1
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Lau MH, Madika A, Zhang Y, Minton NP. Parageobacillus thermoglucosidasius Strain Engineering Using a Theophylline Responsive RiboCas for Controlled Gene Expression. ACS Synth Biol 2024; 13:1237-1245. [PMID: 38517011 PMCID: PMC11036489 DOI: 10.1021/acssynbio.3c00735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 02/29/2024] [Accepted: 02/29/2024] [Indexed: 03/23/2024]
Abstract
The relentless increase in atmospheric greenhouse gas concentrations as a consequence of the exploitation of fossil resources compels the adoption of sustainable routes to chemical and fuel manufacture based on biological fermentation processes. The use of thermophilic chassis in such processes is an attractive proposition; however, their effective exploitation will require improved genome editing tools. In the case of the industrially relevant chassis Parageobacillus thermoglucosidasius, CRISPR/Cas9-based gene editing has been demonstrated. The constitutive promoter used, however, accentuates the deleterious nature of Cas9, causing decreased transformation and low editing efficiencies, together with an increased likelihood of off-target effects or alternative mutations. Here, we rectify this issue by controlling the expression of Cas9 through the use of a synthetic riboswitch that is dependent on the nonmetabolized, nontoxic, and cheap inducer, theophylline. We demonstrate that the riboswitches are dose-dependent, allowing for controlled expression of the target gene. Through their use, we were then able to address the deleterious nature of Cas9 and produce an inducible system, RiboCas93. The benefits of RiboCas93 were demonstrated by increased transformation efficiency of the editing vectors, improved efficiency in mutant generation (100%), and a reduction of Cas9 toxicity, as indicated by a reduction in the number of single nucleotide polymorphisms (SNPs) observed. This new system provides a quick and efficient way to produce mutants in P. thermoglucosidasius.
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Affiliation(s)
- Matthew
S. H. Lau
- BBSRC/EPSRC
Synthetic Biology Research Centre (SBRC), Biodiscovery Institute,
School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Abubakar Madika
- BBSRC/EPSRC
Synthetic Biology Research Centre (SBRC), Biodiscovery Institute,
School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
- Department
of Microbiology, Faculty of Life Sciences, Ahmadu Bello University, Zaria 810107, Nigeria
| | - Ying Zhang
- BBSRC/EPSRC
Synthetic Biology Research Centre (SBRC), Biodiscovery Institute,
School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
| | - Nigel P. Minton
- BBSRC/EPSRC
Synthetic Biology Research Centre (SBRC), Biodiscovery Institute,
School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
- NIHR
Nottingham Biomedical Research Centre, Nottingham
University Hospitals NHS Trust and The University of Nottingham, Nottingham NG7 2RD, U.K.
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2
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Xu J, Hou J, Ding M, Wang Z, Chen T. Riboswitches, from cognition to transformation. Synth Syst Biotechnol 2023; 8:357-370. [PMID: 37325181 PMCID: PMC10265488 DOI: 10.1016/j.synbio.2023.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/20/2023] [Accepted: 05/25/2023] [Indexed: 06/17/2023] Open
Abstract
Riboswitches are functional RNA elements that regulate gene expression by directly detecting metabolites. Twenty years have passed since it was first discovered, researches on riboswitches are becoming increasingly standardized and refined, which could significantly promote people's cognition of RNA function as well. Here, we focus on some representative orphan riboswitches, enumerate the structural and functional transformation and artificial design of riboswitches including the coupling with ribozymes, hoping to attain a comprehensive understanding of riboswitch research.
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Affiliation(s)
- Jingdong Xu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin, 300350, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300350, China
| | - Junyuan Hou
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin, 300350, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300350, China
| | - Mengnan Ding
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin, 300350, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300350, China
| | - Zhiwen Wang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin, 300350, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300350, China
| | - Tao Chen
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
- Frontier Science Center for Synthetic Biology, Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin, 300350, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300350, China
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3
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Caulton SG, Lovering AL. Moving toward a better understanding of the model bacterial predator Bdellovibrio bacteriovorus. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001380. [PMID: 37535060 PMCID: PMC10482364 DOI: 10.1099/mic.0.001380] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 07/27/2023] [Indexed: 08/04/2023]
Abstract
The bacterial predator Bdellovibrio bacteriovorus is a model for the wider phenomenon of bacteria:bacteria predation, and the specialization required to achieve a lifestyle dependent on prey consumption. Bdellovibrio bacteriovorus is able to recognize, enter and ultimately consume fellow Gram-negative bacteria, killing these prey from within their periplasmic space, and lysing the host at the end of the cycle. The classic phenotype-driven characterization (and observation of predation) has benefitted from an increased focus on molecular mechanisms and fluorescence microscopy and tomography, revealing new features of several of the lifecycle stages. Herein we summarize a selection of these advances and describe likely areas for exploration that will push the field toward a more complete understanding of this fascinating 'two-cell' system.
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Affiliation(s)
- Simon G. Caulton
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
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4
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Ezzedine JA, Desdevises Y, Jacquet S. Bdellovibrio and like organisms: current understanding and knowledge gaps of the smallest cellular hunters of the microbial world. Crit Rev Microbiol 2021; 48:428-449. [PMID: 34595998 DOI: 10.1080/1040841x.2021.1979464] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Almost sixty years ago, Bdellovibrio and like organisms (BALOs) were discovered as the first obligate bacterial predators of other bacteria known to science. Since then, they were shown to be diverse and ubiquitous in the environment, and to bear astonishing ecological, physiological, and metabolic capabilities. The last decade has seen important strides made in understanding the mechanistic basis of their life cycle, the dynamics of their interactions with prey, along with significant developments towards their use in medicine, agriculture, and industry. This review details these achievements, identify current understanding and knowledge gaps to encourage and guide future BALO research.
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Affiliation(s)
- Jade A Ezzedine
- Université Savoie Mont-Blanc, INRAE, CARRTEL, Thonon-les-Bains, France.,Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRAE, IRIG, Université Grenoble Alpes, Grenoble, France
| | - Yves Desdevises
- CNRS, Biologie Intégrative des Organismes Marins, Observatoire Océanologique, Sorbonne Université, Banyuls-sur-Mer, France
| | - Stéphan Jacquet
- Université Savoie Mont-Blanc, INRAE, CARRTEL, Thonon-les-Bains, France
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5
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Cavallo FM, Jordana L, Friedrich AW, Glasner C, van Dijl JM. Bdellovibrio bacteriovorus: a potential 'living antibiotic' to control bacterial pathogens. Crit Rev Microbiol 2021; 47:630-646. [PMID: 33934682 DOI: 10.1080/1040841x.2021.1908956] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Bdellovibrio bacteriovorus is a small Deltaproteobacterium which, since its discovery, has distinguished itself for the unique ability to prey on other Gram-negative bacteria. The studies on this particular "predatory bacterium", have gained momentum in response to the rising problem of antibiotic resistance, because it could be applied as a potential probiotic and antibiotic agent. Hereby, we present recent advances in the study of B. bacteriovorus, comprehending fundamental aspects of its biology, obligatory intracellular life cycle, predation resistance, and potential applications. Furthermore, we discuss studies that pave the road towards the use of B. bacteriovorus as a "living antibiotic" in human therapy, focussing on its interaction with biofilms, the host immune response, predation susceptibility and in vivo application models. The available data imply that it will be possible to upgrade this predator bacterium from a predominantly academic interest to an instrument that could confront antibiotic resistant infections.
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Affiliation(s)
- Francis M Cavallo
- Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Lorea Jordana
- Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Alexander W Friedrich
- Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Corinna Glasner
- Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jan Maarten van Dijl
- Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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6
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Del Valle I, Fulk EM, Kalvapalle P, Silberg JJ, Masiello CA, Stadler LB. Translating New Synthetic Biology Advances for Biosensing Into the Earth and Environmental Sciences. Front Microbiol 2021; 11:618373. [PMID: 33633695 PMCID: PMC7901896 DOI: 10.3389/fmicb.2020.618373] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/17/2020] [Indexed: 12/26/2022] Open
Abstract
The rapid diversification of synthetic biology tools holds promise in making some classically hard-to-solve environmental problems tractable. Here we review longstanding problems in the Earth and environmental sciences that could be addressed using engineered microbes as micron-scale sensors (biosensors). Biosensors can offer new perspectives on open questions, including understanding microbial behaviors in heterogeneous matrices like soils, sediments, and wastewater systems, tracking cryptic element cycling in the Earth system, and establishing the dynamics of microbe-microbe, microbe-plant, and microbe-material interactions. Before these new tools can reach their potential, however, a suite of biological parts and microbial chassis appropriate for environmental conditions must be developed by the synthetic biology community. This includes diversifying sensing modules to obtain information relevant to environmental questions, creating output signals that allow dynamic reporting from hard-to-image environmental materials, and tuning these sensors so that they reliably function long enough to be useful for environmental studies. Finally, ethical questions related to the use of synthetic biosensors in environmental applications are discussed.
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Affiliation(s)
- Ilenne Del Valle
- Systems, Synthetic, and Physical Biology Graduate Program, Rice University, Houston, TX, United States
| | - Emily M. Fulk
- Systems, Synthetic, and Physical Biology Graduate Program, Rice University, Houston, TX, United States
| | - Prashant Kalvapalle
- Systems, Synthetic, and Physical Biology Graduate Program, Rice University, Houston, TX, United States
| | - Jonathan J. Silberg
- Department of BioSciences, Rice University, Houston, TX, United States
- Department of Bioengineering, Rice University, Houston, TX, United States
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, United States
| | - Caroline A. Masiello
- Department of BioSciences, Rice University, Houston, TX, United States
- Department of Earth, Environmental and Planetary Sciences, Rice University, Houston, TX, United States
- Department of Chemistry, Rice University, Houston, TX, United States
| | - Lauren B. Stadler
- Department of Civil and Environmental Engineering, Rice University, Houston, TX, United States
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7
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Wrist A, Sun W, Summers RM. The Theophylline Aptamer: 25 Years as an Important Tool in Cellular Engineering Research. ACS Synth Biol 2020; 9:682-697. [PMID: 32142605 DOI: 10.1021/acssynbio.9b00475] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The theophylline aptamer was isolated from an oligonucleotide library in 1994. Since that time, the aptamer has found wide utility, particularly in synthetic biology, cellular engineering, and diagnostic applications. The primary application of the theophylline aptamer is in the construction and characterization of synthetic riboswitches for regulation of gene expression. These riboswitches have been used to control cellular motility, regulate carbon metabolism, construct logic gates, screen for mutant enzymes, and control apoptosis. Other applications of the theophylline aptamer in cellular engineering include regulation of RNA interference and genome editing through CRISPR systems. Here we describe the uses of the theophylline aptamer for cellular engineering over the past 25 years. In so doing, we also highlight important synthetic biology applications to control gene expression in a ligand-dependent manner.
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Affiliation(s)
- Alexandra Wrist
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Wanqi Sun
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Ryan M. Summers
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
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8
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Bratanis E, Andersson T, Lood R, Bukowska-Faniband E. Biotechnological Potential of Bdellovibrio and Like Organisms and Their Secreted Enzymes. Front Microbiol 2020; 11:662. [PMID: 32351487 PMCID: PMC7174725 DOI: 10.3389/fmicb.2020.00662] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 03/23/2020] [Indexed: 02/01/2023] Open
Abstract
Bdellovibrio and like organisms (BALOs) are obligate predatory bacteria that selectively prey on a broad range of Gram-negative bacteria, including multidrug-resistant human pathogens. Due to their unique lifestyle, they have been long recognized as a potential therapeutic and biocontrol agent. Research on BALOs has rapidly grown over the recent decade, resulting in many publications concerning molecular details of bacterial predation as well as applications thereof in medicine and biotechnology. This review summarizes the current knowledge on biotechnological potential of obligate predatory bacteria and their secreted enzymes.
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Affiliation(s)
- Eleni Bratanis
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Tilde Andersson
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Rolf Lood
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Ewa Bukowska-Faniband
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
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9
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Nora LC, Westmann CA, Guazzaroni ME, Siddaiah C, Gupta VK, Silva-Rocha R. Recent advances in plasmid-based tools for establishing novel microbial chassis. Biotechnol Adv 2019; 37:107433. [PMID: 31437573 DOI: 10.1016/j.biotechadv.2019.107433] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 07/11/2019] [Accepted: 08/16/2019] [Indexed: 12/28/2022]
Abstract
A key challenge for domesticating alternative cultivable microorganisms with biotechnological potential lies in the development of innovative technologies. Within this framework, a myriad of genetic tools has flourished, allowing the design and manipulation of complex synthetic circuits and genomes to become the general rule in many laboratories rather than the exception. More recently, with the development of novel technologies such as DNA automated synthesis/sequencing and powerful computational tools, molecular biology has entered the synthetic biology era. In the beginning, most of these technologies were established in traditional microbial models (known as chassis in the synthetic biology framework) such as Escherichia coli and Saccharomyces cerevisiae, enabling fast advances in the field and the validation of fundamental proofs of concept. However, it soon became clear that these organisms, although extremely useful for prototyping many genetic tools, were not ideal for a wide range of biotechnological tasks due to intrinsic limitations in their molecular/physiological properties. Over the last decade, researchers have been facing the great challenge of shifting from these model systems to non-conventional chassis with endogenous capacities for dealing with specific tasks. The key to address these issues includes the generation of narrow and broad host plasmid-based molecular tools and the development of novel methods for engineering genomes through homologous recombination systems, CRISPR/Cas9 and other alternative methods. Here, we address the most recent advances in plasmid-based tools for the construction of novel cell factories, including a guide for helping with "build-your-own" microbial host.
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Affiliation(s)
- Luísa Czamanski Nora
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil
| | - Cauã Antunes Westmann
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil
| | - María-Eugenia Guazzaroni
- Faculty of Philosophy, Science and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil
| | | | - Vijai Kumar Gupta
- ERA Chair of Green Chemistry, Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, 12618 Tallinn, Estonia
| | - Rafael Silva-Rocha
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo 14049-900, Brazil.
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10
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Dwidar M, Seike Y, Kobori S, Whitaker C, Matsuura T, Yokobayashi Y. Programmable Artificial Cells Using Histamine-Responsive Synthetic Riboswitch. J Am Chem Soc 2019; 141:11103-11114. [PMID: 31241330 DOI: 10.1021/jacs.9b03300] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Artificial cells that encapsulate DNA-programmable protein expression machinery are emerging as an attractive platform for studying fundamental cellular properties and applications in synthetic biology. However, interfacing these artificial cells with the complex and dynamic chemical environment remains a major and urgent challenge. We demonstrate that the repertoire of molecules that artificial cells respond to can be expanded by synthetic RNA-based gene switches, or riboswitches. We isolated an RNA aptamer that binds histamine with high affinity and specificity and used it to design robust riboswitches that activate protein expression in the presence of histamine. Finally, the riboswitches were incorporated in artificial cells to achieve controlled release of an encapsulated small molecule and to implement a self-destructive kill-switch. Synthetic riboswitches should serve as modular and versatile interfaces to link artificial cell phenotypes with the complex chemical environment.
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Affiliation(s)
- Mohammed Dwidar
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University , Onna , Okinawa 904-0495 , Japan
| | - Yusuke Seike
- Department of Biotechnology, Graduate School of Engineering , Osaka University , 2-1 Yamadaoka , Suita , Osaka 565-0871 , Japan
| | - Shungo Kobori
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University , Onna , Okinawa 904-0495 , Japan
| | - Charles Whitaker
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University , Onna , Okinawa 904-0495 , Japan
| | - Tomoaki Matsuura
- Department of Biotechnology, Graduate School of Engineering , Osaka University , 2-1 Yamadaoka , Suita , Osaka 565-0871 , Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University , Onna , Okinawa 904-0495 , Japan
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11
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Cañadas IC, Groothuis D, Zygouropoulou M, Rodrigues R, Minton NP. RiboCas: A Universal CRISPR-Based Editing Tool for Clostridium. ACS Synth Biol 2019; 8:1379-1390. [PMID: 31181894 DOI: 10.1021/acssynbio.9b00075] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Members of the genus Clostridium represent a diverse assemblage of species exhibiting both medical and industrial importance. Deriving both a greater understanding of their biology, while at the same time enhancing their exploitable properties, requires effective genome editing tools. Here, we demonstrate the first implementation in the genus of theophylline-dependent, synthetic riboswitches exhibiting a full set of dynamic ranges, also suitable for applications where tight control of gene expression is required. Their utility was highlighted by generating a novel riboswitch-based editing tool-RiboCas-that overcomes the main obstacles associated with CRISPR/Cas9 systems, including low transformation efficiencies and excessive Cas9 toxicity. The universal nature of the tool was established by obtaining chromosomal modifications in C. pasteurianum, C. difficile, and C. sporogenes, as well as by carrying out the first reported example of CRISPR-targeted gene disruption in C. botulinum. The high efficiency (100% mutant generation) and ease of application of RiboCas make it suitable for use in a diverse range of microorganisms.
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Affiliation(s)
- Inés C. Cañadas
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham NG7 2RD, U.K
| | - Daphne Groothuis
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham NG7 2RD, U.K
| | - Maria Zygouropoulou
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham NG7 2RD, U.K
| | - Raquel Rodrigues
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham NG7 2RD, U.K
| | - Nigel P. Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham NG7 2RD, U.K
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham NG7 2RD, U.K
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12
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Dwidar M, Yokobayashi Y. Riboswitch Signal Amplification by Controlling Plasmid Copy Number. ACS Synth Biol 2019; 8:245-250. [PMID: 30682247 DOI: 10.1021/acssynbio.8b00454] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Riboswitches are cis-acting RNA devices in mRNAs that control gene expression in response to chemical inputs. As RNA aptamers that recognize diverse classes of molecules can be isolated by in vitro selection, synthetic riboswitches hold promise for various applications in synthetic biology. One of the major drawbacks of riboswitches, however, is their limited dynamic range. A high level of gene expression in the OFF state (leakage) is also a common problem. To address these challenges, we designed and constructed a dual-riboswitch plasmid in which two genes are controlled by theophylline-activated riboswitches. One riboswitch controls the gene of interest, and another riboswitch controls RepL, a phage-derived replication protein that regulates the plasmid copy number. This single-plasmid system afforded an ON/OFF ratio as high as 3900. Furthermore, we used the system to control CRISPR interference (CRISPRi) targeting endogenous genes, and successfully observed expected phenotypic changes in Escherichia coli.
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Affiliation(s)
- Mohammed Dwidar
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495, Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495, Japan
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13
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Abstract
In bacteria and archaea, small RNAs (sRNAs) regulate complex networks through antisense interactions with target mRNAs in trans, and riboswitches regulate gene expression in cis based on the ability to bind small-molecule ligands. Although our understanding and characterization of these two important regulatory RNA classes is far from complete, these RNA-based mechanisms have proven useful for a wide variety of synthetic biology applications. Besides classic and contemporary applications in the realm of metabolic engineering and orthogonal gene control, this review also covers newer applications of regulatory RNAs as biosensors, logic gates, and tools to determine RNA-RNA interactions. A separate section focuses on critical insights gained and challenges posed by fundamental studies of sRNAs and riboswitches that should aid future development of synthetic regulatory RNAs.
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Zhang T, Yang Y, Liang Y, Jiao X, Zhao C. Beneficial Effect of Intestinal Fermentation of Natural Polysaccharides. Nutrients 2018; 10:E1055. [PMID: 30096921 PMCID: PMC6116026 DOI: 10.3390/nu10081055] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 07/27/2018] [Accepted: 08/07/2018] [Indexed: 12/11/2022] Open
Abstract
With the rapid development of modern society, many chronic diseases are increasing including diabetes, obesity, cardiovascular diseases, etc., which further cause an increased death rate worldwide. A high caloric diet with reduced natural polysaccharides, typically indigestible polysaccharides, is considered a health risk factor. With solid evidence accumulating that indigestible polysaccharides can effectively prevent and/or ameliorate symptoms of many chronic diseases, we give a narrative review of many natural polysaccharides extracted from various food resources which mainly contribute their health beneficial functions via intestinal fermentation.
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Affiliation(s)
- Tiehua Zhang
- College of Food Science and Engineering, Jilin University, Changchun 130062, Jilin, China.
| | - Yang Yang
- College of Food Science and Engineering, Jilin University, Changchun 130062, Jilin, China.
| | - Yuan Liang
- College of Food Science and Engineering, Jilin University, Changchun 130062, Jilin, China.
| | - Xu Jiao
- College of Food Science and Engineering, Jilin University, Changchun 130062, Jilin, China.
| | - Changhui Zhao
- College of Food Science and Engineering, Jilin University, Changchun 130062, Jilin, China.
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