菌根DnaQ是一种替代校对器,可以确保DNA复制的真实性
Ming-Zhi Deng1,2, Qingyun Liu3,2, Shu-Jun Cui1,4
1Key Laboratory of Medical Molecular Virology of the Ministry of Education/Ministry of Health (MOE/NHC), School of Basic Medical Sciences, Fudan University, Shanghai 200032, P.R.China.
bioRxiv : the preprint server for biology
|November 14, 2023
概括
菌根菌使用两个校对器来检测DNA复制的真实性. 一种替代的DnaQ蛋白,通常被抑制,纠正错误,与药物耐药性相关的变体.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 微生物学 微生物学
背景情况:
- 为了防止突变,DNA复制忠实度至关重要.
- 虽然大肠杆菌使用DnaQ (ε-外核酶) 进行校对,但真菌细菌主要依赖其复制性聚合酶的PHP域.
- 在菌根菌中存在另一种DnaQ同类物,但其在校对中的作用尚不清楚.
研究的目的:
- 为了研究替代DnaQ同源在菌根细菌DNA复制中的功能.
- 确定DnaQ是否有助于维护菌根菌中的复制忠实性.
- 探索DnaQ变异在临床Mycobacterium结核病分离物中的影响.
主要方法:
- 在Mycolicibacterium smegmatis中DnaQ的耗尽.
- 突变速率分析,包括AT偏差和同聚合物通道中的indel检测.
- 研究DnaQ与β的相互作用及其与PHP域的协同功能.
- 在染色体拓应激下评估DnaQ的作用.
- 从临床Mycobacterium结核病分离物中自然演化的DnaQ变体的分析.
主要成果:
- 在M. smegmatis中,DnaQ的耗尽增加了突变率,导致AT偏向的突变发生,并在同聚合物区域中增加了插入/删除.
- 证明Mycobacterial DnaQ可以结合β并与PHP域一起工作以修复复制错.
- 即使染色体处于拓压力之下,DnaQ也保持了复制忠诚度.
- 在临床M.结核病分离物中常见的DnaQ变体促进了超变性,并与广泛的耐药性相关.
结论:
- 替代的DnaQ蛋白质在真菌细菌中起到校对者的作用.
- 我的细菌采用双校对系统,涉及PHP域和DnaQ,以确保高复制效率.
- 鉴定到的DnaQ变体突显出一种快速适应的机制,以及与M.结核病抗菌素耐药性的潜在联系.
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