Bachelin M, Hessler G, Kurz G, Hacia J G, Dervan P B, Kessler H
Institut für Organische Chemie und Biochemie, TU München, Garching, Germany.
Nat Struct Biol. 1998 Apr;5(4):271-6. doi: 10.1038/nsb0498-271.
In this work, we present the first NMR solution structure of a DNA/RNA hybrid containing stereoregular Rp-phosphorothioate modifications of all DNA backbone linkages. The complex of the enzymatically synthesized phosphorothioate DNA octamer (all-Rp)-d(GCGTCAGG) and its complementary RNA r(CCUGACGC) was found to adopt an overall conformation within the A-form family. Most helical parameters and the sugar puckers of the DNA strand assume values intermediate between A- and B-form. The close structural similarity with the unmodified DNA/RNA hybrid of the same sequence may explain why both the natural and the sulfur-substituted complex can be recognized and digested by ribonuclease H.
在本研究中，我们展示了首个包含所有DNA主链连接均为立体规整Rp-硫代磷酸酯修饰的DNA/RNA杂交体的核磁共振溶液结构。酶促合成的硫代磷酸酯DNA八聚体（全Rp）-d(GCGTCAGG)与其互补RNA r(CCUGACGC)的复合物被发现整体构象属于A型家族。DNA链的大多数螺旋参数和糖环构象取值介于A 型和B型之间。与相同序列的未修饰DNA/RNA杂交体在结构上的高度相似性或许可以解释为何天然复合物和硫取代复合物都能被核糖核酸酶H识别并消化。
