Evolved RNA secondary structure and the rooting of the universal tree of life
Evolved RNA secondary structure and the rooting of the universal tree of life
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DOI：
10.1007/s00239-001-0048-3
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发表时间：
2002-03-01
影响因子：
3.9
通讯作者：
Caetano-Anollés, G
中科院分区：
文献类型：
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作者：
Caetano-Anollés, G
RNA二级结构的起源和多样性进行了跟踪使用分支的方法。结构组件被编码为极化和有序的多状态字符，根据统计力学的考虑概述的字符状态转换模型。分析了几类功能性RNA，包括核糖体RNA（rRNA）。它们的二级结构中存在相当大的系统发育信号。从进化的RNA结构重建的内在根源的遗传学描述了来自所有分类学水平的核酸序列的遗传学，并根据传统分类对生物进行了分组，特别是在古生菌和真核生物领域。因此，自然选择似乎在信息的早期就起作用了，这些信息起源于序列，结束于适应的表型。在研究生物世界的等级分类时，对小rRNA亚基和大rRNA亚基的二级结构的系统发育分析重建了一个通用的生命树，该生命树分支为三个单系类群，分别对应于真核生物、真核生物和细菌，并植根于真核生物的分支。参与翻译循环的核糖体特征可以很容易地追踪，并表明大rRNA亚基中的转移RNA（tRNA）结合结构域与rRNA分子的其余部分同时进化。结果表明，它是同样吝啬，认为祖先的单细胞真核生物或原核生物引起了所有现存的生命形式，并提供了一个罕见的洞察核酸和蛋白质生物合成的早期进化。
The origin and diversification of RNA secondary structure were traced using cladistic methods. Structural components were coded as polarized and ordered multi-state characters, following a model of character state transformation outlined by considerations in statistical mechanics. Several classes of functional RNA were analyzed, including ribosomal RNA (rRNA). Considerable phylogenetic signal was present in their secondary structure. The intrinsically rooted phylogenics reconstructed from evolved RNA structure depicted those derived from nucleic acid sequence at all taxonomical levels, and grouped organisms in concordance with traditional classification, especially in the archaeal and eukaryal domains. Natural selection appears therefore to operate early in the information now that originates in sequence and ends in an adapted phenotype. When examining the hierarchical classification of the living world, phylogenetic analysis of secondary structure of the small and large rRNA subunits reconstructed a universal tree of life that branched in three monophyletic groups corresponding to Eucarya, Archaea, and Bacteria, and was rooted in the eukaryotic branch. Ribosomal characters involved in the translational cycle could be easily traced and showed that transfer RNA (tRNA) binding domains in the large rRNA subunit evolved concurrently with the rest of the rRNA molecule. Results suggest it is equally parsimonious to consider that ancestral unicellular eukaryotes or prokaryotes gave rise to all extant life forms and provide a rare insight into the early evolution of nucleic acid and protein biosynthesis.