Molecular evolution of the actin-like MreB protein gene family in wall-less bacteria
Molecular evolution of the actin-like MreB protein gene family in wall-less bacteria
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DOI：
10.1016/j.bbrc.2014.03.039
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发表时间：
2014-04-18
影响因子：
3.1
通讯作者：
Kuo, Chih-Horng
中科院分区：
文献类型：
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作者：
Ku, Chuan;Lo, Wen-Sui;Kuo, Chih-Horng
mreB 基因家族编码肌动蛋白样蛋白，通过指导细胞壁合成来确定细胞形状，并且通常以一到三个拷贝存在于非球形细菌的基因组中。有趣的是，虽然大多数无壁细菌不具有该基因，但在螺原体和盐原体中发现了五到七个 mreB 同源物，这两种细菌都具有细胞收缩性。为了研究无壁细菌中该基因家族的分子进化，我们对这两个属和其他相关谱系的可用基因组序列进行了采样，以进行比较分析。基因系统发育表明，盐原体中的 mreB 同源物与厚壁菌门中的 mreB 同源物关系更密切，而螺原体中的 mreB 同源物形成一个单独的进化枝。 This finding suggests that the gene family expansions in these two lineages are the results of independent ancient duplications. Moreover, the Spiroplasma mreB homologs can be classified into five clades, of which the genomic positions are largely conserved.基因获得和丢失的推论表明，在螺原体进化史上，总体趋势是五个 mreB 进化枝中的每一个仅保留一个同源物。 (C) 2014 年作者。由爱思唯尔公司出版
The mreB gene family encodes actin-like proteins that determine cell shape by directing cell wall synthesis and often exists in one to three copies in the genomes of non-spherical bacteria. Intriguingly, while most wall-less bacteria do not have this gene, five to seven mreB homologs are found in Spiroplasma and Haloplasma, which are both characterized by cell contractility. To investigate the molecular evolution of this gene family in wall-less bacteria, we sampled the available genome sequences from these two genera and other related lineages for comparative analysis. The gene phylogenies indicated that the mreB homologs in Haloplasma are more closely related to those in Firmicutes, whereas those in Spiroplasma form a separate clade. This finding suggests that the gene family expansions in these two lineages are the results of independent ancient duplications. Moreover, the Spiroplasma mreB homologs can be classified into five clades, of which the genomic positions are largely conserved. The inference of gene gains and losses suggests that there has been an overall trend to retain only one homolog from each of the five mreB clades in the evolutionary history of Spiroplasma. (C) 2014 The Authors. Published by Elsevier Inc.