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Active DNA unwinding dynamics during processive DNA replication.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2012 May 22; Vol. 109 (21), pp. 8115-20. Date of Electronic Publication: 2012 May 09. - Publication Year :
- 2012
-
Abstract
- Duplication of double-stranded DNA (dsDNA) requires a fine-tuned coordination between the DNA replication and unwinding reactions. Using optical tweezers, we probed the coupling dynamics between these two activities when they are simultaneously carried out by individual Phi29 DNA polymerase molecules replicating a dsDNA hairpin. We used the wild-type and an unwinding deficient polymerase variant and found that mechanical tension applied on the DNA and the DNA sequence modulate in different ways the replication, unwinding rates, and pause kinetics of each polymerase. However, incorporation of pause kinetics in a model to quantify the unwinding reaction reveals that both polymerases destabilize the fork with the same active mechanism and offers insights into the topological strategies that could be used by the Phi29 DNA polymerase and other DNA replication systems to couple unwinding and replication reactions.
- Subjects :
- DNA Helicases metabolism
DNA, Viral chemistry
DNA-Directed DNA Polymerase metabolism
Gene Expression Regulation, Viral physiology
Molecular Motor Proteins physiology
Nucleic Acid Conformation
Stress, Mechanical
Viral Proteins genetics
Viral Proteins metabolism
Bacillus Phages genetics
DNA Helicases genetics
DNA Replication genetics
DNA, Viral genetics
DNA-Directed DNA Polymerase genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1091-6490
- Volume :
- 109
- Issue :
- 21
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 22573817
- Full Text :
- https://doi.org/10.1073/pnas.1204759109