New Molecular Systems. Regularities of Supramolecular Biopolymer Structure Formation

A new model of supramolecular structure of DNA is proposed, according to which the processes caused by the monomer rearrangements in the carcass of the molecule underlie DNA compactization. Rearrangement in the DNA chain can result in the appearance of dimers of three types with different bending angles. The dimer geometry corresponds to geometrical figures (correct tetrahedron and octahedron) conforming to the volume-surface economy rule. These figures serve as the unit of a correct crystal lattice. The formation of a DNA supramolecular unit (nucleosome) is realized in accordance with the “golden ratio” rule. The minimum fragment used in assembly of the nucleosome core consists of two mini-segments: large (containing 8 monomers) and small (5 monomers). This model suggests the conformations of functional proteins, that is, the DNA matrix determines the amino acid sequence in the protein polymer chain.