The smaller helical repeat of poly(dA) . poly(dT) relative to DNA may reflect the wedge property of the dA . dT base pair.
A simple geometric approach is described which suggests that the smaller helical repeat of the homopolymer poly(dA) . poly(dT) relative to DNA (10.1 against 10.6 base pairs/turn) quantitatively reflects the property of the dA . dT base pair to behave like a wedge, of angle 11 degrees, pointing towards dA.
D001482:Base Composition; D001483:Base Sequence; D055598:Chemical Phenomena; D002621:Chemistry; D004247:DNA; D008433:Mathematics; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D011067:Poly dA-dT; D011089:Polydeoxyribonucleotides; D012091:Repetitive Sequences, Nucleic Acid
D011089:Polydeoxyribonucleotides; D011067:Poly dA-dT; D004247:DNA