DNA damage induces long range changes to duplex structure-a non-protein start to damage detection?

DNA damage causes long-range structural and dynamic changes in duplex DNA, with modifications like abasic sites and nicks significantly altering FRET signals across the molecule.

• Why it matters: Understanding how proteins detect DNA damage is crucial for insights into repair mechanisms, yet the physical signals that distinguish damaged from undamaged DNA remain poorly understood due to DNA's dynamic nature.
• What they did: Using confocal single-molecule FRET, researchers analyzed nine dye pairs across five DNA duplexes with various modifications involved in base excision repair, measuring changes in bending, twisting, and stretching.
• The result: All damage types altered FRET efficiencies, especially at sites like abasic sites and nicks, indicating that structural flexibility changes could serve as early signals for repair protein recruitment.