The mechanism of B-A transition in DNA molecule: Elastic interactions between sugars and nitrous bases

A two-component model with elastic interactions between subsystems was proposed, which describes conformational transitions in the DNA molecule. The model is applicable for the description of B-->A transitions in the DNA molecule. It is shown that conformational excitations propagate along the macromolecule via stable topological solitons having a definite velocity. Two types of solitons can be distinguished: exciting and reducing. The exciting soliton realizes the transition of sugar from the ground state to a metastable state; in this process, the distance between complementary bases increases. The reducing soliton is formed behind the exciting soliton and realizes a reverse transition.