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Pang C, Zhang G, Liu S, Zhou J, Li J, Du G. Engineering sigma factors and chaperones for enhanced heterologous lipoxygenase production in Escherichia coli. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:105. [PMID: 36217152 PMCID: PMC9552429 DOI: 10.1186/s13068-022-02206-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/30/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Lipoxygenase (EC. 1.13.11.12, LOX) can catalyze the addition of oxygen into polyunsaturated fatty acids to produce hydroperoxides, which are widely used in the food, chemical, and pharmaceutical industries. In recent years, the heterologous production of LOX by Escherichia coli has attracted extensive attention. However, overexpressed recombinant LOX in E. coli aggregates and forms insoluble inclusion bodies owing to protein misfolding. RESULTS In this study, a split green fluorescent protein-based screening method was developed to screen sigma (σ) factors and molecular chaperones for soluble LOX expression. Three mutant libraries of Skp, GroES, and RpoH was analyzed using the high-throughput screening method developed herein, and a series of mutants with significantly higher yield of soluble heterologous LOX were obtained. The soluble expression level of LOX in the isolated mutants increased by 4.2- to 5.3-fold. Further, the highest LOX activity (up to 6240 ± 269 U·g-DCW-1) was observed in E. coli REopt, with the regulatory factor mutants, RpoH and GroES. Based on RNA-Seq analysis of the selected strains, E. coli Eopt, E. coli Sopt, E. coli Ropt, and wild type, amino acid substitutions in σ factors and molecular chaperones regulated the expression level of genes related to gene replication, recombination, and repair. Furthermore, the regulatory factor mutants were identified to be beneficial to the soluble expression of two other heterologous proteins, amylase and bone morphological protein 12. CONCLUSION In this study, a high-throughput screening method was developed for improved soluble LOX expression. The obtained positive mutants of the regulatory factor were analyzed and employed for the expression of other heterologous proteins, thus providing a potential solution for the inclusion-body protein.
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Affiliation(s)
- Cuiping Pang
- grid.258151.a0000 0001 0708 1323National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, 214122 Jiangsu China ,grid.258151.a0000 0001 0708 1323Science Center for Future Foods, Jiangnan University, Wuxi, 214122 China
| | - Guoqiang Zhang
- grid.258151.a0000 0001 0708 1323National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, 214122 Jiangsu China ,grid.258151.a0000 0001 0708 1323Science Center for Future Foods, Jiangnan University, Wuxi, 214122 China ,grid.258151.a0000 0001 0708 1323Engineering Research Center of Ministry of Education On Food Synthetic Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122 Jiangsu China
| | - Song Liu
- grid.258151.a0000 0001 0708 1323National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, 214122 Jiangsu China ,grid.258151.a0000 0001 0708 1323Science Center for Future Foods, Jiangnan University, Wuxi, 214122 China ,grid.258151.a0000 0001 0708 1323Engineering Research Center of Ministry of Education On Food Synthetic Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122 Jiangsu China
| | - Jingwen Zhou
- grid.258151.a0000 0001 0708 1323National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, 1800 Lihu Road, Wuxi, 214122 Jiangsu China ,grid.258151.a0000 0001 0708 1323Science Center for Future Foods, Jiangnan University, Wuxi, 214122 China ,grid.258151.a0000 0001 0708 1323Engineering Research Center of Ministry of Education On Food Synthetic Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122 Jiangsu China
| | - Jianghua Li
- grid.258151.a0000 0001 0708 1323Science Center for Future Foods, Jiangnan University, Wuxi, 214122 China ,grid.258151.a0000 0001 0708 1323School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122 Jiangsu China ,grid.258151.a0000 0001 0708 1323Engineering Research Center of Ministry of Education On Food Synthetic Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122 Jiangsu China
| | - Guocheng Du
- grid.258151.a0000 0001 0708 1323Science Center for Future Foods, Jiangnan University, Wuxi, 214122 China ,grid.258151.a0000 0001 0708 1323School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122 Jiangsu China ,grid.258151.a0000 0001 0708 1323Engineering Research Center of Ministry of Education On Food Synthetic Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, 214122 Jiangsu China
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Chai T, Terrettaz C, Collier J. Spatial coupling between DNA replication and mismatch repair in Caulobacter crescentus. Nucleic Acids Res 2021; 49:3308-3321. [PMID: 33677508 PMCID: PMC8034640 DOI: 10.1093/nar/gkab112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 01/19/2021] [Accepted: 02/09/2021] [Indexed: 01/14/2023] Open
Abstract
The DNA mismatch repair (MMR) process detects and corrects replication errors in organisms ranging from bacteria to humans. In most bacteria, it is initiated by MutS detecting mismatches and MutL nicking the mismatch-containing DNA strand. Here, we show that MMR reduces the appearance of rifampicin resistances more than a 100-fold in the Caulobacter crescentus Alphaproteobacterium. Using fluorescently-tagged and functional MutS and MutL proteins, live cell microscopy experiments showed that MutS is usually associated with the replisome during the whole S-phase of the C. crescentus cell cycle, while MutL molecules may display a more dynamic association with the replisome. Thus, MMR components appear to use a 1D-scanning mode to search for rare mismatches, although the spatial association between MutS and the replisome is dispensible under standard growth conditions. Conversely, the spatial association of MutL with the replisome appears as critical for MMR in C. crescentus, suggesting a model where the β-sliding clamp licences the endonuclease activity of MutL right behind the replication fork where mismatches are generated. The spatial association between MMR and replisome components may also play a role in speeding up MMR and/or in recognizing which strand needs to be repaired in a variety of Alphaproteobacteria.
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Affiliation(s)
- Tiancong Chai
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Quartier UNIL/Sorge, Lausanne, CH-1015, Switzerland
| | - Céline Terrettaz
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Quartier UNIL/Sorge, Lausanne, CH-1015, Switzerland
| | - Justine Collier
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Quartier UNIL/Sorge, Lausanne, CH-1015, Switzerland
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Jiang X, Zhang L, Teng M, Li X. Antibiotic binding releases autoinhibition of the TipA multidrug-resistance transcriptional regulator. J Biol Chem 2020; 295:17865-17876. [PMID: 33454020 PMCID: PMC7762955 DOI: 10.1074/jbc.ra120.016295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 10/21/2020] [Indexed: 11/29/2022] Open
Abstract
Investigations of bacterial resistance strategies can aid in the development of new antimicrobial drugs as a countermeasure to the increasing worldwide prevalence of bacterial antibiotic resistance. One such strategy involves the TipA class of transcription factors, which constitute minimal autoregulated multidrug resistance (MDR) systems against diverse antibiotics. However, we have insufficient information regarding how antibiotic binding induces transcriptional activation to design molecules that could interfere with this process. To learn more, we determined the crystal structure of SkgA from Caulobacter crescentus as a representative TipA protein. We identified an unexpected spatial orientation and location of the antibiotic-binding TipAS effector domain in the apo state. We observed that the α6–α7 region of the TipAS domain, which is canonically responsible for forming the lid of antibiotic-binding cleft to tightly enclose the bound antibiotic, is involved in the dimeric interface and stabilized via interaction with the DNA-binding domain in the apo state. Further structural and biochemical analyses demonstrated that the unliganded TipAS domain sterically hinders promoter DNA binding but undergoes a remarkable conformational shift upon antibiotic binding to release this autoinhibition via a switch of its α6–α7 region. Hence, the promoters for MDR genes including tipA and RNA polymerases become available for transcription, enabling efficient antibiotic resistance. These insights into the molecular mechanism of activation of TipA proteins advance our understanding of TipA proteins, as well as bacterial MDR systems, and may provide important clues to block bacterial resistance.
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Affiliation(s)
- Xuguang Jiang
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, China; Department of Cell Biology and Anatomy, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
| | - Linjuan Zhang
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, China
| | - Maikun Teng
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, China
| | - Xu Li
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, China.
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