Robaglia C, Bruening G, Haseloff J, Gerlach W L
Laboratoire de Biologie Cellulaire, Versailles, France.
EMBO J. 1993 Jul;12(7):2969-76. doi: 10.1002/j.1460-2075.1993.tb05959.x.
The replication properties of linker insertion-deletion mutants of tobacco ringspot virus satellite RNA have been studied by amplification in plants infected with the helper virus. Sequence analysis of the cDNAs corresponding to the replicated forms shows that only one of the original mutated molecules replicates unaltered, and in general new variants accumulate. Depending on the location of the original mutation three types of sequence modifications were observed: (i) deletion of the mutated region followed by sequence duplication, (ii) sequence duplication and deletion outside of the mutated region and (iii) limited rearrangements at the site of mutation. The mutant that replicates without sequence changes accumulates linear multimeric forms suggesting that self-cleavage is affected although the sequence alteration does not involve the hammerhead catalytic domain. Alternative RNA conformations are likely to play a role in the origin of this phenotype and in the formation of sequence duplications. These results demonstrate the great structural flexibility of this satellite RNA.
通过在感染辅助病毒的植物中进行扩增，对烟草环斑病毒卫星RNA的接头插入-缺失突变体的复制特性进行了研究。对应于复制形式的cDNA序列分析表明，原始突变分子中只有一个未改变地进行复制，并且一般会积累新的变体。根据原始突变的位置，观察到三种类型的序列修饰：（i）突变区域的缺失，随后是序列重复；（ii）突变区域外的序列重复和缺失；（iii）突变位点处的有限重排。未发生序列变化而进行复制的突变体积累了线性多聚体形式，这表明自我切割受到影响，尽管序列改变不涉及锤头催化结构域。替代RNA构象可能在该表型的起源和序列重复的形成中起作用。这些结果证明了这种卫星RNA具有很大的结构灵活性。
