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Preparation of Viral DNA from Nucleocapsids
Published on: August 16, 2011
Polarized DNA ejection from the herpesvirus capsid.
William W Newcomb1, Shelley K Cockrell, Fred L Homa
1Department of Microbiology and Cancer Center, Box 800734, University of Virginia Health System, 1300 Jefferson Park Avenue, Charlottesville, VA 22908, USA.
Journal of Molecular Biology
|July 28, 2009
Summary
Herpes simplex virus 1 DNA ejection begins at the S segment end, similar to bacteriophages. This preferential release ensures the alpha4 gene is the first transcribed in the host cell nucleus.
Area of Science:
- Virology
- Molecular Biology
Background:
- Herpesviruses initiate infection by ejecting DNA from their capsid into the host cell nucleus.
- This DNA uncoating process is crucial for viral transcription and replication.
Purpose of the Study:
- To determine which end of the herpes simplex virus 1 (HSV-1) genome is ejected first from the capsid.
- To investigate the mechanism of viral DNA uncoating in vitro.
Main Methods:
- Utilized an in vitro uncoating system with purified HSV-1 capsids.
- Bound capsids to a solid surface and induced partial DNA ejection via warming.
- Employed restriction endonuclease digestion to identify the origin of ejected DNA.
Main Results:
- The S segment end of the HSV-1 genome was preferentially ejected first.
- This finding aligns with the packaging mechanism observed in double-stranded DNA bacteriophages.
Conclusions:
- Herpesvirus DNA uncoating follows a specific order, with the S end exiting first.
- Initiation of DNA ejection at the S end leads to the early expression of the alpha4 gene, a key transcription factor for viral gene expression.
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