Broyde S, Hingerty B
Nucleic Acids Res. 1979;6(6):2165-78. doi: 10.1093/nar/6.6.2165.
Addition of 3' and 5' terminal phosphates to dApdA causes a decrease in conformational flexibility. pdApdAp has much fewer conformers with energies below 2.5 kcal./mole than dApdA. THE A, B and Watson-Crick (34) helices are the most preferred forms. Other important conformations are in the trans domain of psi. Thus, flexibility in psi as well as in omega and omega, and in the sugar pucker is indicated. The transformation from the B helix to the Watson-Crick helix follows a low energy path. This is significant since Watson-Crick conformations may be important for intercalation into nucleic acid polymers (40-42) above the dimer level. The B helix is preferred over the A form in these large DNA subunits.
在dApdA上添加3'和5'末端磷酸会导致构象灵活性降低。与dApdA相比,pdApdAp具有能量低于2.5千卡/摩尔的构象异构体要少得多。A、B和沃森-克里克(34)螺旋是最优选的形式。其他重要构象存在于ψ的反式结构域中。因此,表明了ψ以及ω和ω'以及糖环构象的灵活性。从B螺旋向沃森-克里克螺旋的转变遵循低能量路径。这很重要,因为沃森-克里克构象对于在二聚体水平以上插入核酸聚合物(40 - 42)可能很重要。在这些大的DNA亚基中,B螺旋比A形式更受青睐。