  The approach for the description of the DNA conformational transformations on
the mesoscopic scales in the frame of the double helix is presented. Due to
consideration of the joint motions of DNA structural elements along the
conformational pathways the models for different transformations may be
constructed in the unifying two-component form. One component of the model is
the degree of freedom of the elastic rod and another component -- the effective
coordinate of the conformational transformation. The internal and external
model components are interrelated, as it is characteristic for the DNA
structure organization. It is shown that the kinetic energy of the
conformational transformation of heterogeneous DNA may be put in homogeneous
form. In the frame of the developed approach the static excitations of the DNA
structure under the transitions between the stable states are found for
internal and external components. The comparison of the data obtained with the
experiment on intrinsic DNA deformability shows good qualitative agreement. The
conclusion is made that the found excitations in the DNA structure may be
classificated as the static conformational solitons.
