The origins and early evolution of DNA mismatch repair genes--multiple horizontal gene transfers and co-evolution.
The origins and early evolution of DNA mismatch repair genes--multiple horizontal gene transfers and co-evolution.
复制标题
DNA不匹配修复基因的起源和早期进化 - 多个水平基因转移和共进化。
DOI：
10.1093/nar/gkm921
复制
发表时间：
2007
影响因子：
14.9
通讯作者：
Ma, Hong
中科院分区：
文献类型：
--
作者：
Lin, Zhenguo;Nei, Masatoshi;Ma, Hong
为了了解DNA错配修复系统的进化过程，我们对其关键组成部分细菌MutS和MutL基因及其真核同系物进行了系统的系统发育分析。基于全基因组同源性搜索，除了先前研究的MutS1和MutS2亚家族外，我们还发现了三个新的mutts亚家族（MutS3-5）。详细的进化分析强烈表明，频繁的古代水平基因转移（HGT）发生在MutS和MutL基因从细菌到真核生物和/或古细菌的过程中。我们的研究结果进一步表明，真核生物和古细菌错配修复系统的起源在很大程度上归因于来自细菌的古老HGT，而不是垂直进化。具体来说，真核MutS和MutL同源物可能起源于线粒体或叶绿体的内共生祖先，这表明不仅是古细菌，细菌也是真核DNA代谢基因的重要来源。通过HGT同时从细菌中获得了古细菌MutS1和MutL的同源物。此外，MutS1和MutL基因的分布和进化特征表明它们经历了长期的共同进化。我们的工作呈现了这些重要基因在DNA代谢中的进化的整体肖像，也提供了对细胞生物早期进化的进一步理解。
To understand the evolutionary process of the DNA mismatch repair system, we conducted systematic phylogenetic analysis of its key components, the bacterial MutS and MutL genes and their eukaryotic homologs. Based on genome-wide homolog searches, we identified three new MutS subfamilies (MutS3-5) in addition to the previously studied MutS1 and MutS2 subfamilies. Detailed evolutionary analysis strongly suggests that frequent ancient horizontal gene transfer (HGT) occurred with both MutS and MutL genes from bacteria to eukaryotes and/or archaea. Our results further imply that the origins of mismatch repair system in eukaryotes and archaea are largely attributed to ancient HGT from bacteria instead of vertical evolution. Specifically, the eukaryotic MutS and MutL homologs likely originated from endosymbiotic ancestors of mitochondria or chloroplasts, indicating that not only archaea, but also bacteria are important sources of eukaryotic DNA metabolic genes. The archaeal MutS1 and MutL homologs were also acquired from bacteria simultaneously through HGT. Moreover, the distribution and evolution profiles of the MutS1 and MutL genes suggest that they have undergone long-term coevolution. Our work presents an overall portrait of the evolution of these important genes in DNA metabolism and also provides further understanding about the early evolution of cellular organisms.