参与表观遗传调控的细菌DNA甲基转移酶CcrM的研究进展

Research progress of bacterial DNA methyltransferase CcrM involved in epigenetic regulation

摘要:

DNA甲基化是细菌进行表观遗传调控的重要方式，α变形菌利用受细胞周期调控的DNA甲基转移酶(cell cycle-regulated DNA methyltransferase, CcrM)对DNA进行甲基化。CcrM不含限制性内切酶功能单元，属于孤儿甲基转移酶。CcrM通过对序列中腺嘌呤进行甲基化影响DNA与蛋白质的相互作用，从而调节大量基因的表达，对α变形菌细胞周期等过程的调控至关重要。本文综述了CcrM的功能、结构及其表观调控机制，阐明了CcrM对DNA的识别、催化及活性调控的机理，总结了细胞周期全局性调控因子(global cell-cycle regulator, GcrA)利用CcrM的甲基化信号调节基因表达的机制，并展望了CcrM未来的潜在研究方向，为进一步深入研究细菌表观遗传调控机制提供了参考。

Abstract:

DNA methylation is an important way of epigenetic regulation in bacteria. Alphaproteobacteria methylate DNA by using the cell cycle-regulated DNA methyltransferase (CcrM). CcrM does not contain a functional unit of restriction endonuclease, thus belonging to an orphan methyltransferase. By methylating adenine in DNA sequences, CcrM influences the interaction between DNA and proteins, regulates the expression of numerous genes, and is crucial for the regulation of processes such as the cell cycle of Alphaproteobacteria. We reviewed the function, structure, and epigenetic regulation of CcrM, clarified the mechanisms of CcrM in DNA recognition, catalysis, and activity regulation, summarized the mechanism by which the global cell-cycle regulator (GcrA) utilizes the methylation signals produced by CcrM to regulate gene expression, and provided an outlook on the potential future research directions of CcrM, providing a reference for further in-depth study of the epigenetic regulation mechanisms in bacteria.