Chastain M, Tinoco I
University of California, Berkeley 94720.
Prog Nucleic Acid Res Mol Biol. 1991;41:131-77. doi: 10.1016/s0079-6603(08)60008-2.
This chapter describes the RNA structural characteristics that have emerged so far. Folded RNA molecules are stabilized by a variety of interactions, the most prevalent of which are stacking and hydrogen bonding between bases. Many interactions among backbone atoms also occur in the structure of tRNA, although they are often ignored when considering RNA structure because they are not as well-characterized as interactions among bases. Backbone interactions include hydrogen bonding and the stacking of sugar or phosphate groups with bases or with other sugar and phosphate groups. The interactions found in a three-dimensional RNA structure can be divided into two categories: secondary interactions and tertiary interactions. This division is useful for several reasons. Secondary structures are routinely determined by a combination of techniques discussed in chapter whereas tertiary interactions are more difficult to determine. Computer algorithms that generate RNA structures can search completely through possible secondary structures, but the inclusion of tertiary interactions makes a complete search of possible structures impractical for RNA molecules even as small as tRNA. The division of RNA structure into building blocks consisting of secondary or tertiary interactions makes it easier to describe RNA structures. In those cases in which RNA studies are incomplete, the studies of DNA are described with the rationalization that RNA structures may be analogous to DNA structures, or that the techniques used to study DNA could be applied to the analogous RNA structures. The chapter focuses on the aspects of RNA structure that affect the three-dimensional shape of RNA and that affect its ability to interact with other molecules.
本章描述了迄今为止所发现的RNA结构特征。折叠的RNA分子通过多种相互作用得以稳定，其中最普遍的是碱基之间的堆积和氢键作用。在tRNA结构中，主链原子之间也存在许多相互作用，不过在考虑RNA结构时，这些相互作用常常被忽略，因为它们不像碱基之间的相互作用那样得到充分表征。主链相互作用包括氢键作用以及糖基或磷酸基团与碱基之间或与其他糖基和磷酸基团之间的堆积作用。在三维RNA结构中发现的相互作用可分为两类：二级相互作用和三级相互作用。这种划分有几个方面的用处。二级结构通常通过第二章中讨论的多种技术组合来确定，而三级相互作用则更难确定。生成RNA结构的计算机算法可以全面搜索可能的二级结构，但即使对于像tRNA这么小的RNA分子，纳入三级相互作用后要全面搜索可能的结构也不切实际。将RNA结构划分为由二级或三级相互作用组成的构建模块，使得描述RNA结构更加容易。在那些RNA研究尚不完整的情况下，会借助这样的理由来描述DNA研究，即RNA结构可能类似于DNA结构，或者用于研究DNA的技术可以应用于类似的RNA结构。本章重点关注影响RNA三维形状以及影响其与其他分子相互作用能力的RNA结构方面。
