A phylogenetically based secondary structure for the yeast telomerase RNA
A phylogenetically based secondary structure for the yeast telomerase RNA
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DOI：
10.1016/j.cub.2004.05.054
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发表时间：
2004-07-13
期刊：
影响因子：
9.2
通讯作者：
Wellinger, RJ
中科院分区：
文献类型：
--
作者：
Dandjinou, AT;Lévesque, N;Wellinger, RJ
背景：端粒酶是一种核糖核蛋白复合物，其RNA片段决定了染色体末端特定简单序列的添加。虽然与某些人类遗传疾病相关，但基本端粒酶RNA对RNP组装的贡献仍不清楚。脊椎动物和纤毛虫端粒酶rna的系统发育分析揭示了可能组织RNP功能的蛋白质亚基的保守元件。相比之下，酵母端粒酶RNA不能适合于任何已知的结构模型，并且来自酵母菌物种的已知序列数量有限，无法预测酵母特定的保守结构。结果：我们克隆并分析了所有已知的属于“严格感觉”组的Saccharomyces物种的完整端粒酶RNA位点（TLC1）。对酿酒葡萄球菌的互补分析和成熟rna的末端映射确保了克隆序列的相关性。通过系统发育比较分析和体外酶探测，我们得到了酿酒酵母TLC1 RNA的二级结构预测。这种保守的二级结构预测包括一个可能协调DNA合成的中心结构域和至少两个对RNA稳定性和端粒酶募集重要的辅助结构域。该结构还揭示了中心核中两个环之间潜在的三级相互作用。结论：预测的酿酒酵母TLC1 RNA二级结构揭示了一种独特的折叠模式，其功能元件分离良好但保守。预测的结构现在允许一个详细的和合理设计的研究，端粒酶rnp复合体内的结构-功能关系在遗传上可处理的系统。
Background: Telomerase is a ribonucleoprotein complex whose RNA moiety dictates the addition of specific simple sequences onto chromosomes ends. While relevant for certain human genetic diseases, the contribution of the essential telomerase RNA to RNP assembly still remains unclear. Phylogenetic analyses of vertebrate and ciliate telomerase RNAs revealed conserved elements that potentially organize protein subunits for RNP function. In contrast, the yeast telomerase RNA could not be fitted to any known structural model, and the limited number of known sequences from Saccharomyces species did not permit the prediction of a yeast specific conserved structure.Results: We cloned and analyzed the complete telomerase RNA loci (TLC1) from all known Saccharomyces species belonging to the "sensu stricto" group. Complementation analyses in S. cerevisiae and end mappings of mature RNAs ensured the relevance of the cloned sequences. By using phylogenetic comparative analysis coupled with in vitro enzymatic probing, we derived a secondary structure prediction of the Saccharomyces cerevisiae TLC1 RNA. This conserved secondary structure prediction includes a central domain that is likely to orchestrate DNA synthesis and at least two accessory domains important for RNA stability and telomerase recruitment. The structure also reveals a potential tertiary interaction between two loops in the central core.Conclusions: The predicted secondary structure of the TLC1 RNA of S. cerevisiae reveals a distinct folding pattern featuring well-separated but conserved functional elements. The predicted structure now allows for a detailed and rationally designed study to the structure-function relationships within the telomerase RNP-complex in a genetically tractable system.