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Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses
Published on: December 29, 2015
To build a virus on a nucleic acid substrate.
Adam Zlotnick1, J Zachary Porterfield, Joseph Che-Yen Wang
1Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA. azlotnic@indiana.edu
Biophysical Journal
|April 9, 2013
Summary
Viral capsid assembly is governed by capsid protein (CP) and nucleic acid (NA) interactions. A new phase diagram predicts viral assembly success or failure based on these interactions and NA packaging work.
Area of Science:
- Virology
- Biophysics
- Structural Biology
Background:
- Viruses assemble by packaging their genetic material within a protein shell (capsid).
- Understanding the physical principles governing viral capsid assembly is crucial for virology and antiviral drug development.
- Previous models often simplified the complex interactions between viral proteins and nucleic acids during assembly.
Purpose of the Study:
- To develop a quantitative framework describing viral genome packaging and capsid assembly.
- To identify key parameters influencing the success or failure of viral assembly.
- To predict viral assembly outcomes based on biophysical properties.
Main Methods:
- Development of a theoretical model incorporating three key coefficients: CP-NA association (KNA), CP-CP interaction (ω), and work to package NA (α).
- Construction of a phase diagram plotting lnα versus lnω to delineate assembly regimes.
- Comparison of the model's predictions with experimental data from Cowpea Chlorotic Mottle Virus, Hepatitis B Virus, and Simian Virus 40.
Main Results:
- Viral assembly can be characterized by the interplay between CP-NA association, CP-CP interactions, and the energetic cost of NA packaging.
- The phase diagram reveals distinct regions for successful assembly, failure, and aberrant particle formation.
- Nucleic acid (NA) morphology significantly impacts assembly, with favorable (lnα > 0) or impeding (lnα < 0) effects.
- Increased CP-CP interaction (larger lnω) enhances capsid stability and cooperativity.
Conclusions:
- The developed theoretical formalism provides a robust method for describing and predicting viral capsid assembly.
- The model accurately explains experimental observations for diverse viruses and nucleic acid types.
- This framework can guide future experimental studies and therapeutic strategies targeting viral assembly.
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