Olson W K
Proc Natl Acad Sci U S A. 1977 May;74(5):1775-9. doi: 10.1073/pnas.74.5.1775.
Structural details are reported for a novel right-handed polynucleotide double helix stabilized by vertical base stacking and hydrogen bonding. The primary difference between this duplex and the familiar Watson-Crick horizontally stabilized polynucleotide complex arises in the glycosyl rotation of the heterocyclic bases with respect to the sugar-phate backbone. In the vertical double helix the bases adopt a fairly unusual (although not sterically impossible) high-anti conformation, while in the horizontal models deduced from x-ray analyses the bases occur in the favored anti arrangement. The base pairing scheme in both duplexes is the standard Watson-Crick type. The vertical double helix is demonstrated to be a plausible model for the unusual complex formation observed between complementary synthetic polycyclonucleotides (the bases of which are fixed by a chemical linkage in the high-anti orientation) and also a potential alternative ordered structure available to naturally occurring nucleic acid systems that can adopt both anti and high-anti glycosyl arrangements.
报道了一种通过垂直碱基堆积和氢键稳定的新型右手多核苷酸双螺旋的结构细节。这种双链体与常见的沃森-克里克水平稳定多核苷酸复合物之间的主要差异在于杂环碱基相对于糖-磷酸骨架的糖基旋转。在垂直双螺旋中，碱基采取一种相当不寻常的（尽管在空间上并非不可能）高反式构象，而在从X射线分析推导的水平模型中，碱基以有利的反式排列出现。两种双链体中的碱基配对方案均为标准的沃森-克里克类型。垂直双螺旋被证明是互补合成多环核苷酸之间观察到的异常复合物形成的一个合理模型（其碱基通过化学连接固定在高反式取向），也是天然存在的核酸系统可采用的一种潜在的替代有序结构，这些核酸系统可以采用反式和高反式糖基排列。
