title: A model for the single stranded random coil form of polydeoxyadenylic acid from minimum energy conformations of the dimeric subunit.
abstract: The minimum energy conformations of dApdA have been examined for their suitability as buildings blocks of the single stranded coil form of polynucleotides. Calculations of the characteristic ratio C difference = less than ro greater than 2/n liter2 were made for a polymer generated from all the low energy conformers, as well as for selected combinations. A polymer composed of a conformer with omega', omega = t*,g+,(skewed) psi = t, C-(2)-endo type pucker, in combination with the 'B' form, has a C difference equal to that observed in coils of apurinic acid (6) when the fraction of 'B' form conformers is approximately 25% and approximately 91%. The t*,g+ conformer is the second lowest energy form in the C-(2)-endo puckering domain, following the 'B' form.
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D008954:Models, Biological; D009690:Nucleic Acid Conformation; D011061:Poly A; D011089:Polydeoxyribonucleotides; D013696:Temperature; D013816:Thermodynamics
chemical_list: D011089:Polydeoxyribonucleotides; D011061:Poly A