Genomic evolution drives the evolution of the translation system
Genomic evolution drives the evolution of the translation system
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DOI：
10.1139/o95-086
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发表时间：
1995-11-01
影响因子：
2.9
通讯作者：
Kurland, CG
中科院分区：
文献类型：
--
作者：
Andersson, SGE;Kurland, CG
我们的论点是，翻译机器的特征和它的组织部分地由基因组特征的进化压力选择，与翻译本身无关。这些基因组特征包括大小、组成和结构。为了说明这一点，我们绘制了不同基因组结构之间的相似之处，这些基因组相互独立地适应了细胞内的小生境。我们的出发点是一般的观察，细胞器和寄生细菌的进化历史有利于矮脚鸡基因组。此外，我们认为，基因组进化的还原模式的限制占线粒体中的遗传密码的分歧和寄生细菌中观察到的翻译系统的遗传组织。特别是，我们将动物线粒体中的密码子重排与大大简化的tRNA群体相关联。同样，我们与专性细胞内寄生虫普氏立克次体的翻译基因的组织支持基因组进化的还原模式的过程。这些发现为以下假设提供了强有力的支持：细胞器和寄生细菌的基因组是由祖先细菌的更大的基因组产生的，这些基因组已被染色体内重组和缺失事件减少。基因组进化的还原模式的一个后果是，所产生的翻译系统可能会显着偏离传统的系统。
Our thesis is that the characteristics of the translational machinery and its organization are selected in part by evolutionary pressure on genomic traits have nothing to do with translation per se. These genomic traits include size, composition, and architecture. To illustrate this point, we draw parallels between the structures of different genomes that have adapted to intracellular niches independently of each other. Our starting point is the general observation that the evolutionary history of organellar and parasitic bacteria have favored bantam genomes. Furthermore, we suggest that the constraints of the reductive mode of genomic evolution account for the divergence of the genetic code in mitochondria and the genetic organization of the translational system observed in parasitic bacteria. In particular, we associate codon reassignments in animal mitochondria with greatly simplified tRNA populations. Likewise, we relate the organization of translational genes in the obligate intracellular parasite Rickettsia prowazekii to the processes supporting the reductive mode of genomic evolution. Such findings provide strong support for the hypothesis that genomes of organelles and of parasitic bacteria have arisen from the much larger genomes of ancestral bacteria that have been reduced by intrachromosomal recombination and deletion events. A consequence of the reductive mode of genomic evolution is that the resulting translation systems may deviate markedly from conventional systems.