The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
Institute of Future Food Technology, JITRI, Yixing 214200, China.
Nucleic Acids Res. 2024 Aug 12;52(14):8609-8627. doi: 10.1093/nar/gkae577.
High spontaneous mutation rate is crucial for obtaining ideal phenotype and exploring the relationship between genes and phenotype. How to break the genetic stability of organisms and increase the mutation frequency has become a research hotspot. Here, we present a practical and controllable evolutionary tool (oMut-Cgts) based on dual genetic level modification engineering for Corynebacterium glutamicum. Firstly, the modification engineering of transcription and replication levels based on RNA polymerase α subunit and DNA helicase Cgl0854 as the 'dock' of cytidine deaminase (pmCDA1) significantly increased the mutation rate, proving that the localization of pmCDA1 around transient ssDNA is necessary for genome mutation. Then, the combined modification and optimization of engineering at dual genetic level achieved 1.02 × 104-fold increased mutation rate. The genome sequencing revealed that the oMut-Cgts perform uniform and efficient C:G→T:A transitions on a genome-wide scale. Furthermore, oMut-Cgts-mediated rapid evolution of C. glutamicum with stress (acid, oxidative and ethanol) tolerance proved that the tool has powerful functions in multi-dimensional biological engineering (rapid phenotype evolution, gene function mining and protein evolution). The strategies for rapid genome evolution provided in this study are expected to be applicable to a variety of applications in all prokaryotic cells.
高自发突变率对于获得理想表型和探索基因与表型之间的关系至关重要。如何打破生物体的遗传稳定性并提高突变频率已成为研究热点。在这里,我们提出了一种基于双遗传水平修饰工程的实用且可控的 Corynebacterium glutamicum 进化工具 (oMut-Cgts)。首先,基于 RNA 聚合酶 α 亚基和 DNA 解旋酶 Cgl0854 作为胞嘧啶脱氨酶 (pmCDA1) 的“码头”,对转录和复制水平进行修饰工程,显著提高了突变率,证明了 pmCDA1 定位于瞬时 ssDNA 周围对于基因组突变是必要的。然后,对双遗传水平的工程进行联合修饰和优化,实现了 1.02×104 倍的突变率增加。基因组测序表明,oMut-Cgts 在全基因组范围内均匀且有效地进行 C:G→T:A 转换。此外,oMut-Cgts 介导的具有应激(酸、氧化和乙醇)耐受性的 C. glutamicum 快速进化证明了该工具在多维生物工程(快速表型进化、基因功能挖掘和蛋白质进化)方面具有强大的功能。本研究中提供的快速基因组进化策略有望适用于所有原核细胞的各种应用。