Genome-wide analysis reveals origin of transfer RNA genes from tRNA halves.
Genome-wide analysis reveals origin of transfer RNA genes from tRNA halves.
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DOI：
10.1093/molbev/mst107
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发表时间：
2013-09
影响因子：
10.7
通讯作者：
Zhixiang Zuo;D. Peng;Xiujuan Yin;Xiaoping Zhou;Hanhua Cheng;R. Zhou
中科院分区：
文献类型：
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作者：
Zhixiang Zuo;D. Peng;Xiujuan Yin;Xiaoping Zhou;Hanhua Cheng;R. Zhou
转移RNAs(TRNAs)在蛋白质生物发生中起着连接线粒体RNA和氨基酸的重要作用。在生物体中已经发现了四种类型的tRNA基因。然而，tRNAs的进化起源在很大程度上仍不清楚。在这篇文章中，我们对涵盖所有三个生命领域的不同基因组进行了深入的序列分析，以揭示tRNA基因从tRNA的一半进化的历史。在不同的生物中检测到了tRNA的半同系物，其中一些在小鼠组织中表达。连续的tRNA基因有一种类似于indels的保守模式，即越靠近侧翼的区域有更高的单核苷酸替换率，而tRNA半同系物没有这种模式。此外，当组织在体外孵育时，tRNA往往会分裂成tRNA的一半，tRNA分裂成tRNA一半的趋势可能是tRNA基因从tRNA一半进化而来的一种副作用。这些结果表明，现代tRNA通过重复元件介导的机制起源于tRNA的一半。这些发现为tRNA基因的进化起源提供了洞察力。
Transfer RNAs (tRNAs) play an important role linking mitochondrial RNA and amino acids during protein biogenesis. Four types of tRNA genes have been identified in living organisms. However, the evolutionary origin of tRNAs remains largely unknown. In this article, we conduct a deep sequence analysis of diverse genomes that cover all three domains of life to unveil the evolutionary history of tRNA genes from tRNA halves. tRNA half homologs were detected in diverse organisms, and some of them were expressed in mouse tissues. Continuous tRNA genes have a conserved pattern similar to indels, which is, more closely flanking regions have higher single nucleotide substitution rates, whereas tRNA half homologs do not have this pattern. In addition, tRNAs tend to break into tRNA halves when tissues are incubated in vitro, the tendency of tRNA to break into tRNA halves may be a "side-effect" of tRNA genes evolving from tRNA halves. These results suggest that modern tRNAs originated from tRNA halves through a repeat element-mediated mechanism. These findings provide insight into the evolutionary origin of tRNA genes.