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Lee SM, Le HT, Taizhanova A, Nong LK, Park JY, Lee EJ, Palsson BO, Kim D. Experimental promoter identification of a foodborne pathogen Salmonella enterica subsp. enterica serovar Typhimurium with near single base-pair resolution. Front Microbiol 2024; 14:1271121. [PMID: 38239730 PMCID: PMC10794520 DOI: 10.3389/fmicb.2023.1271121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 12/01/2023] [Indexed: 01/22/2024] Open
Abstract
Salmonella enterica serovar Typhimurium (S. Typhimurium) is a common foodborne pathogen which is frequently used as the reference strain for Salmonella. Investigating the sigma factor network and protomers is crucial to understand the genomic and transcriptomic properties of the bacterium. Its promoters were identified using various methods such as dRNA-seq, ChIP-chip, or ChIP-Seq. However, validation using ChIP-exo, which exhibits higher-resolution performance compared to conventional ChIP, has not been conducted to date. In this study, using the representative strain S. Typhimurium LT2 (LT2), the ChIP-exo experiment was conducted to accurately determine the binding sites of catalytic RNA polymerase subunit RpoB and major sigma factors (RpoD, RpoN, RpoS, and RpoE) during exponential phase. Integrated with the results of RNA-Seq, promoters and sigmulons for the sigma factors and their association with RpoB have been discovered. Notably, the overlapping regions among binding sites of each alternative sigma factor were found. Furthermore, comparative analysis with Escherichia coli str. K-12 substr. MG1655 (MG1655) revealed conserved binding sites of RpoD and RpoN across different species. In the case of small RNAs (sRNAs), 50 sRNAs observed their expression during the exponential growth of LT2. Collectively, the integration of ChIP-exo and RNA-Seq enables genome-scale promoter mapping with high resolution and facilitates the characterization of binding events of alternative sigma factors, enabling a comprehensive understanding of the bacterial sigma factor network and condition-specific active promoters.
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Affiliation(s)
- Sang-Mok Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Hoa Thi Le
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Assiya Taizhanova
- Department of Genetic Engineering and Graduate School of Biotechnology, College of Life Sciences, Kyung Hee University, Yongin, Republic of Korea
| | - Linh Khanh Nong
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Joon Young Park
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Eun-Jin Lee
- Department of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Bernhard O. Palsson
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
| | - Donghyuk Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
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Sheremetieva M, Anufriev K, Khlebodarova T, Kolchanov N, Yanenko A. Rational metabolic engineering of Corynebacterium glutamicum to create a producer of L-valine. Vavilovskii Zhurnal Genet Selektsii 2022; 26:743-757. [PMID: 36694718 PMCID: PMC9834717 DOI: 10.18699/vjgb-22-90] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 10/26/2022] [Accepted: 10/26/2022] [Indexed: 01/06/2023] Open
Abstract
L-Valine is one of the nine amino acids that cannot be synthesized de novo by higher organisms and must come from food. This amino acid not only serves as a building block for proteins, but also regulates protein and energy metabolism and participates in neurotransmission. L-Valine is used in the food and pharmaceutical industries, medicine and cosmetics, but primarily as an animal feed additive. Adding L-valine to feed, alone or mixed with other essential amino acids, allows for feeds with lower crude protein content, increases the quality and quantity of pig meat and broiler chicken meat, as well as improves reproductive functions of farm animals. Despite the fact that the market for L-valine is constantly growing, this amino acid is not yet produced in our country. In modern conditions, the creation of strains-producers and organization of L-valine production are especially relevant for Russia. One of the basic microorganisms most commonly used for the creation of amino acid producers, along with Escherichia coli, is the soil bacterium Corynebacterium glutamicum. This review is devoted to the analysis of the main strategies for the development of L- valine producers based on C. glutamicum. Various aspects of L-valine biosynthesis in C. glutamicum are reviewed: process biochemistry, stoichiometry and regulation, enzymes and their corresponding genes, export and import systems, and the relationship of L-valine biosynthesis with central cell metabolism. Key genetic elements for the creation of C. glutamicum-based strains-producers are identified. The use of metabolic engineering to enhance L-valine biosynthesis reactions and to reduce the formation of byproducts is described. The prospects for improving strains in terms of their productivity and technological characteristics are shown. The information presented in the review can be used in the production of producers of other amino acids with a branched side chain, namely L-leucine and L-isoleucine, as well as D-pantothenate.
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Affiliation(s)
| | - K.E. Anufriev
- NRC “Kurchatov Institute”, Kurchatov Genomic Center, Moscow, Russia
| | - T.M. Khlebodarova
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, RussiaKurchatov Genomic Center of ICG SB RAS, Novosibirsk, Russia
| | - N.A. Kolchanov
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, RussiaKurchatov Genomic Center of ICG SB RAS, Novosibirsk, Russia
| | - A.S. Yanenko
- NRC “Kurchatov Institute”, Kurchatov Genomic Center, Moscow, Russia
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3
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Golubyatnikov V, Akinshin A, Ayupova N, Minushkina L. Stratifications and foliations in phase portraits of gene network models. Vavilovskii Zhurnal Genet Selektsii 2022; 26:758-764. [PMID: 36694713 PMCID: PMC9837163 DOI: 10.18699/vjgb-22-91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/20/2022] [Accepted: 09/21/2022] [Indexed: 01/06/2023] Open
Abstract
Periodic processes of gene network functioning are described with good precision by periodic trajectories (limit cycles) of multidimensional systems of kinetic-type differential equations. In the literature, such systems are often called dynamical, they are composed according to schemes of positive and negative feedback between components of these networks. The variables in these equations describe concentrations of these components as functions of time. In the preparation of numerical experiments with such mathematical models, it is useful to start with studies of qualitative behavior of ensembles of trajectories of the corresponding dynamical systems, in particular, to estimate the highest likelihood domain of the initial data, to solve inverse problems of parameter identification, to list the equilibrium points and their characteristics, to localize cycles in the phase portraits, to construct stratification of the phase portraits to subdomains with different qualities of trajectory behavior, etc. Such an à priori geometric analysis of the dynamical systems is quite analogous to the basic section "Investigation of functions and plot of their graphs" of Calculus, where the methods of qualitative studies of shapes of curves determined by equations are exposed. In the present paper, we construct ensembles of trajectories in phase portraits of some dynamical systems. These ensembles are 2-dimensional surfaces invariant with respect to shifts along the trajectories. This is analogous to classical construction in analytic mechanics, i. e. the level surfaces of motion integrals (energy, kinetic moment, etc.). Such surfaces compose foliations in phase portraits of dynamical systems of Hamiltonian mechanics. In contrast with this classical mechanical case, the foliations considered in this paper have singularities: all their leaves have a non-empty intersection, they contain limit cycles on their boundaries. Description of the phase portraits of these systems at the level of their stratifications, and that of ensembles of trajectories allows one to construct more realistic gene network models on the basis of methods of statistical physics and the theory of stochastic differential equations.
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Affiliation(s)
- V.P. Golubyatnikov
- Sobolev Institute of Mathematics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, RussiaNovosibirsk State University, Novosibirsk, Russia
| | - A.A. Akinshin
- Huawei Russian Research Institute, St. Petersburg, Russia
| | - N.B. Ayupova
- Sobolev Institute of Mathematics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, RussiaNovosibirsk State University, Novosibirsk, Russia
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4
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Blumenstein J, Rädisch R, Štěpánek V, Grulich M, Dostálová H, Pátek M. Identification of Rhodococcus erythropolis Promoters Controlled by Alternative Sigma Factors Using In Vivo and In Vitro Systems and Heterologous RNA Polymerase. Curr Microbiol 2022; 79:55. [PMID: 34982253 DOI: 10.1007/s00284-021-02747-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 12/10/2021] [Indexed: 11/03/2022]
Abstract
Rhodococcus erythropolis CCM2595 is a bacterial strain, which has been studied for its capability to degrade phenol and other toxic aromatic compounds. Its cell wall contains mycolic acids, which are also an attribute of other bacteria of the Mycolata group, such as Corynebacterium and Mycobacterium species. We suppose that many genes upregulated by phenol stress in R. erythropolis are controlled by the alternative sigma factors of RNA polymerase, which are active in response to the cell envelope or oxidative stress. We developed in vitro and in vivo assays to examine the connection between the stress sigma factors and genes activated by various extreme conditions, e.g., heat, cell surface, and oxidative stress. These assays are based on the procedures of such tests carried out in the related species, Corynebacterium glutamicum. We showed that the R. erythropolis CCM2595 genes frmB1 and frmB2, which encode S-formylglutathione hydrolases (named corynomycolyl transferases in C. glutamicum), are controlled by SigD, just like the homologous genes cmt1 and cmt2 in C. glutamicum. The new protocol of the in vivo and in vitro assays will enable us to classify R. erythropolis promoters according to their connection to sigma factors and to assign the genes to the corresponding sigma regulons. The complex stress responses, such as that induced by phenol, could, thus, be analyzed with respect to the gene regulation by sigma factors.
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Affiliation(s)
- Jan Blumenstein
- Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.,Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Robert Rädisch
- Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.,Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Václav Štěpánek
- Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic
| | - Michal Grulich
- Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic
| | - Hana Dostálová
- Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic
| | - Miroslav Pátek
- Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.
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5
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OUP accepted manuscript. FEMS Microbiol Lett 2022; 369:6528914. [DOI: 10.1093/femsle/fnac014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 01/13/2022] [Accepted: 02/13/2022] [Indexed: 11/14/2022] Open
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Busche T, Dostálová H, Rucká L, Holátko J, Barvík I, Štěpánek V, Pátek M, Kalinowski J. Overlapping SigH and SigE sigma factor regulons in Corynebacterium glutamicum. Front Microbiol 2022; 13:1059649. [PMID: 36925999 PMCID: PMC10012870 DOI: 10.3389/fmicb.2022.1059649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 11/15/2022] [Indexed: 03/06/2023] Open
Abstract
The sigma H (σΗ) and sigma E (σE) subunits of Corynebacterium glutamicum RNA polymerase belong to Group 4 of sigma factors, also called extracytoplasmic function (ECF) sigma factors. Genes of the C. glutamicum σΗ regulon that are involved in heat and oxidative stress response have already been defined, whereas the genes of the σE regulon, which is involved in cell surface stress response, have not been explored until now. Using the C. glutamicum RES167 strain and its derivative C. glutamicum ΔcseE with a deletion in the anti-σΕ gene, differential gene expression was analyzed by RNA sequencing. We found 296 upregulated and 398 downregulated genes in C. glutamicum ΔcseE compared to C. glutamicum RES167. To confirm the functional link between σΕ and the corresponding promoters, we tested selected promoters using the in vivo two-plasmid system with gfpuv as a reporter gene and by in vitro transcription. Analyses with RNAP+σΗ and RNAP+σΕ, which were previously shown to recognize similar promoters, proved that the σΗ and σE regulons significantly overlap. The σE-controlled genes were found to be involved for example in protein quality control (dnaK, dnaJ2, clpB, and clpC), the regulation of Clp proteases (clgR), and membrane integrity maintenance. The single-promoter analyses with σΗ and σΕ revealed that there are two groups of promoters: those which are exclusively σΗ-specific, and the other group of promoters, which are σΗ/σE-dependent. No exclusively σE-dependent promoter was detected. We defined the consensus sequences of exclusively σΗ-regulated promotors to be -35 GGAAt and - 10 GTT and σΗ/σE-regulated promoters to be -35 GGAAC and - 10 cGTT. Fifteen genes were found to belong to the σΗ/σΕ regulon. Homology modeling showed that there is a specific interaction between Met170 in σΗ and the nucleotides -31 and - 30 within the non-coding strand (AT or CT) of the σΗ-dependent promoters. In σE, Arg185 was found to interact with the nucleotides GA at the same positions in the σE-dependent promoters.
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Affiliation(s)
- Tobias Busche
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany.,Medical School East Westphalia-Lippe, Bielefeld University, Bielefeld, Germany
| | - Hana Dostálová
- Institute of Microbiology, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Lenka Rucká
- Institute of Microbiology, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Jiří Holátko
- Institute of Microbiology, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Ivan Barvík
- Faculty of Mathematics and Physics, Institute of Physics, Charles University, Prague, Czechia
| | - Václav Štěpánek
- Institute of Microbiology, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Miroslav Pátek
- Institute of Microbiology, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
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7
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Jeong H, Kim Y, Lee HS. OsnR is an autoregulatory negative transcription factor controlling redox-dependent stress responses in Corynebacterium glutamicum. Microb Cell Fact 2021; 20:203. [PMID: 34663317 PMCID: PMC8524982 DOI: 10.1186/s12934-021-01693-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 10/07/2021] [Indexed: 01/11/2023] Open
Abstract
Background Corynebacterium glutamicum is used in the industrial production of amino acids and nucleotides. During the course of fermentation, C. glutamicum cells face various stresses and employ multiple regulatory genes to cope with the oxidative stress. The osnR gene plays a negative regulatory role in redox-dependent oxidative-stress responses, but the underlying mechanism is not known yet. Results Overexpression of the osnR gene in C. glutamicum affected the expression of genes involved in the mycothiol metabolism. ChIP-seq analysis revealed that OsnR binds to the promoter region of multiple genes, including osnR and cg0026, which seems to function in the membrane-associated redox metabolism. Studies on the role of the osnR gene involving in vitro assays employing purified OsnR proteins and in vivo physiological analyses have identified that OsnR inhibits the transcription of its own gene. Further, oxidant diamide stimulates OsnR-binding to the promoter region of the osnR gene. The genes affected by the overexpression of osnR have been found to be under the control of σH. In the osnR-overexpressing strain, the transcription of sigH is significantly decreased and the stimulation of sigH transcription by external stress is lost, suggesting that osnR and sigH form an intimate regulatory network. Conclusions Our study suggests that OsnR not only functions as a transcriptional repressor of its own gene and of those involved in redox-dependent stress responses but also participates in the global transcriptional regulation by controlling the transcription of other master regulators, such as sigH. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01693-1.
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Affiliation(s)
- Haeri Jeong
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Republic of Korea
| | - Younhee Kim
- Department of Korean Medicine, Semyung University, Jecheon, Chungbuk, Republic of Korea
| | - Heung-Shick Lee
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Republic of Korea.
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Huang J, Chen J, Wang Y, Shi T, Ni X, Pu W, Liu J, Zhou Y, Cai N, Han S, Zheng P, Sun J. Development of a Hyperosmotic Stress Inducible Gene Expression System by Engineering the MtrA/MtrB-Dependent NCgl1418 Promoter in Corynebacterium glutamicum. Front Microbiol 2021; 12:718511. [PMID: 34367120 PMCID: PMC8334368 DOI: 10.3389/fmicb.2021.718511] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 06/28/2021] [Indexed: 11/13/2022] Open
Abstract
Corynebacterium glutamicum is an important workhorse for industrial production of diversiform bioproducts. Precise regulation of gene expression is crucial for metabolic balance and enhancing production of target molecules. Auto-inducible promoters, which can be activated without expensive inducers, are ideal regulatory tools for industrial-scale application. However, few auto-inducible promoters have been identified and applied in C. glutamicum. Here, a hyperosmotic stress inducible gene expression system was developed and used for metabolic engineering of C. glutamicum. The promoter of NCgl1418 (P NCgl1418 ) that was activated by the two-component signal transduction system MtrA/MtrB was found to exhibit a high inducibility under hyperosmotic stress conditions. A synthetic promoter library was then constructed by randomizing the flanking and space regions of P NCgl1418 , and mutant promoters exhibiting high strength were isolated via fluorescence activated cell sorting (FACS)-based high-throughput screening. The hyperosmotic stress inducible gene expression system was applied to regulate the expression of lysE encoding a lysine exporter and repress four genes involved in lysine biosynthesis (gltA, pck, pgi, and hom) by CRISPR interference, which increased the lysine titer by 64.7% (from 17.0 to 28.0 g/L) in bioreactors. The hyperosmotic stress inducible gene expression system developed here is a simple and effective tool for gene auto-regulation in C. glutamicum and holds promise for metabolic engineering of C. glutamicum to produce valuable chemicals and fuels.
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Affiliation(s)
- Jingwen Huang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China.,Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jiuzhou Chen
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Yu Wang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Tuo Shi
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Xiaomeng Ni
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Wei Pu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jiao Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Yingyu Zhou
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Ningyun Cai
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Shuangyan Han
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Ping Zheng
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jibin Sun
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China.,Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
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9
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Henke NA, Krahn I, Wendisch VF. Improved Plasmid-Based Inducible and Constitutive Gene Expression in Corynebacterium glutamicum. Microorganisms 2021; 9:204. [PMID: 33478126 PMCID: PMC7835838 DOI: 10.3390/microorganisms9010204] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 01/15/2021] [Accepted: 01/18/2021] [Indexed: 01/18/2023] Open
Abstract
Corynebacterium glutamicum has been safely used in white biotechnology for the last 60 years and the portfolio of new pathways and products is increasing rapidly. Hence, expression vectors play a central role in discovering endogenous gene functions and in establishing heterologous gene expression. In this work, new expression vectors were designed based on two strategies: (i) a library screening of constitutive native and synthetic promoters and (ii) an increase of the plasmid copy number. Both strategies were combined and resulted in a very strong expression and overproduction of the fluorescence protein GfpUV. As a second test case, the improved vector for constitutive expression was used to overexpress the endogenous xylulokinase gene xylB in a synthetic operon with xylose isomerase gene xylA from Xanthomonas campestris. The xylose isomerase activity in crude extracts was increased by about three-fold as compared to that of the parental vector. In terms of application, the improved vector for constitutive xylA and xylB expression was used for production of the N-methylated amino acid sarcosine from monomethylamine, acetate, and xylose. As a consequence, the volumetric productivity of sarcosine production was 50% higher as compared to that of the strain carrying the parental vector.
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Affiliation(s)
| | | | - Volker F. Wendisch
- Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, 33615 Bielefeld, Germany; (N.A.H.); (I.K.)
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10
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Ruwe M, Persicke M, Busche T, Müller B, Kalinowski J. Physiology and Transcriptional Analysis of (p)ppGpp-Related Regulatory Effects in Corynebacterium glutamicum. Front Microbiol 2019; 10:2769. [PMID: 31849906 PMCID: PMC6892785 DOI: 10.3389/fmicb.2019.02769] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 11/13/2019] [Indexed: 12/20/2022] Open
Abstract
The alarmone species ppGpp and pppGpp are elementary components of bacterial physiology as they both coordinate the bacterial stress response and serve as fine-tuners of general metabolism during conditions of balanced growth. Since the regulation of (p)ppGpp metabolism and the effects of (p)ppGpp on cellular processes are highly complex and show massive differences between bacterial species, the underlying molecular mechanisms have so far only been insufficiently investigated for numerous microorganisms. In this study, (p)ppGpp physiology in the actinobacterial model organism Corynebacterium glutamicum was analyzed by phenotypic characterization and RNAseq-based transcriptome analysis. Total nutrient starvation was identified as the most effective method to induce alarmone production, whereas traditional induction methods such as the addition of serine hydroxamate (SHX) or mupirocin did not show a strong accumulation of (p)ppGpp. The predominant alarmone in C. glutamicum represents guanosine tetraphosphate, whose stress-associated production depends on the presence of the bifunctional RSH enzyme Rel. Interestingly, in addition to ppGpp, another substance yet not identified accumulated strongly under inducing conditions. A C. glutamicum triple mutant (Δrel,ΔrelS,ΔrelH) unable to produce alarmones [(p)ppGpp0 strain] exhibited unstable growth characteristics and interesting features such as an influence of illumination on its physiology, production of amino acids as well as differences in vitamin and carotenoid production. Differential transcriptome analysis using RNAseq provided numerous indications for the molecular basis of the observed phenotype. An evaluation of the (p)ppGpp-dependent transcriptional regulation under total nutrient starvation revealed a complex interplay with the involvement of ribosome-mediated transcriptional attenuation, the stress-responsive sigma factors σB and σH and transcription factors such as McbR, the master regulator of sulfur metabolism. In addition to the differential regulation of genes connected with various cell functions, the transcriptome analysis revealed conserved motifs within the promoter regions of (p)ppGpp-dependently and independently regulated genes. In particular, the representatives of translation-associated genes are both (p)ppGpp-dependent transcriptionally downregulated and show a highly conserved and so far unknown TTTTG motif in the -35 region, which is also present in other actinobacterial genera.
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Affiliation(s)
- Matthias Ruwe
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Marcus Persicke
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Tobias Busche
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | | | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
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11
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Casas Garcia GP, Perugini MA, Lamont IL, Maher MJ. The purification of the σ FpvI/FpvR 20 and σ PvdS/FpvR 20 protein complexes is facilitated at room temperature. Protein Expr Purif 2019; 160:11-18. [PMID: 30878602 DOI: 10.1016/j.pep.2019.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/07/2019] [Accepted: 03/11/2019] [Indexed: 10/27/2022]
Abstract
Bacteria contain sigma (σ) factors that control gene expression in response to various environmental stimuli. The alternative sigma factors σFpvI and σPvdS bind specifically to the antisigma factor FpvR. These proteins are an essential component of the pyoverdine-based system for iron uptake in Pseudomonas aeruginosa. Due to the uniqueness of this system, where the activities of both the σFpvI and σPvdS sigma factors are regulated by the same antisigma factor, the interactions between the antisigma protein FpvR20 and the σFpvI and σPvdS proteins have been widely studied in vivo. However, difficulties in obtaining soluble, recombinant preparations of the σFpvI and σPvdS proteins have limited their biochemical and structural characterizations. In this study, we describe a purification protocol that resulted in the production of soluble, recombinant His6-σFpvI/FpvR1-67, His6-σFpvI/FpvR1-89, His6-σPvdS/FpvR1-67 and His6-σPvdS/FpvR1-89 protein complexes (where FpvR1-67 and FpvR1-89 are truncated versions of FpvR20) at high purities and concentrations, appropriate for biophysical analyses by circular dichroism spectroscopy and analytical ultracentrifugation. These results showed the proteins to be folded in solution and led to the determination of the affinities of the protein-protein interactions within the His6-σFpvI/FpvR1-67 and His6-σPvdS/FpvR1-67 complexes. A comparison of these values with those previously reported for the His6-σFpvI/FpvR1-89 and His6-σPvdS/FpvR1-89 complexes is made.
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Affiliation(s)
- G Patricia Casas Garcia
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Matthew A Perugini
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Iain L Lamont
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Megan J Maher
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia.
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Xu N, Wei L, Liu J. Recent advances in the applications of promoter engineering for the optimization of metabolite biosynthesis. World J Microbiol Biotechnol 2019; 35:33. [DOI: 10.1007/s11274-019-2606-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/23/2019] [Indexed: 01/24/2023]
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Dostálová H, Busche T, Holátko J, Rucká L, Štěpánek V, Barvík I, Nešvera J, Kalinowski J, Pátek M. Overlap of Promoter Recognition Specificity of Stress Response Sigma Factors SigD and SigH in Corynebacterium glutamicum ATCC 13032. Front Microbiol 2019; 9:3287. [PMID: 30687273 PMCID: PMC6338062 DOI: 10.3389/fmicb.2018.03287] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 12/17/2018] [Indexed: 12/27/2022] Open
Abstract
Corynebacterium glutamicum ATCC 13032 harbors five sigma subunits of RNA polymerase belonging to Group IV, also called extracytoplasmic function (ECF) σ factors. These factors σC, σD, σE, σH, and σM are mostly involved in stress responses. The role of σD consists in the control of cell wall integrity. The σD regulon is involved in the synthesis of components of the mycomembrane which is part of the cell wall in C. glutamicum. RNA sequencing of the transcriptome from a strain overexpressing the sigD gene provided 29 potential σD-controlled genes and enabled us to precisely localize their transcriptional start sites. Analysis of the respective promoters by both in vitro transcription and the in vivo two-plasmid assay confirmed that transcription of 11 of the tested genes is directly σD-dependent. The key sequence elements of all these promoters were found to be identical or closely similar to the motifs -35 GTAACA/G and -10 GAT. Surprisingly, nearly all of these σD-dependent promoters were also active to a much lower extent with σHin vivo and one (Pcg0607) also in vitro, although the known highly conserved consensus sequence of the σH-dependent promoters is different (-35 GGAAT/C and -10 GTT). In addition to the activity of σH at the σD-controlled promoters, we discovered separated or overlapping σA- or σB-regulated or σH-regulated promoters within the upstream region of 8 genes of the σD-regulon. We found that phenol in the cultivation medium acts as a stress factor inducing expression of some σD-dependent genes. Computer modeling revealed that σH binds to the promoter DNA in a similar manner as σD to the analogous promoter elements. The homology models together with mutational analysis showed that the key amino acids, Ala 60 in σD and Lys 53 in σH, bind to the second nucleotide within the respective -10 promoter elements (GAT and GTT, respectively). The presented data obtained by integrating in vivo, in vitro and in silico approaches demonstrate that most of the σD-controlled genes also belong to the σH-regulon and are also transcribed from the overlapping or closely located housekeeping (σA-regulated) and/or general stress (σB-regulated) promoters.
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Affiliation(s)
- Hana Dostálová
- Institute of Microbiology of the CAS, v. v. i., Prague, Czechia
| | - Tobias Busche
- Centrum für Biotechnologie, Universität Bielefeld, Bielefeld, Germany
| | - Jiří Holátko
- Institute of Microbiology of the CAS, v. v. i., Prague, Czechia
| | - Lenka Rucká
- Institute of Microbiology of the CAS, v. v. i., Prague, Czechia
| | - Václav Štěpánek
- Institute of Microbiology of the CAS, v. v. i., Prague, Czechia
| | - Ivan Barvík
- Institute of Physics, Faculty of Mathematics and Physics, Charles University, Prague, Czechia
| | - Jan Nešvera
- Institute of Microbiology of the CAS, v. v. i., Prague, Czechia
| | - Jörn Kalinowski
- Centrum für Biotechnologie, Universität Bielefeld, Bielefeld, Germany
| | - Miroslav Pátek
- Institute of Microbiology of the CAS, v. v. i., Prague, Czechia
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Shi F, Luan M, Li Y. Ribosomal binding site sequences and promoters for expressing glutamate decarboxylase and producing γ-aminobutyrate in Corynebacterium glutamicum. AMB Express 2018; 8:61. [PMID: 29671147 PMCID: PMC5906420 DOI: 10.1186/s13568-018-0595-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 04/13/2018] [Indexed: 12/14/2022] Open
Abstract
Glutamate decarboxylase (GAD) converts l-glutamate (Glu) into γ-aminobutyric acid (GABA). Corynebacterium glutamicum that expresses exogenous GAD gene, gadB2 or gadB1, can synthesize GABA from its own produced Glu. To enhance GABA production in C. glutamicum, ribosomal binding site (RBS) sequence and promoter were searched and optimized for increasing the expression efficiency of gadB2. R4 exhibited the highest strength among RBS sequences tested, with 6 nt the optimal aligned spacing (AS) between RBS and start codon. This combination of RBS sequence and AS contributed to gadB2 expression, increased GAD activity by 156% and GABA production by 82% compared to normal strong RBS and AS combination. Then, a series of native promoters were selected for transcribing gadB2 under optimal RBS and AS combination. PdnaK, PdtsR, PodhI and PclgR expressed gadB2 and produced GABA as effectively as widely applied Ptuf and PcspB promoters and more effectively than Psod promoter. However, each native promoter did not work as well as the synthetic strong promoter PtacM, which produced 20.2 ± 0.3 g/L GABA. Even with prolonged length and bicistronic architecture, the strength of PdnaK did not enhance. Finally, gadB2 and mutant gadB1 were co-expressed under the optimal promoter and RBS combination, thus converted Glu into GABA completely and improved GABA production to more than 25 g/L. This study provides useful promoters and RBS sequences for gene expression in C. glutamicum.
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