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In vitro increases in plasmid DNA supercoiling by hydrostatic pressure
1Laboratory for Biopolymer Physics, Department of Polymer Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo, Kyoto 606-8585, Japan.
Biochimica Et Biophysica Acta
|January 8, 1999
Summary
Elevated pressure increases DNA supercoiling, winding the DNA duplex more tightly. This study is the first to investigate pressure effects on DNA supercoiling using topoisomerase assays.
Area of Science:
- Biochemistry
- Molecular Biology
- Biophysics
Background:
- DNA supercoiling is crucial for DNA replication and transcription.
- Topoisomerase I enzymes regulate DNA supercoiling.
- The impact of hydrostatic pressure on DNA tertiary structure is not well understood.
Purpose of the Study:
- To investigate the effects of elevated hydrostatic pressure on DNA supercoiling.
- To quantify the pressure-induced changes in DNA linking numbers.
- To explore the implications of pressure-induced DNA structural changes.
Main Methods:
- Topoisomerase I-mediated supercoiling assays were performed.
- Plasmid DNA was subjected to varying hydrostatic pressures.
- Changes in DNA linking numbers were measured.
Main Results:
- Elevated pressure caused a progressive increase in plasmid DNA linking numbers.
- DNA duplex winding increased by 1.1-1.6x10^-3 angular degrees/base/MPa with pressure elevation.
- These findings suggest pressure disturbs the tertiary structure of DNA.
Conclusions:
- Hydrostatic pressure directly influences DNA supercoiling.
- Pressure-induced alterations in DNA tertiary structure have significant biological implications.
- Further research is needed to fully elucidate the mechanisms and consequences of pressure effects on DNA.