Evans F E, Sarma R H
Nature. 1976 Oct 14;263(5578):567-72. doi: 10.1038/263567a0.
It is show that in aqueous solution the backbone conformation of adenosine is as much flexible as that of 3'-AMP, 5'-AMP and 3', 5'-ADP indicating that nucleotides are not any more rigid than nucleosides. The flexible conformation of the monomeric components is conserved in the nucleotidyl units of destacked ApA, ApApA and poly(A), but it is not conserved in base stacked conditions. The findings are extended to guanosine, uridine and cytidine systems. It is projected that in aqueous solution, conformations of the individual nucleotidyl units of yeast tRNAhe are confined to the classically stable domains in the base stacked region and non-rigid flexible structures populate in the unstacked region comprising D16, D17, G20, U47 and A76.
结果表明，在水溶液中，腺苷的主链构象与3'-AMP、5'-AMP和3',5'-ADP一样具有柔性，这表明核苷酸并不比核苷更刚性。单体组分的柔性构象在解堆叠的ApA、ApApA和聚（A）的核苷酸单元中得以保留，但在碱基堆叠条件下则不被保留。这些发现扩展到了鸟苷、尿苷和胞苷系统。据推测，在水溶液中，酵母tRNAhe的各个核苷酸单元的构象在碱基堆叠区域局限于经典稳定结构域，而在包括D16、D17、G20、U47和A76的未堆叠区域中则存在非刚性的柔性结构。
