Structural change in a B-DNA helix with hydrostatic pressure.

Area of Science:

• Biochemistry
• Structural Biology
• Molecular Biophysics

Background:

• Understanding macromolecular structure under pressure is crucial for comprehending biological systems.
• High pressure can influence molecular forces, hydration, and the function of biological molecules.
• Studying DNA under pressure provides insights into gene activity regulation.

Purpose of the Study:

• To conduct the first high-resolution experimental investigation of B-DNA structure at elevated pressures.
• To elucidate the effects of pressure on DNA conformation and hydrogen bonding.
• To explore the implications of pressure-induced DNA structural changes on hydration.

Main Methods:

• Nuclear Magnetic Resonance (NMR) spectroscopy was employed to acquire data.
• Experiments were performed at pressures up to 200 MPa (2 kbar).
• Analysis focused on changes in DNA structure, groove dimensions, and hydrogen bond compression.

Main Results:

• B-DNA structure exhibits minimal overall compression but significant distortion under high pressure.
• The minor groove of DNA widens, while hydrogen bonds compress, with AT base pairs showing greater compression than GC pairs.
• Pressure-induced widening of the minor groove is correlated with compression of associated hydration water.

Conclusions:

• High pressure induces specific structural alterations in B-DNA, notably minor groove widening and hydrogen bond compression.
• These findings contribute to understanding the biology of high-pressure organisms and the effects of pressure on gene activity.
• The study highlights the intricate relationship between DNA structure, hydration, and environmental pressure.