DNA structure plays an important role in a variety of biological processes. Different di- and tri-nucleotide scales have been proposed to capture various aspects of DNA structure including base stacking energy, propeller twist angle, protein deformability, bendability, and position preference. Yet, a general framework for the computational analysis and prediction of DNA structure is still lacking. Such a framework should in particular address the following issues: (1) construction of sequences with extremal properties, (2) quantitative evaluation of sequences with respect to a given genomic background, (3) automatic extraction of extremal sequences and profiles from genomic databases, (4) distribution and asymptotic behavior as the length N of the sequences increases, and (5) complete analysis of correlations between scales.