viruses utilize copackaging of multiple RNA molecules within a single capsid.
Purpose of the Study:
- To investigate in vitro RNA copackaging using cowpea chlorotic mottle virus (CCMV) CP and short RNA molecules (500 nucleotides).
- To determine how RNA length and pH affect the cooperativity of virus assembly.
Main Methods:
- Fluorescence Correlation Spectroscopy (FCS) to analyze CP-RNA complex formation at different pH levels.
- Bulk-solution techniques to characterize the formation of virus-like particles (VLPs).
Main Results:
- Short RNA (500 nt) packaging requires aggregation of multiple CP-RNA complexes, unlike longer wild-type RNAs.
- At neutral pH, smaller CP-RNA complexes form; lowering pH induces packaging of four 500-nt RNAs into VLPs.
- Fully ordered VLPs are formed exclusively upon acidification.
Conclusions:
- The cooperativity of virus assembly is influenced by CP-CP and CP-RNA interactions, as well as RNA length.
- The pH-dependent assembly process suggests an equilibrium between multiple CP/RNA complexes is crucial for high cooperativity in packaging short RNAs.
Related Concept Videos
02:41Protein Complex Assembly
12.5K
Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Many viruses self-assemble into a fully functional unit using the infected host cell to...
12.5K
00:56Viral Structure
58.7K
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.
58.7K
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
01:26Size 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
01:28Introduction to Virus
2.9K
Viruses are unique biological entities that blur the boundary between living and non-living systems. Although they lack cellular structure and metabolic processes, they can exhibit characteristics of life when infecting a host. Their defining feature is a nucleic acid core, composed of either DNA or RNA, encapsulated within a protein coat called a capsid. This simple structure allows them to invade host cells and use their machinery for replication efficiently.Viral Structure and...
2.9K
01:10Retrovirus Life Cycles
42.9K
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...
42.9K