Origin-specific unwinding of herpes simplex virus 1 DNA by the viral UL9 and ICP8 proteins: Visualization of a specific preunwinding complex
AUTOR(ES)
Makhov, Alexander M.
FONTE
The National Academy of Sciences
RESUMO
Herpes simplex virus 1 contains three origins of replication; two copies of oriS and one of a similar sequence, oriL. Here, the combined action of multiple factors known or thought to influence the opening of oriS are examined. These include the viral origin-binding protein, UL9, and single-strand binding protein ICP8, host cell topoisomerase I, and superhelicity of the DNA template. By using electron microscopy, it was observed that when ICP8 and UL9 proteins were added together to oriS-containing supertwisted DNA, a discrete preunwinding complex was formed at oriS on 40% of the molecules, which was shown by double immunolabeling electron microscopy to contain both proteins. This complex was relatively stable to extreme dilution. Addition of ATP led to the efficient unwinding of ≈50% of the DNA templates. Unwinding proceeded until the acquisition of a high level of positive supertwists in the remaining duplex DNA inhibited further unwinding. Addition of topoisomerase I allowed further unwinding, opening >1 kb of DNA around oriS.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=298698Documentos Relacionados
- Binding of the herpes simplex virus type 1 UL9 gene product to an origin of viral DNA replication.
- Functional Interaction between the Herpes Simplex Virus Type 1 Polymerase Processivity Factor and Origin-Binding Proteins: Enhancement of UL9 Helicase Activity
- Herpes simplex virus DNA replication: the UL9 gene encodes an origin-binding protein.
- Herpes simplex virus type 1 origin-specific binding protein: oriS-binding properties and effects of cellular proteins.
- Nucleoprotein complex formed between herpes simplex virus UL9 protein and the origin of DNA replication: inter- and intramolecular interactions.
