Superstructural information in DNA sequences: from structural toward functional genomics.

Although DNA is iconized as a straight double helix, it does not exist in this canonical form in biological systems. Instead, it is characterized by sequence dependent structural and dynamic deviations from the monotonous regularity of the canonical B-DNA. Despite the complexity of the system, we showed that DNA structural and dynamics large-scale properties can be predicted starting from the simple knowledge of nucleotide sequence by adopting a statistical approach. The paper reports the statistical analysis of large pools of different prokaryotic genes in terms of the sequence-dependent curvature and flexibility. Conserved features characterize the regions close to the Start Translation Site, which are related to their function in the regulation system. In addition, regular patterns with three-fold periodicity were found in the coding regions. They were reproduced in terms of the nucleotide frequency expected on the basis of the genetic code and the pertinent occurrence of the aminoacid residues.