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Yu G, Duan Q, Cui T, Jiang C, Li X, Li Y, Fu J, Zhang Y, Wang H, Luan J. Development of a bacterial gene transcription activating strategy based on transcriptional activator positive feedback. J Adv Res 2023:S2090-1232(23)00400-9. [PMID: 38123018 DOI: 10.1016/j.jare.2023.12.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 11/26/2023] [Accepted: 12/16/2023] [Indexed: 12/23/2023] Open
Abstract
INTRODUCTION Transcription of biological nitrogen fixation (nif) genes is activated by the NifA protein which recognizes specific activating sequences upstream of σ54-dependent nif promoters. The large quantities of nitrogenase which can make up 20% of the total proteins in the cell indicates high transcription activating efficiency of NifA and high transcription level of nifHDK nitrogenase genes. OBJECTIVES Development of an efficient gene transcription activating strategy in bacteria based on positive transcription regulatory proteins and their regulating DNA sequences. METHODS We designed a highly efficient gene transcription activating strategy in which the nifA gene was placed directly downstream of its regulating sequences. The NifA protein binds its regulating sequences and stimulates transcription of itself and downstream genes. Overexpressed NifA causes transcription activation by positive reinforcement. RESULTS When this gene transcription activating strategy was used to overexpress NifA in Pseudomonas stutzeri DSM4166 containing the nif gene cluster, the nitrogenase activity was increased by 368 folds which was 16 times higher than that obtained by nifA driven by the strongest endogenous constitutive promoter. When this strategy was used to activate transcription of exogenous biosynthetic genes for the plant auxin indole-3-acetic acid and the antitumor alkaloid pigment prodigiosin in DSM4166, both of them resulted in better performance than the strongest endogenous constitutive promoter and the highest reported productions in heterologous hosts to date. Finally, we demonstrated the universality of this strategy using the positive transcriptional regulator of the psp operon, PspF, in E. coli and the pathway-specific positive transcription regulator of the polyene antibiotic salinomycin biosynthesis, SlnR, in Streptomyces albus. CONCLUSION Many positive transcription regulatory proteins and their regulating DNA sequences have been identified in bacteria. The gene transcription activating strategy developed in this study will have broad applications in molecular biology and biotechnology.
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Affiliation(s)
- Guangle Yu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, 266237, Qingdao, Shandong, China
| | - Qiuyue Duan
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, 266237, Qingdao, Shandong, China
| | - Tianqi Cui
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, 266237, Qingdao, Shandong, China
| | - Chanjuan Jiang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, 266237, Qingdao, Shandong, China
| | - Xiaochen Li
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, 266237, Qingdao, Shandong, China
| | - Yutong Li
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, 266237, Qingdao, Shandong, China
| | - Jun Fu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, 266237, Qingdao, Shandong, China
| | - Youming Zhang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, 266237, Qingdao, Shandong, China
| | - Hailong Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, 266237, Qingdao, Shandong, China.
| | - Ji Luan
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, 266237, Qingdao, Shandong, China.
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Yu G, Li X, Duan Q, Fu J, Zhang Y, Wang H, Luan J. Systematic identification of endogenous strong constitutive promoters from the diazotrophic rhizosphere bacterium Pseudomonas stutzeri DSM4166 to improve its nitrogenase activity. Microb Cell Fact 2023; 22:91. [PMID: 37138314 PMCID: PMC10155442 DOI: 10.1186/s12934-023-02085-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 04/09/2023] [Indexed: 05/05/2023] Open
Abstract
BACKGROUND Biological nitrogen fixation converting atmospheric dinitrogen to ammonia is an important way to provide nitrogen for plants. Pseudomonas stutzeri DSM4166 is a diazotrophic Gram-negative bacterium isolated from the rhizosphere of cereal Sorghum nutans. Endogenous constitutive promoters are important for engineering of the nitrogen fixation pathway, however, they have not been systematically characterized in DSM4166. RESULTS Twenty-six candidate promoters were identified from DSM4166 by RNA-seq analysis. These 26 promoters were cloned and characterized using the firefly luciferase gene. The strengths of nineteen promoters varied from 100 to 959% of the strength of the gentamicin resistance gene promoter. The strongest P12445 promoter was used to overexpress the biological nitrogen fixation pathway-specific positive regulator gene nifA. The transcription level of nitrogen fixation genes in DSM4166 were significantly increased and the nitrogenase activity was enhanced by 4.1 folds determined by the acetylene reduction method. The nifA overexpressed strain produced 359.1 µM of extracellular ammonium which was 25.6 times higher than that produced by the wild-type strain. CONCLUSIONS The endogenous strong constitutive promoters identified in this study will facilitate development of DSM4166 as a microbial cell factory for nitrogen fixation and production of other useful compounds.
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Affiliation(s)
- Guangle Yu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, Qingdao, Shandong, 266237, China
| | - Xiaochen Li
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, Qingdao, Shandong, 266237, China
| | - Qiuyue Duan
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, Qingdao, Shandong, 266237, China
| | - Jun Fu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, Qingdao, Shandong, 266237, China
| | - Youming Zhang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, Qingdao, Shandong, 266237, China
| | - Hailong Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, Qingdao, Shandong, 266237, China
| | - Ji Luan
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Helmholtz International Lab for Anti-infectives, Shandong University-Helmholtz Institute of Biotechnology, Shandong University, Binhai Rd 72, Qingdao, Shandong, 266237, China.
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