Assa-Munt N, Kearns D R
Biochemistry. 1984 Feb 28;23(5):791-6. doi: 10.1021/bi00300a001.
The structure of poly(dA-dT) molecules in solution has been probed by using two-dimensional nuclear Overhauser effect spectroscopy. Cross-relaxation patterns arising from internucleotide and intranucleotide interactions are used to assign the sugar proton resonances and to deduce various structural features. The numerous proton-proton interactions that are observed indicate that poly(dA-dT) is a right-handed helix with a B-type conformation. Both the adenine and thymine nucleotides are in an anti conformation. Although slight differences in the purine-sugar and pyrimidine-sugar intranucleotide interactions are observed, the large differences in the sugar pucker of the adenine vs. thymine nucleotide suggested by some models [Klug, A., Jack, A., Viswamitra, M. A., Kennard, O., Shakked, Z., & Steitz, T. A. (1979) J. Mol. Biol. 131, 669-680] are not evident in the solution structure of poly(dA-dT). In the low-temperature spectra there is unexpected evidence for cross-strand AH2-AH2 interactions.
通过使用二维核Overhauser效应光谱对溶液中聚（dA-dT）分子的结构进行了探测。由核苷酸间和核苷酸内相互作用产生的交叉弛豫模式用于确定糖质子共振并推断各种结构特征。观察到的大量质子-质子相互作用表明聚（dA-dT）是具有B型构象的右手螺旋。腺嘌呤和胸腺嘧啶核苷酸均处于反式构象。尽管观察到嘌呤-糖和嘧啶-糖核苷酸内相互作用存在细微差异，但一些模型[Klug, A., Jack, A., Viswamitra, M. A., Kennard, O., Shakked, Z., & Steitz, T. A. (1979) J. Mol. Biol. 131, 669-680]所暗示的腺嘌呤与胸腺嘧啶核苷酸糖环构象的巨大差异在聚（dA-dT）的溶液结构中并不明显。在低温光谱中，存在链间AH2-AH2相互作用的意外证据。
