Structure of triplex DNA in the gas phase

Area of Science:

• Biochemistry
• Structural Biology
• Physical Chemistry

Background:

• DNA structures, like triplexes, are typically stabilized by solvent interactions.
• Understanding DNA structure in the absence of solvent is crucial for fundamental knowledge.

Purpose of the Study:

• To characterize the gas-phase conformational ensemble of DNA triplexes.
• To investigate the structural memory and stability of DNA triplexes in isolation.

Main Methods:

• Extensive molecular dynamics simulations (over 90 microseconds).
• Ion-mobility mass spectrometry experiments.

Main Results:

• Gas-phase DNA triplexes exhibit a well-defined conformational ensemble.
• Structures retain significant native contacts and helicity, mimicking solution structures.
• Structural alterations are significant but comparable to duplexes, not G-quadruplexes.

Conclusions:

• DNA triplexes retain 3D structure and native contacts in the gas phase, defying expectations.
• Solvent screening, hydrophobic effects, and solvation are not solely responsible for DNA structure stability.
• DNA's inherent properties allow for remarkable structural preservation without solvent.