Day R O, Seeman N C, Rosenberg J M, Rich A
Proc Natl Acad Sci U S A. 1973 Mar;70(3):849-53. doi: 10.1073/pnas.70.3.849.
The sodium salt of guanylyl-3',5'-cytidine crystallizes in a monoclinic unit cell with one molecule in the asymmetric unit. Each molecule is related to another molecule by a 2-fold rotation axis which results in the formation of an antiparallel, right-handed double helix with complementary hydrogen bonding between the guanine and cytosine residues. The crystal is heavily hydrated with 36 water molecules in the unit cell. The geometry of this crystalline double helix is very similar to those which have been derived from studies of fiber x-ray diffraction patterns of double-stranded RNA, even though the latter do not yield data at atomic resolution.
鸟苷-3',5'-胞苷钠盐在单斜晶胞中结晶,不对称单元中有一个分子。每个分子通过一个二次旋转轴与另一个分子相关,这导致形成一个反平行的右手双螺旋,鸟嘌呤和胞嘧啶残基之间存在互补氢键。该晶体在晶胞中含有36个水分子,严重水合。这种结晶双螺旋的几何结构与那些通过双链RNA纤维X射线衍射图研究得出的结构非常相似,尽管后者无法提供原子分辨率的数据。