[Mechanism of the radiation damage to the secondary structure of DNA].

The authors describe the mechanism of radiation-induced damage of a secondary DNA structure suggesting that a double-helical brim conformation adjacent to a local defect in the secondary structure, and the thermoactivated threshold process of a "confluence" of the defects are present in the irradiated DNA. It is supposed that the major type of the radiation damage to the spatial DNA structure is a triple helix repaired with the aid of the specific endonuclease.