Genome chromatinization in giant double-stranded DNA viruses
1Institut Pasteur, Université de Paris, Archaeal Virology Unit, F-75015 Paris, France.
Trends in Biochemical Sciences
|October 18, 2021
Summary
Giant viruses possess large DNA genomes and complex structures. Recent studies reveal they encode unique histone doublets, forming nucleosomes similar to those in eukaryotes.
Area of Science:
- Virology
- Molecular Biology
- Genetics
Background:
- Giant viruses are characterized by exceptionally large double-stranded DNA genomes.
- Their virions exhibit complex structures, reflecting unique biological adaptations.
Purpose of the Study:
- To investigate the packaging of giant viral genomes.
- To identify and characterize proteins involved in viral DNA organization within giant viruses.
Main Methods:
- Comparative genomics to identify unique viral genes.
- Structural biology techniques to analyze protein complexes.
- Biochemical assays to study DNA-protein interactions.
Main Results:
- Discovery of unique histone doublets encoded by some giant viruses.
- Demonstration that these histone doublets assemble into nucleosome-like structures.
- Structural and functional similarities between viral nucleosomes and eukaryotic nucleosomes.
Conclusions:
- Giant viruses utilize nucleosome-like structures for DNA packaging, a feature previously thought to be exclusive to eukaryotes.
- This finding challenges our understanding of viral genome organization and evolution.
- Suggests a potential link or convergent evolution between giant viruses and eukaryotic chromatin.
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