Developing controllable hypermutable Clostridium cells through manipulating its methyl-directed mismatch repair system----中国科学院微生物研究所

科研成果

论文题目:	Developing controllable hypermutable Clostridium cells through manipulating its methyl-directed mismatch repair system
作者:	Luan Guodong, Cai Zhen, Gong Fuyu, Dong Hongjun, Lin Zhao, Zhang Yanping, Li Yin
联系作者:	Cai Zhen, Li Yin
刊物名称:	Protein Cell
期:	11
卷:	4
页:	854-862
年份:	2013
影响因子:	3.22
论文下载:	http://link.springer.com/article/10.1007%2Fs13238-013-3079-9
摘要:	Development of controllable hypermutable cells can greatly benefit understanding and harnessing microbial evolution. However, there have not been any similar systems developed for Clostridium, an important bacterial genus. Here we report a novel two-step strategy for developing controllable hypermutable cells of Clostridium acetobutylicum, an important and representative industrial strain. Firstly, the mutS/L operon essential for methyldirected mismatch repair (MMR) activity was inactivated from the genome of C. acetobutylicum to generate hypermutable cells with over 250-fold increased mutation rates. Secondly, a proofreading control system carrying an inducibly expressed mutS/L operon was constructed. The hypermutable cells and the proofreading control system were integrated to form a controllable hypermutable system SMBMutC, of which the mutation rates can be regulated by the concentration of anhydrotetracycline (aTc). Duplication of the miniPthl-tetR module of the proofreading control system further significantly expanded the regulatory space of the mutation rates, demonstrating hypermutable Clostridium cells with controllable mutation rates are generated. The developed C. acetobutylicum strain SMBMutC2 showed higher survival capacities than the control strain facing butanol-stress, indicating greatly increased evolvability and adaptability of the controllable hypermutable cells under environmental challenges.