STABILITY AND PROPERTIES OF DOUBLE AND TRIPLE HELICES - DRAMATIC EFFECTS OF RNA OR DNA BACKBONE COMPOSITION
STABILITY AND PROPERTIES OF DOUBLE AND TRIPLE HELICES - DRAMATIC EFFECTS OF RNA OR DNA BACKBONE COMPOSITION
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DOI：
10.1126/science.1279808
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发表时间：
1992-11-27
期刊：
影响因子：
56.9
通讯作者：
CROTHERS, DM
中科院分区：
文献类型：
--
作者：
ROBERTS, RW;CROTHERS, DM
对一系列含有全部RNA、全部DNA或两者混合物的短寡核苷酸双螺旋和三螺旋的研究表明，它们的稳定性和结构存在链依赖性变化。两组福尔斯的稳定性变化都落在大于10千卡/摩尔的范围内。在形成三螺旋时，RNA在两条嘧啶链上都是有利的，而DNA在嘌呤链上是有利的。通常，相对不稳定的双链体形成特别稳定的三链体，反之亦然。结构数据表明，混合螺旋中的链采用了一种介于含有所有DNA和所有RNA的分子之间的构象。因此，RNA-DNA杂交体不会被迫进入RNA的构象（A型）。具有RNA第三链+ DNA双链体的三链体的挑衅性稳定性指向新的反义策略，并打开了这些结构在体内作用的可能性。总的来说，这些数据强调了糖在决定核酸复合物性质方面的基本作用。
Studies of a series of short oligonucleotide double and triple helices containing either all RNA, all DNA, or a mixture of the two show strand-dependent variation in their stability and structure. The variation in stability for both groups falls over a range of greater than 10 kilocalories per mole. In forming the triple helix, RNA is favored on both pyrimidine strands, whereas DNA is favored on the purine strand. In general, relatively unstable duplexes form particularly stable triplexes and vice versa. Structural data indicate that the strands in hybrid helices adopt a conformation that is intermediate between molecules containing all DNA and all RNA. Thus, RNA-DNA hybrids were not forced into the conformation of the RNA (A-form). The provocative stability of the triplex with an RNA third strand + DNA duplex points to novel antisense strategies and opens the possibility of an in vivo role of these structures. Overall, the data emphasize the fundamental role of sugars in determining the properties of nucleic acid complexes.