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Presence of protein at the termini of intracellular adenovirus type 5 DNA
Abstract:
Adenovirus type 5 contains linear double-stranded DNA with protein covalently attached to the ends of the molecules. The presence of protein at the termini of intracellular viral DNA in adenovirus type 5-infected cells was investigated at different stages during the replication process. The intracellular viral DNA was isolated from the nuclei by lysis in 4 M guanidine hydrochloride. Electrophoresis on agarose gels of HsuI restriction enzyme fragments and sucrose gradient centrifugation were used to detect protein on intracellular viral DNA. After uncoating parental DNA still contains protein attached to the termini of the viral genome. Replicating and mature progeny viral DNA can also be isolated in the form of DNA-protein complexes. These complexes exhibit the same properties as the DNA-protein complex isolated from purified virions. These results suggest that the protein at the termini of intracellular viral DNA is identical to the protein attached to the 5'-ends of the DNA extracted from virions and that it is possibly involved in the replication of viral DNA.
Insights
Adenovirus type 5 DNA retains terminal protein throughout replication. This protein, found on parental, replicating, and progeny viral DNA, is likely crucial for viral DNA replication.
Area of Science:
- Molecular Biology
- Virology
- Genetics
Background:
- Adenovirus type 5 possesses linear double-stranded DNA genomes.
- This DNA has covalently attached proteins at its molecular ends.
Purpose of the Study:
- To investigate the presence and nature of terminal proteins on intracellular adenovirus type 5 DNA.
- To determine if this protein persists during viral DNA replication.
Main Methods:
- Isolation of intracellular viral DNA from infected cell nuclei using 4 M guanidine hydrochloride.
- Analysis via agarose gel electrophoresis of HsuI restriction fragments.
- Detection of DNA-protein complexes using sucrose gradient centrifugation.
Main Results:
- Parental adenovirus DNA retains terminal proteins after uncoating.
- Replicating and progeny viral DNA exist as DNA-protein complexes.
- These complexes share properties with virion DNA-protein complexes.
Conclusions:
- The terminal protein on intracellular viral DNA is identical to that found in virions.
- This terminal protein is likely involved in the replication of adenovirus type 5 DNA.