Faculty of Biology and Medicine, Department of Fundamental Microbiology, University of Lausanne, Quartier UNIL/Sorge, Lausanne, CH 1015, Switzerland.
Mol Microbiol. 2018 Oct;110(1):1-10. doi: 10.1111/mmi.14079. Epub 2018 Sep 28.
Alphaproteobacteria include bacteria with very different modes of life, from free-living to host-associated and pathogenic bacteria. Their genomes vary in size and organization from single circular chromosomes to multipartite genomes and are often methylated by one or more adenine or cytosine methyltransferases (MTases). These include MTases that are part of restriction/modification systems and so-called orphan MTases. The development of novel technologies accelerated the analysis of methylomes and revealed the existence of epigenetic patterns in several Alphaproteobacteria. This review describes the known functions of DNA methylation in Alphaproteobacteria and also discusses its potential drawbacks through the accidental deamination of methylated cytosines. Particular emphasis is given to the strong connection between the cell cycle-regulated orphan MTase CcrM and the complex network that controls gene expression and cell cycle progression in Alphaproteobacteria.
α-变形菌包括具有非常不同生活方式的细菌，从自由生活到宿主相关和致病性细菌。它们的基因组在大小和组织上从单个圆形染色体到多部分基因组不等，并且经常被一个或多个腺嘌呤或胞嘧啶甲基转移酶（MTases）甲基化。其中包括作为限制/修饰系统一部分的 MTases 和所谓的孤儿 MTases。新型技术的发展加速了甲基组学的分析，并揭示了几种α-变形菌中存在的表观遗传模式。本综述描述了已知的 DNA 甲基化在α-变形菌中的功能，并通过甲基化胞嘧啶的意外脱氨讨论了其潜在的缺点。特别强调了细胞周期调控的孤儿 MTase CcrM 与控制α-变形菌中基因表达和细胞周期进程的复杂网络之间的紧密联系。
