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Radford F, Rinehart J, Isaacs FJ. Mapping the in vivo fitness landscape of a tethered ribosome. SCIENCE ADVANCES 2023; 9:eade8934. [PMID: 37115918 PMCID: PMC10146877 DOI: 10.1126/sciadv.ade8934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Fitness landscapes are models of the sequence space of a genetic element that map how each sequence corresponds to its activity and can be used to guide laboratory evolution. The ribosome is a macromolecular machine that is essential for protein synthesis in all organisms. Because of the prevalence of dominant lethal mutations, a comprehensive fitness landscape of the ribosomal peptidyl transfer center (PTC) has not yet been attained. Here, we develop a method to functionally map an orthogonal tethered ribosome (oRiboT), which permits complete mutagenesis of nucleotides located in the PTC and the resulting epistatic interactions. We found that most nucleotides studied showed flexibility to mutation, and identified epistatic interactions between them, which compensate for deleterious mutations. This work provides a basis for a deeper understanding of ribosome function and malleability and could be used to inform design of engineered ribosomes with applications to synthesize next-generation biomaterials and therapeutics.
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Affiliation(s)
- Felix Radford
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA
- Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Jesse Rinehart
- Systems Biology Institute, Yale University, West Haven, CT 06516, USA
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Farren J. Isaacs
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA
- Systems Biology Institute, Yale University, West Haven, CT 06516, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
- Corresponding author.
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Kumar H, Williford EE, Blake KS, Virgin-Downey B, Dantas G, Wencewicz TA, Tolia NH. Structure of anhydrotetracycline-bound Tet(X6) reveals the mechanism for inhibition of type 1 tetracycline destructases. Commun Biol 2023; 6:423. [PMID: 37062778 PMCID: PMC10106456 DOI: 10.1038/s42003-023-04792-4] [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: 07/22/2022] [Accepted: 03/31/2023] [Indexed: 04/18/2023] Open
Abstract
Inactivation of tetracycline antibiotics by tetracycline destructases (TDases) remains a clinical and agricultural threat. TDases can be classified as type 1 Tet(X)-like TDases and type 2 soil-derived TDases. Type 1 TDases are widely identified in clinical pathogens. A combination therapy of tetracycline and a TDase inhibitor is much needed to rescue the clinical efficacy of tetracyclines. Anhydrotetracycline is a pan-TDase inhibitor that inhibits both type 1 and type 2 TDases. Here, we present structural, biochemical, and phenotypic evidence that anhydrotetracycline binds in a substrate-like orientation and competitively inhibits the type 1 TDase Tet(X6) to rescue tetracycline antibiotic activity as a sacrificial substrate. Anhydrotetracycline interacting residues of Tet(X6) are conserved within type 1 TDases, indicating a conserved binding mode and mechanism of inhibition. This mode of binding and inhibition is distinct from anhydrotetracycline's inhibition of type 2 TDases. This study forms the framework for development of next-generation therapies to counteract enzymatic tetracycline resistance.
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Affiliation(s)
- Hirdesh Kumar
- Host-pathogen interaction and structural vaccinology section (HPISV), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Emily E Williford
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO, 63130, USA
| | - Kevin S Blake
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Brett Virgin-Downey
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO, 63130, USA
| | - Gautam Dantas
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA.
| | - Timothy A Wencewicz
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, MO, 63130, USA.
| | - Niraj H Tolia
- Host-pathogen interaction and structural vaccinology section (HPISV), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD, USA.
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53
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Ren H, Lu Z, Sun R, Wang X, Zhong J, Su T, He Q, Liao X, Liu Y, Lian X, Sun J. Functional metagenomics reveals wildlife as natural reservoirs of novel β-lactamases. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 868:161505. [PMID: 36626997 DOI: 10.1016/j.scitotenv.2023.161505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/21/2022] [Accepted: 01/05/2023] [Indexed: 06/17/2023]
Abstract
The antibiotic resistances in bacteria are believed to rapidly evolve over time in the anthropogenic environments which enriched with selection pressures. However, the knowledge regarding the development of antibiotic resistance in wildlife and their habitats is scarce. It is, therefore, of great interest and significance to unveil the yet-unknown antibiotic resistances in wildlife in accordance with One Health concept. To this end, we analyzed the samples taken from wildlife and surrounding environments using a functional metagenomics approach. By functional screening in combination with Illumina sequencing, a total of 32 candidate genes which encoding putative novel β-lactamase were identified. These putative β-lactamase were taxonomically assigned into bacteria of 23 genera from 7 phyla, where Proteobacteria, Actinobacteria and Firmicutes were dominant. The following functional assessment demonstrated that 4 novel β-lactamases, namely blaSSA, blaSSB1, blaSSB2 and blaSSD, were functionally active to confer the phenotypical resistance to bacteria by increasing MICs up to 128-fold. Further analysis indicated that the novel β-lactamases identified in the current study were able to hydrolyze a broad spectrum of β-lactams including cephalosporins, and they were genetically unique comparing with known β-lactamases. The plausible transmission of some novel β-lactamase genes was supported by our results as the same gene was detected in different samples from different sites. This study shed the light on the active role of wildlife and associated environments as natural reservoirs of novel β-lactamases, implying that the antibiotic resistances might evolve in absence of selection pressure and threaten public health once spread into clinically important pathogens.
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Affiliation(s)
- Hao Ren
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Zhaoxiang Lu
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Ruanyang Sun
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Xiran Wang
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Jiahao Zhong
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Tiantian Su
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Qian He
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Xiaoping Liao
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Yahong Liu
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Xinlei Lian
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Jian Sun
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou University, Yangzhou 225009, China.
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Yu Y, Gong B, Wang H, Yang G, Zhou X. Chromosome evolution of Escherichia coli Nissle 1917 for high-level production of heparosan. Biotechnol Bioeng 2023; 120:1081-1096. [PMID: 36539926 DOI: 10.1002/bit.28315] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 12/11/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022]
Abstract
Heparosan is a crucial-polysaccharide precursor for the chemoenzymatic synthesis of heparin, a widely used anticoagulant drug. Presently, heparosan is mainly extracted with the potential risk of contamination from Escherichia coli strain K5, a pathogenic bacterium causing urinary tract infection. Here, a nonpathogenic probiotic, E. coli strain Nissle 1917 (EcN), was metabolically engineered to carry multiple copies of the 19-kb kps locus and produce heparosan to 9.1 g/L in fed-batch fermentation. Chromosome evolution driven by antibiotics was employed to amplify the kps locus, which governed the synthesis and export of heparosan from EcN at 21 mg L-1 OD-1 . The average copy number of kps locus increased from 1 to 24 copies per cell, which produced up to 104 mg L-1 OD-1 of heparosan in the shaking flask cultures of engineered strains. The following in-frame deletion of recA stabilized the recombinant duplicates of chromosomal kps locus and the productivity of heparosan in continuous culture for at least 56 generations. Fed-batch fermentation of the engineered strain EcN8 was carried out to bring the yield of heparosan up to 9.1 g/L. Heparosan from the fermentation culture was further purified at a 75% overall recovery. The structure of purified heparosan was characterized and further modified by N-sulfotransferase with 3'-phosphoadenosine-5'-phosphosulfate as the sulfo-donor. The analysis of element composition showed that heparosan was N-sulfated by over 80%. These results indicated that duplicating large DNA cassettes up to 19-kb, followed by high-cell-density fermentation, was promising in the large-scale preparation of chemicals and could be adapted to engineer other industrial-interest bacteria metabolically.
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Affiliation(s)
- Yanying Yu
- Department of Bioengineering, School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, China
| | - Bingxue Gong
- Department of Bioengineering, School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, China
| | - Huili Wang
- Department of Bioengineering, School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, China
| | - Guixia Yang
- Department of Bioengineering, School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, China
| | - Xianxuan Zhou
- Department of Bioengineering, School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, China
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Jiang H, Jiao X, Yu T, Wang W, Cheng H, Huang G, Fang J. Contribution of different class 2 integron elements to fitness costs in multi-drug resistant Escherichia coli and evaluation of their adaptability in “farm-to-table” environments. Food Microbiol 2023; 113:104279. [PMID: 37098435 DOI: 10.1016/j.fm.2023.104279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 03/13/2023] [Accepted: 04/03/2023] [Indexed: 04/08/2023]
Abstract
Integrons play a pivotal role in the dissemination of antimicrobial resistance, because they can capture and express exogenous antimicrobial resistance genes. This study aimed to elucidate the structure and contribution of different elements of class 2 integrons to fitness costs in their host bacteria and evaluate their adaptability to the "farm-to-table" process. We mapped 27 typical class 2 integrons of Escherichia coli isolated from aquatic foods and pork products, each harboring an inactive truncated class 2 integrase gene and the gene cassette (GC) array dfrA1-sat2-aadA1 with strong Pc2A/Pc2B promoters. Notably, the fitness costs associated with class 2 integrons depended on the Pc promoter strength and quantity and content of GCs in the array. Additionally, the costs of integrases were activity-dependent, and a balance was identified between GC capture ability and integron stability, which could explain the inactive truncated integrase identified. Although typical class 2 integrons exhibited low-cost structures in E. coli, the bacteria incurred biological costs, including decreasing growth rates and biofilm formation, in farm-to-table environments, especially under low-nutrient conditions. Nevertheless, sub-inhibitory antibiotic concentrations led to the selection of class 2 integron-carrying bacteria. This study provides important insights into how integrons may travel from preharvest to consumer goods.
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56
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Zhou GJ, Zhang F. Applications and Tuning Strategies for Transcription Factor-Based Metabolite Biosensors. BIOSENSORS 2023; 13:428. [PMID: 37185503 PMCID: PMC10136082 DOI: 10.3390/bios13040428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 05/17/2023]
Abstract
Transcription factor (TF)-based biosensors are widely used for the detection of metabolites and the regulation of cellular pathways in response to metabolites. Several challenges hinder the direct application of TF-based sensors to new hosts or metabolic pathways, which often requires extensive tuning to achieve the optimal performance. These tuning strategies can involve transcriptional or translational control depending on the parameter of interest. In this review, we highlight recent strategies for engineering TF-based biosensors to obtain the desired performance and discuss additional design considerations that may influence a biosensor's performance. We also examine applications of these sensors and suggest important areas for further work to continue the advancement of small-molecule biosensors.
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Affiliation(s)
- Gloria J. Zhou
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA;
| | - Fuzhong Zhang
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA;
- Division of Biology & Biomedical Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA
- Institute of Materials Science & Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
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English MA, Alcantar MA, Collins JJ. A self‐propagating, barcoded transposon system for the dynamic rewiring of genomic networks. Mol Syst Biol 2023:e11398. [DOI: 10.15252/msb.202211398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 03/08/2023] [Accepted: 03/10/2023] [Indexed: 03/29/2023] Open
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Park JH, Bassalo MC, Lin GM, Chen Y, Doosthosseini H, Schmitz J, Roubos JA, Voigt CA. Design of Four Small-Molecule-Inducible Systems in the Yeast Chromosome, Applied to Optimize Terpene Biosynthesis. ACS Synth Biol 2023; 12:1119-1132. [PMID: 36943773 PMCID: PMC10127285 DOI: 10.1021/acssynbio.2c00607] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
The optimization of cellular functions often requires the balancing of gene expression, but the physical construction and screening of alternative designs are costly and time-consuming. Here, we construct a strain of Saccharomyces cerevisiae that contains a "sensor array" containing bacterial regulators that respond to four small-molecule inducers (vanillic acid, xylose, aTc, IPTG). Four promoters can be independently controlled with low background and a 40- to 5000-fold dynamic range. These systems can be used to study the impact of changing the level and timing of gene expression without requiring the construction of multiple strains. We apply this approach to the optimization of a four-gene heterologous pathway to the terpene linalool, which is a flavor and precursor to energetic materials. Using this approach, we identify bottlenecks in the metabolic pathway. This work can aid the rapid automated strain development of yeasts for the bio-manufacturing of diverse products, including chemicals, materials, fuels, and food ingredients.
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Affiliation(s)
- Jong Hyun Park
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, 500 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Marcelo C Bassalo
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, 500 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Geng-Min Lin
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, 500 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Ye Chen
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, 500 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Hamid Doosthosseini
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, 500 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Joep Schmitz
- DSM Science & Innovation, Biodata & Translational Sciences, P.O. Box 1, 2600 MA Delft, The Netherlands
| | - Johannes A Roubos
- DSM Science & Innovation, Biodata & Translational Sciences, P.O. Box 1, 2600 MA Delft, The Netherlands
| | - Christopher A Voigt
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, 500 Technology Square, Cambridge, Massachusetts 02139, United States
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Cheng YY, Zhou Z, Papadopoulos JM, Zuke JD, Falbel TG, Anantharaman K, Burton BM, Venturelli OS. Efficient plasmid transfer via natural competence in a microbial co-culture. Mol Syst Biol 2023; 19:e11406. [PMID: 36714980 PMCID: PMC9996237 DOI: 10.15252/msb.202211406] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/21/2022] [Accepted: 01/09/2023] [Indexed: 01/31/2023] Open
Abstract
The molecular and ecological factors shaping horizontal gene transfer (HGT) via natural transformation in microbial communities are largely unknown, which is critical for understanding the emergence of antibiotic-resistant pathogens. We investigate key factors shaping HGT in a microbial co-culture by quantifying extracellular DNA release, species growth, and HGT efficiency over time. In the co-culture, plasmid release and HGT efficiency are significantly enhanced than in the respective monocultures. The donor is a key determinant of HGT efficiency as plasmids induce the SOS response, enter a multimerized state, and are released in high concentrations, enabling efficient HGT. However, HGT is reduced in response to high donor lysis rates. HGT is independent of the donor viability state as both live and dead cells transfer the plasmid with high efficiency. In sum, plasmid HGT via natural transformation depends on the interplay of plasmid properties, donor stress responses and lysis rates, and interspecies interactions.
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Affiliation(s)
- Yu-Yu Cheng
- Department of Biochemistry, University of Wisconsin, Madison, WI, USA
| | - Zhichao Zhou
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | - James M Papadopoulos
- Department of Chemical & Biological Engineering, University of Wisconsin, Madison, WI, USA
| | - Jason D Zuke
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Tanya G Falbel
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | | | - Briana M Burton
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Ophelia S Venturelli
- Department of Biochemistry, University of Wisconsin, Madison, WI, USA.,Department of Bacteriology, University of Wisconsin, Madison, WI, USA.,Department of Chemical & Biological Engineering, University of Wisconsin, Madison, WI, USA
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Tomoyasu T, Matsumoto A, Takao A, Tabata A, Nagamune H. A simple method to differentiate three classes of cholesterol-dependent cytolysins. J Microbiol Methods 2023; 207:106696. [PMID: 36898586 DOI: 10.1016/j.mimet.2023.106696] [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: 01/05/2023] [Revised: 03/06/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023]
Abstract
Cholesterol-dependent cytolysins (CDCs) are proteinaceous toxins widely distributed in gram-positive pathogenic bacteria. CDCs can be classified into three groups (I-III) based on the mode of receptor recognition. Group I CDCs recognize cholesterol as their receptor. Group II CDC specifically recognizes human CD59 as the primary receptor on the cell membrane. Only intermedilysin from Streptococcus intermedius has been reported as a group II CDC. Group III CDCs recognize both human CD59 and cholesterol as receptors. CD59 contains five disulfide bridges in its tertiary structure. Therefore, we treated human erythrocytes with dithiothreitol (DTT) to inactivate CD59 on membranes. Our data showed that DTT treatment caused a complete loss of recognition of intermedilysin and an anti-human CD59 monoclonal antibody. In contrast, this treatment did not affect the recognition of group I CDCs, judging from the fact that DTT-treated erythrocytes were lysed with the same efficiency as mock-treated human erythrocytes. The recognition of group III CDCs toward DTT-treated erythrocytes was partially reduced, and these results are likely due to the loss of human CD59 recognition. Therefore, the degree of human CD59 and cholesterol requirements of uncharacterized group III CDCs frequently found in Mitis group streptococci can be easily estimated by comparing the amounts of hemolysis between DTT-treated and mock-treated erythrocytes.
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Affiliation(s)
- Toshifumi Tomoyasu
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, Tokushima, Japan; Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan
| | - Airi Matsumoto
- Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan
| | - Ayuko Takao
- Department of Oral Microbiology, School of Dental Medicine, Tsurumi University, Yokohama, Kanagawa, Japan
| | - Atsushi Tabata
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, Tokushima, Japan; Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan
| | - Hideaki Nagamune
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, Tokushima, Japan; Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan.
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61
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Zeng X, Hinenoya A, Guan Z, Xu F, Lin J. Critical role of the RpoE stress response pathway in polymyxin resistance of Escherichia coli. J Antimicrob Chemother 2023; 78:732-746. [PMID: 36658759 PMCID: PMC10396327 DOI: 10.1093/jac/dkad003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/31/2022] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVES Polymyxins, including colistin, are the drugs of last resort to treat MDR bacterial infections in humans. In-depth understanding of the molecular basis and regulation of polymyxin resistance would provide new therapeutic opportunities to combat increasing polymyxin resistance. Here we aimed to identify novel targets that are crucial for polymyxin resistance using Escherichia coli BL21(DE3), a unique colistin-resistant model strain. METHODS BL21(DE3) was subjected to random transposon mutagenesis for screening colistin-susceptible mutants. The insertion sites of desired mutants were mapped; the key genes of interest were also inactivated in different strains to examine functional conservation. Specific genes in the known PmrAB and PhoPQ regulatory network were inactivated to examine crosstalk among different pathways. Lipid A species and membrane phospholipids were analysed by normal phase LC/MS. RESULTS Among eight mutants with increased susceptibility to colistin, five mutants contained different mutations in three genes (rseP, degS and surA) that belong to the RpoE stress response pathway. Inactivation of rpoE, pmrB, eptA or pmrD led to significantly increased susceptibility to colistin; however, inactivation of phoQ or eptB did not change colistin MIC. RpoE mutation in different E. coli and Salmonella resistant strains all led to significant reduction in colistin MIC (16-32-fold). Inactivation of rpoE did not change the lipid A profile but significantly altered the phospholipid profile. CONCLUSIONS Inactivation of the important members of the RpoE regulon in polymyxin-resistant strains led to a drastic reduction in polymyxin MIC and an increase of lysophospholipids with no change in lipid A modifications.
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Affiliation(s)
- Ximin Zeng
- Department of Animal Science, The University of Tennessee, Knoxville, TN, USA
| | - Atsushi Hinenoya
- Department of Animal Science, The University of Tennessee, Knoxville, TN, USA
- Graduate School of Veterinary Science, Osaka Metropolitan University, Osaka, Japan
- Asian Health Science Research Institute, Osaka Metropolitan University, Osaka, Japan
- Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan
| | - Ziqiang Guan
- Department of Biochemistry, Duke University Medical Center, Durham, NC, USA
| | - Fuzhou Xu
- Department of Animal Science, The University of Tennessee, Knoxville, TN, USA
- Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Jun Lin
- Department of Animal Science, The University of Tennessee, Knoxville, TN, USA
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Zhu Y, Gao H, Zhang J, Zhao J, Qi Q, Wang Q. De novo design of the global transcriptional factor Cra-regulated promoters enables highly sensitive glycolysis flux biosensor for dynamic metabolic control. Microb Biotechnol 2023; 16:605-617. [PMID: 36541030 PMCID: PMC9948231 DOI: 10.1111/1751-7915.14166] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 10/09/2022] [Accepted: 10/19/2022] [Indexed: 12/24/2022] Open
Abstract
Glycolytic flux is a fundamental index in microbial cell factories. A glycolytic flux biosensor that can monitor glucose metabolism efficiency is a promising strategy in rewiring metabolic flux to balance growth and biosynthesis. A key design feature of the glycolytic flux biosensors is the interaction between the global transcriptional factor Cra and its regulated promoters. However, overexpression and mutation of Cra has unpredictable effects on global metabolism in Escherichia coli. Therefore, new orthogonal biosensor design strategies should be developed to circumvent metabolic issues. In this report, the promoters in glycolytic flux biosensor were replaced with synthetic promoters of varying strengths or phage-derived promoters, and the Cra DNA-binding sites were deployed into promoters at different positions and distances to yield biosensors. The de nova biosensors that depended on Cra could sense Fructose-1,6-diphosphate (FBP) with broad dynamic ranges and low basal leakage. Then the negative-response biosensors were applied to fine-tune the target ATP synthesis gene, leading to the desired increase in pyruvate production (the highest 9.66 g/L) and cell growth. Moreover, the membrane synthesis gene plsC was also dynamically activated by the positive-response biosensor, leading to effective accumulation of lycopene in the cell membrane and a 50-fold increase in lycopene titre (100.3 mg/L) when compared with the control strain, demonstrating the effective and broader usages of our biosensors.
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Affiliation(s)
- Yuan Zhu
- National Glycoengineering Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Huaxiao Gao
- National Glycoengineering Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Jian Zhang
- National Glycoengineering Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Jingyu Zhao
- National Glycoengineering Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Qingsheng Qi
- National Glycoengineering Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Qian Wang
- National Glycoengineering Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
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63
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Wagner N, Bade F, Straube E, Rabe K, Frazão CJR, Walther T. In vivo implementation of a synthetic metabolic pathway for the carbon-conserving conversion of glycolaldehyde to acetyl-CoA. Front Bioeng Biotechnol 2023; 11:1125544. [PMID: 36845174 PMCID: PMC9947464 DOI: 10.3389/fbioe.2023.1125544] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 01/30/2023] [Indexed: 02/11/2023] Open
Abstract
Ethylene glycol (EG) derived from plastic waste or CO2 can serve as a substrate for microbial production of value-added chemicals. Assimilation of EG proceeds though the characteristic intermediate glycolaldehyde (GA). However, natural metabolic pathways for GA assimilation have low carbon efficiency when producing the metabolic precursor acetyl-CoA. In alternative, the reaction sequence catalyzed by EG dehydrogenase, d-arabinose 5-phosphate aldolase, d-arabinose 5-phosphate isomerase, d-ribulose 5-phosphate 3-epimerase (Rpe), d-xylulose 5-phosphate phosphoketolase, and phosphate acetyltransferase may enable the conversion of EG into acetyl-CoA without carbon loss. We investigated the metabolic requirements for in vivo function of this pathway in Escherichia coli by (over)expressing constituting enzymes in different combinations. Using 13C-tracer experiments, we first examined the conversion of EG to acetate via the synthetic reaction sequence and showed that, in addition to heterologous phosphoketolase, overexpression of all native enzymes except Rpe was required for the pathway to function. Since acetyl-CoA could not be reliably quantified by our LC/MS-method, the distribution of isotopologues in mevalonate, a stable metabolite that is exclusively derived from this intermediate, was used to probe the contribution of the synthetic pathway to biosynthesis of acetyl-CoA. We detected strong incorporation of 13C carbon derived from labeled GA in all intermediates of the synthetic pathway. In presence of unlabeled co-substrate glycerol, 12.4% of the mevalonate (and therefore acetyl-CoA) was derived from GA. The contribution of the synthetic pathway to acetyl-CoA production was further increased to 16.1% by the additional expression of the native phosphate acyltransferase enzyme. Finally, we demonstrated that conversion of EG to mevalonate was feasible albeit at currently extremely small yields.
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Affiliation(s)
- Nils Wagner
- TU Dresden, Institute of Natural Materials Technology, Dresden, Germany
| | - Frederik Bade
- TU Dresden, Institute of Natural Materials Technology, Dresden, Germany
| | - Elly Straube
- TU Dresden, Institute of Natural Materials Technology, Dresden, Germany
| | - Kenny Rabe
- TU Dresden, Institute of Natural Materials Technology, Dresden, Germany
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64
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Carrillo Rincón AF, Farny NG. Unlocking the strength of inducible promoters in Gram-negative bacteria. Microb Biotechnol 2023; 16:961-976. [PMID: 36738130 PMCID: PMC10128130 DOI: 10.1111/1751-7915.14219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 01/02/2023] [Accepted: 01/07/2023] [Indexed: 02/05/2023] Open
Abstract
Inducible bacterial promoters are ubiquitous biotechnology tools that have a consistent architecture including two key elements: the operator region recognized by the transcriptional regulatory proteins, and the -10 and -35 consensus sequences required to recruit the sigma (σ) 70 subunits of RNA polymerase to initiate transcription. Despite their widespread use, leaky transcription in the OFF state remains a challenge. We have updated the architecture of the lac and tet promoters to improve their strength, control and portability by the adaptation of the consensus -10 and -35 sequence boxes strongly targeted by σ70 , incorporation of a strong ribosome binding site recognized broadly by Gram-negative bacteria, and independent control of the transcriptional regulators by constitutive promoters. To test the promoters, we use the far-red fluorescent protein mCardinal, which significantly improves the signal-to-background ratio of promoter measurements over widely utilized green fluorescent proteins. We validate the improvement in OFF state control and inducibility by demonstrating production of the toxic and aggregate-prone cocaine esterase enzyme CocE. We further demonstrate portability of the promoters to additional Gram-negative species Pseudomonas putida and Vibrio natriegens. Our results represent a significant improvement over existing protein expression systems that will enable advances in protein production for various biotechnology applications.
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Affiliation(s)
| | - Natalie G Farny
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
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65
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Brawley H, Kreinbrink AC, Hierholzer JD, Vali SW, Lindahl PA. Labile Iron Pool of Isolated Escherichia coli Cytosol Likely Includes Fe-ATP and Fe-Citrate but not Fe-Glutathione or Aqueous Fe. J Am Chem Soc 2023; 145:2104-2117. [PMID: 36661842 PMCID: PMC9896560 DOI: 10.1021/jacs.2c06625] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Indexed: 01/21/2023]
Abstract
The existence of labile iron pools (LFePs) in biological systems has been recognized for decades, but their chemical composition remains uncertain. Here, the LFeP in cytosol from Escherichia coli was investigated. Mössbauer spectra of whole vs lysed cells indicated significant degradation of iron-sulfur clusters (ISCs), even using an unusually gentle lysis procedure; this demonstrated the fragility of ISCs. Moreover, the released iron contributed to the non-heme high-spin Fe(II) species in the cell, which likely included the LFeP. Cytosol batches isolated from cells grown with different levels of iron supplementation were passed through a 3 kDa cutoff membrane, and resulting flow-through-solutions (FTSs) were subjected to SEC-ICP-MS. Mössbauer spectroscopy was used to evaluate the oxidation states of standards. FTSs exhibited iron-detected peaks likely due to different forms of Fe-citrate and Fe-nucleotide triphosphate complexes. Fe-Glutathione (GSH) complexes were not detected using physiological concentrations of GSH mixed with either Fe(II) or Fe(III); Fe(II)-GSH was concluded not to be a significant component of the LFeP in E. coli under physiological conditions. Aqueous iron was also not present in significant concentrations in isolated cytosol and is unlikely a major component of the pool. Fe appeared to bind ATP more tightly than citrate, but ATP also hydrolyzed on the timescale of tens of hours. Isolated cytosol contained excess ligands that coordinated the added Fe(II) and Fe(III). The LFeP in healthy metabolically active cells is undoubtedly dominated by the Fe(II) state, but the LFeP is redox-active such that a fraction might be present as stable and soluble Fe(III) complexes especially under oxidatively stressed cellular conditions.
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Affiliation(s)
- Hayley
N. Brawley
- Department
of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
| | - Alexia C. Kreinbrink
- Department
of Biochemistry and Biophysics, Texas A&M
University, College
Station, Texas 77843, United States
| | - Justin D. Hierholzer
- Department
of Biochemistry and Biophysics, Texas A&M
University, College
Station, Texas 77843, United States
| | - Shaik Waseem Vali
- Department
of Biochemistry and Biophysics, Texas A&M
University, College
Station, Texas 77843, United States
| | - Paul A. Lindahl
- Department
of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
- Department
of Biochemistry and Biophysics, Texas A&M
University, College
Station, Texas 77843, United States
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66
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An N, Xie C, Zhou S, Wang J, Sun X, Yan Y, Shen X, Yuan Q. Establishing a growth-coupled mechanism for high-yield production of β-arbutin from glycerol in Escherichia coli. BIORESOURCE TECHNOLOGY 2023; 369:128491. [PMID: 36529444 DOI: 10.1016/j.biortech.2022.128491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 12/10/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Biodiesel production has increased significantly in recent years, leading to an increase in the production of crude glycerol. In this study, a novel growth-coupled erythrose 4-phosphate (E4P) formation strategy that can be used to produce high levels of β-arbutin using engineered Escherichia coli and glycerol as the carbon source was developed. In the strategy, E4P formation was coupled with cell growth, and a growth-driving force made the E4P formation efficient. By applying this strategy, efficient microbial synthesis of β-arbutin was achieved, with 7.91 g/L β-arbutin produced in shaking flask, and 28.1 g/L produced in a fed batch fermentation with a yield of 0.20 g/g glycerol and a productivity of 0.39 g/L/h. This is the highest β-arbutin production through microbial fermentation ever reported to date. This study may have significant implications in the large-scale production of β-arbutin as well as other aromatic compounds of importance.
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Affiliation(s)
- Ning An
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Chong Xie
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Shubin Zhou
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jia Wang
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Xinxiao Sun
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Yajun Yan
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA 30602, USA
| | - Xiaolin Shen
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Qipeng Yuan
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
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67
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Binelli MR, Kan A, Rozas LEA, Pisaturo G, Prakash N, Studart AR. Complex Living Materials Made by Light-Based Printing of Genetically Programmed Bacteria. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2207483. [PMID: 36444840 DOI: 10.1002/adma.202207483] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 11/23/2022] [Indexed: 06/16/2023]
Abstract
Living materials with embedded microorganisms can genetically encode attractive sensing, self-repairing, and responsive functionalities for applications in medicine, robotics, and infrastructure. While the synthetic toolbox for genetically engineering bacteria continues to expand, technologies to shape bacteria-laden living materials into complex 3D geometries are still rather limited. Here, it is shown that bacteria-laden hydrogels can be shaped into living materials with unusual architectures and functionalities using readily available light-based printing techniques. Bioluminescent and melanin-producing bacteria are used to create complex materials with autonomous chemical-sensing capabilities by harnessing the metabolic activity of wild-type and engineered microorganisms. The shaping freedom offered by printing technologies and the rich biochemical diversity available in bacteria provides ample design space for the creation and exploration of complex living materials with programmable functionalities for a broad range of applications.
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Affiliation(s)
- Marco R Binelli
- Complex Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
| | - Anton Kan
- Complex Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
| | - Luis E A Rozas
- Complex Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
| | - Giovanni Pisaturo
- Complex Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
| | - Namita Prakash
- Complex Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
| | - André R Studart
- Complex Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, Zürich, 8093, Switzerland
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68
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Srivastava R, Bagh S. A Logically Reversible Double Feynman Gate with Molecular Engineered Bacteria Arranged in an Artificial Neural Network-Type Architecture. ACS Synth Biol 2023; 12:51-60. [PMID: 36384003 DOI: 10.1021/acssynbio.2c00520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Reversible logic gates are the key components of reversible computing that map inputs and outputs in a certain one-to-one pattern so that the output signals can reveal the pattern of the input signals. One of the main research foci of reversible computing is the implementation of basic reversible gates by various modalities. Though true thermodynamic reversibility cannot be attained within living cells, the high energy efficiency of biological reactions inspires the implementation of reversible computation in living cells. The implementation of synthetic genetic circuits is mostly based on conventional irreversible computing, and the implementation of logical reversibility in living cells is rare. Here, we constructed a 3-input-3-output synthetic genetic reversible double Feynman logic gate with a population of genetically engineered E. coli cells. Instead of following hierarchical electronic design principles, we adapted the concept of artificial neural networks (ANN) and built a single-layer artificial network-type architecture with five different engineered bacteria, named bactoneurons. We used three extracellular chemicals as input signals and the expression of three fluorescence proteins as the output signals. The cellular devices, which combine the input chemical signals linearly and pass them through a nonlinear activation function and represent specific bactoneurons, were built by designing and creating small synthetic genetic networks inside E. coli. The weights of each of the inputs and biases of individual bactoneurons in the bacterial ANN were adjusted by optimizing the synthetic genetic networks. When arranging the five bactoneurons through an ANN-type architecture, the system generated a double Feynman gate function at the population level. To our knowledge, this is the first reversible double Feynman gate realization with living cells. This work may have significance in development of biocomputer technology, reversible computation, ANN wetware, and synthetic biology.
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Affiliation(s)
- Rajkamal Srivastava
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Block A/F, Sector-I, Bidhannagar, Kolkata700064, India.,Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai400094, India
| | - Sangram Bagh
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Block A/F, Sector-I, Bidhannagar, Kolkata700064, India.,Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai400094, India
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69
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Winckler LI, Dissmeyer N. TEV protease cleavage in generation of artificial substrate proteins bearing neo-N-termini. Methods Enzymol 2023. [PMID: 37532397 DOI: 10.1016/bs.mie.2023.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
Abstract
The tobacco etch virus (TEV) protease is widely used in in vitro and in vivo approaches for the removal of affinity tags from fusion proteins or the generation of proteins with a desired N-terminal amino acid. Processing of fusion proteins by the TEV protease can either be achieved by encoding the TEV protease and its recognition site on one construct (self-cleavage) or on two different constructs (co-expression). Here, we compare the efficiency of the self-splitting approach to the co-expression approach.
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70
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Wang J, Li C, Jiang T, Yan Y. Biosensor-assisted titratable CRISPRi high-throughput (BATCH) screening for over-production phenotypes. Metab Eng 2023; 75:58-67. [PMID: 36375746 PMCID: PMC9845192 DOI: 10.1016/j.ymben.2022.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 11/02/2022] [Accepted: 11/09/2022] [Indexed: 11/13/2022]
Abstract
With rapid advances in the development of metabolic pathways and synthetic biology toolkits, a persisting challenge in microbial bioproduction is how to optimally rewire metabolic fluxes and accelerate the concomitant high-throughput phenotype screening. Here we developed a biosensor-assisted titratable CRISPRi high-throughput (BATCH) screening approach that combines a titratable mismatch CRISPR interference and a biosensor mediated screening for high-production phenotypes in Escherichia coli. We first developed a programmable mismatch CRISPRi that could afford multiple levels of interference efficacy with a one-pot sgRNA pool (a total of 16 variants for each target gene) harboring two consecutive random mismatches in the seed region of sgRNA spacers. The mismatch CRISPRi was demonstrated to enable almost a full range of gene knockdown when targeting different positions on genes. As a proof-of-principle demonstration of the BATCH screening system, we designed doubly mismatched sgRNA pools targeting 20 relevant genes in E. coli and optimized a PadR-based p-coumaric acid biosensor with broad dynamic range for the eGFP fluorescence guided high-production screening. Using sgRNA variants for the combinatorial knockdown of pfkA and ptsI, the p-coumaric acid titer was increased by 40.6% to o 1308.6 mg/l from glycerol in shake flasks. To further demonstrate the general applicability of the BATCH screening system, we recruited a HpdR-based butyrate biosensor that facilitated the screening of E. coli strains achieving 19.0% and 25.2% increase of butyrate titer in shake flasks with sgRNA variants targeting sucA and ldhA, respectively. This work reported the establishment of a plug-and-play approach that enables multilevel modulation of metabolic fluxes and high-throughput screening of high-production phenotypes.
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Affiliation(s)
- Jian Wang
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA, 30602, USA
| | - Chenyi Li
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA, 30602, USA
| | - Tian Jiang
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA, 30602, USA
| | - Yajun Yan
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA, 30602, USA.
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71
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Mahmud B, Boolchandani M, Patel S, Dantas G. Functional Metagenomics to Study Antibiotic Resistance. Methods Mol Biol 2023; 2601:379-401. [PMID: 36445596 DOI: 10.1007/978-1-0716-2855-3_21] [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] [Indexed: 06/16/2023]
Abstract
The construction and screening of metagenomic expression libraries have a great potential to identify novel genes with desired functions. Here, we describe metagenomic library preparation from fecal DNA, screening of libraries for antibiotic resistance genes (ARGs), massively parallel DNA sequencing of the enriched DNA fragments, and a computational pipeline for high-throughput assembly and annotation of functionally selected DNA.
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Affiliation(s)
- Bejan Mahmud
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Manish Boolchandani
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Sanket Patel
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Gautam Dantas
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA.
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72
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Abstract
Gene-by-environment interactions play a crucial role in horizontal gene transfer by affecting how the transferred genes alter host fitness. However, how the environment modulates the fitness effect of transferred genes has not been tested systematically in an experimental study. We adapted a high-throughput technique for obtaining very precise estimates of bacterial fitness, in order to measure the fitness effects of 44 orthologs transferred from Salmonella Typhimurium to Escherichia coli in six physiologically relevant environments. We found that the fitness effects of individual genes were highly dependent on the environment, while the distributions of fitness effects across genes were not, with all tested environments resulting in distributions of same shape and spread. Furthermore, the extent to which the fitness effects of a gene varied between environments depended on the average fitness effect of that gene across all environments, with nearly neutral and nearly lethal genes having more consistent fitness effects across all environments compared to deleterious genes. Put together, our results reveal the unpredictable nature of how environmental conditions impact the fitness effects of each individual gene. At the same time, distributions of fitness effects across environments exhibit consistent features, pointing to the generalizability of factors that shape horizontal gene transfer of orthologous genes.
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Affiliation(s)
- Hande Acar Kirit
- Veterinary and Ecological Sciences, Institute of Infection, University of Liverpool, Liverpool, Merseyside, United Kingdom
- Laboratories of Molecular Anthropology and Microbiome Research, University of Oklahoma, Norman, OK
- Department of Anthropology, University of Oklahoma, Norman, OK
| | - Jonathan P Bollback
- Veterinary and Ecological Sciences, Institute of Infection, University of Liverpool, Liverpool, Merseyside, United Kingdom
| | - Mato Lagator
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
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73
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Jing Kay Lam K, Zhang Z, Saier Jr MH. Histone-like Nucleoid Structuring (H-NS) Protein Silences the beta-glucoside (bgl) Utilization Operon in Escherichia coli by Forming a DNA Loop. Comput Struct Biotechnol J 2022; 20:6287-6301. [DOI: 10.1016/j.csbj.2022.11.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/10/2022] [Accepted: 11/10/2022] [Indexed: 11/15/2022] Open
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74
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Jiang T, Li C, Zou Y, Zhang J, Gan Q, Yan Y. Establishing an Autonomous Cascaded Artificial Dynamic (AutoCAD) regulation system for improved pathway performance. Metab Eng 2022; 74:1-10. [PMID: 36041638 PMCID: PMC10947494 DOI: 10.1016/j.ymben.2022.08.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 07/21/2022] [Accepted: 08/23/2022] [Indexed: 11/17/2022]
Abstract
Endogenous metabolic pathways in microbial cells are usually precisely controlled by sophisticated regulation networks. However, the lack of such regulations when introducing heterologous pathways in microbial hosts often causes unbalanced enzyme expression and carbon flux distribution, hindering the construction of highly efficient microbial biosynthesis systems. Here, using naringenin as the target compound, we developed an Autonomous Cascaded Artificial Dynamic (AutoCAD) regulation system to automatically coordinate the pathway expression and redirect carbon fluxes for enhanced naringenin production. The AutoCAD regulation system, consisting of both intermediate-based feedforward and product-based feedback control genetic circuits, resulted in a 16.5-fold increase in naringenin titer compared with the static control. Fed-batch fermentation using the strain with AutoCAD regulation further enhanced the naringenin titer to 277.2 mg/L. The AutoCAD regulation system, with intermediate-based feedforward control and product-triggered feedback control, provides a new paradigm of developing complicated cascade dynamic control to engineer heterologous pathways.
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Affiliation(s)
- Tian Jiang
- School of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA, 30602, USA
| | - Chenyi Li
- School of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA, 30602, USA
| | - Yusong Zou
- School of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA, 30602, USA
| | - Jianli Zhang
- School of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA, 30602, USA
| | - Qi Gan
- School of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA, 30602, USA
| | - Yajun Yan
- School of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA, 30602, USA.
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75
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VanArsdale E, Pitzer J, Wang S, Stephens K, Chen CY, Payne GF, Bentley WE. Enhanced electrochemical measurement of β-galactosidase activity in whole cells by coexpression of lactose permease, LacY. Biotechniques 2022; 73:233-237. [DOI: 10.2144/btn-2022-0090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Whole-cell biosensing links the sensing and computing capabilities of microbes to the generation of a detectable reporter. Whole cells enable dynamic biological computation (filtered noise, amplified signals, logic gating etc.). Enzymatic reporters enable in situ signal amplification. Electrochemical measurements are easily quantified and work in turbid environments. In this work we show how the coexpression of the lactose permease, LacY, dramatically improves electrochemical sensing of β-galactosidase (LacZ) expressed as a reporter in whole cells. The permease facilitates transport of the LacZ substrate, 4-aminophenyl β-d-galactopyranoside, which is converted to redox active p-aminophenol, which, in turn, is detected via cyclic voltammetry or chronocoulometry. We show a greater than fourfold improvement enabled by lacY coexpression in cells engineered to respond to bacterial signal molecules, pyocyanin and quorum-sensing autoinducer-2.
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Affiliation(s)
- Eric VanArsdale
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, MD 20742, USA
- Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD 20742, USA
| | - Juliana Pitzer
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Sally Wang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, MD 20742, USA
- Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD 20742, USA
| | - Kristina Stephens
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, MD 20742, USA
- Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD 20742, USA
| | - Chen-yu Chen
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, MD 20742, USA
- Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD 20742, USA
| | - Gregory F Payne
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, MD 20742, USA
- Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD 20742, USA
| | - William E Bentley
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, MD 20742, USA
- Fischell Institute for Biomedical Devices, University of Maryland, College Park, MD 20742, USA
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76
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Jäkel AC, Aufinger L, Simmel FC. Steady-State Operation of a Cell-Free Genetic Band-Detection Circuit. ACS Synth Biol 2022; 11:3273-3284. [PMID: 36095299 DOI: 10.1021/acssynbio.2c00195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Pattern formation processes play a decisive role during embryogenesis and involve the precise spatial and temporal orchestration of intricate gene regulatory processes. Synthetic gene circuits modeled after their biological counterparts can be used to investigate such processes under well-controlled conditions and may, in the future, be utilized for autonomous position determination in synthetic biological materials. Here, we investigated a three-node feed-forward gene regulatory circuit in vitro that generates three distinct fluorescent outputs in response to varying concentrations of a single externally supplied morphogen. The circuit acts as a band detector for the morphogen concentration and, in a spatial context, could serve as a stripe-forming gene circuit. We simulated the behavior of the genetic circuit in the presence of a morphogen gradient using a system of ordinary differential equations and determined optimal parameters for stripe-pattern formation using an evolutionary algorithm. To analyze the subcircuits of the system, we conducted cell-free characterization experiments and finally tested the whole genetic circuit in nanoliter-scale microfluidic flow reactors that provided a continuous supply of cell extract and metabolites and allowed removal of degradation products. To make use of the widely employed promoters PLlacO-1 and PLtetO-1 in our design, we removed LacI from our bacterial cell extract by genome engineering Escherichia coli using a pORTMAGE workflow. Our results show that the band-detector works as designed when operated out of equilibrium within the flow reactors. On the other hand, subcircuits of the system and the whole circuit fail to generate the desired gene expression response when operated in a closed reactor. Our work thus underlines the importance of out-of-equilibrium operation of complex gene circuits, which cannot settle to a steady-state expression pattern within the finite lifetime of a cell-free expression system.
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Affiliation(s)
- Anna C Jäkel
- Department of Bioscience, School of Natural Sciences, Technical University of Munich, Garching D-85748, Germany
| | - Lukas Aufinger
- Department of Bioscience, School of Natural Sciences, Technical University of Munich, Garching D-85748, Germany
| | - Friedrich C Simmel
- Department of Bioscience, School of Natural Sciences, Technical University of Munich, Garching D-85748, Germany
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77
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Scholz SA, Lindeboom CD, Freddolino PL. Genetic context effects can override canonical cis regulatory elements in Escherichia coli. Nucleic Acids Res 2022; 50:10360-10375. [PMID: 36134716 PMCID: PMC9561378 DOI: 10.1093/nar/gkac787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 08/10/2022] [Accepted: 09/02/2022] [Indexed: 11/12/2022] Open
Abstract
Recent experiments have shown that in addition to control by cis regulatory elements, the local chromosomal context of a gene also has a profound impact on its transcription. Although this chromosome-position dependent expression variation has been empirically mapped at high-resolution, the underlying causes of the variation have not been elucidated. Here, we demonstrate that 1 kb of flanking, non-coding synthetic sequences with a low frequency of guanosine and cytosine (GC) can dramatically reduce reporter expression compared to neutral and high GC-content flanks in Escherichia coli. Natural and artificial genetic context can have a similarly strong effect on reporter expression, regardless of cell growth phase or medium. Despite the strong reduction in the maximal expression level from the fully-induced reporter, low GC synthetic flanks do not affect the time required to reach the maximal expression level after induction. Overall, we demonstrate key determinants of transcriptional propensity that appear to act as tunable modulators of transcription, independent of regulatory sequences such as the promoter. These findings provide insight into the regulation of naturally occurring genes and an independent control for optimizing expression of synthetic biology constructs.
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Affiliation(s)
- Scott A Scholz
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Chase D Lindeboom
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Peter L Freddolino
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, USA
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78
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Kwak S, Crook N, Yoneda A, Ahn N, Ning J, Cheng J, Dantas G. Functional mining of novel terpene synthases from metagenomes. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:104. [PMID: 36209178 PMCID: PMC9548185 DOI: 10.1186/s13068-022-02189-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 07/29/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND Terpenes are one of the most diverse and abundant classes of natural biomolecules, collectively enabling a variety of therapeutic, energy, and cosmetic applications. Recent genomics investigations have predicted a large untapped reservoir of bacterial terpene synthases residing in the genomes of uncultivated organisms living in the soil, indicating a vast array of putative terpenoids waiting to be discovered. RESULTS We aimed to develop a high-throughput functional metagenomic screening system for identifying novel terpene synthases from bacterial metagenomes by relieving the toxicity of terpene biosynthesis precursors to the Escherichia coli host. The precursor toxicity was achieved using an inducible operon encoding the prenyl pyrophosphate synthetic pathway and supplementation of the mevalonate precursor. Host strain and screening procedures were finely optimized to minimize false positives arising from spontaneous mutations, which avoid the precursor toxicity. Our functional metagenomic screening of human fecal metagenomes yielded a novel β-farnesene synthase, which does not show amino acid sequence similarity to known β-farnesene synthases. Engineered S. cerevisiae expressing the screened β-farnesene synthase produced 120 mg/L β-farnesene from glucose (2.86 mg/g glucose) with a productivity of 0.721 g/L∙h. CONCLUSIONS A unique functional metagenomic screening procedure was established for screening terpene synthases from metagenomic libraries. This research proves the potential of functional metagenomics as a sequence-independent avenue for isolating targeted enzymes from uncultivated organisms in various environmental habitats.
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Affiliation(s)
- Suryang Kwak
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, 4515 McKinley Avenue, Room 5121, Campus Box 8510, Saint Louis, MO 63110 USA
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, Saint Louis, MO 63110 USA
| | - Nathan Crook
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, 4515 McKinley Avenue, Room 5121, Campus Box 8510, Saint Louis, MO 63110 USA
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, Saint Louis, MO 63110 USA
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695 USA
| | - Aki Yoneda
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, 4515 McKinley Avenue, Room 5121, Campus Box 8510, Saint Louis, MO 63110 USA
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, Saint Louis, MO 63110 USA
| | - Naomi Ahn
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, 4515 McKinley Avenue, Room 5121, Campus Box 8510, Saint Louis, MO 63110 USA
| | - Jie Ning
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, 4515 McKinley Avenue, Room 5121, Campus Box 8510, Saint Louis, MO 63110 USA
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, Saint Louis, MO 63110 USA
| | - Jiye Cheng
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, 4515 McKinley Avenue, Room 5121, Campus Box 8510, Saint Louis, MO 63110 USA
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, Saint Louis, MO 63110 USA
| | - Gautam Dantas
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, 4515 McKinley Avenue, Room 5121, Campus Box 8510, Saint Louis, MO 63110 USA
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, Saint Louis, MO 63110 USA
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO 63130 USA
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, Saint Louis, MO 63110 USA
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79
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Expanding the genetic toolkit helps dissect a global stress response in the early-branching species Fusobacterium nucleatum. Proc Natl Acad Sci U S A 2022; 119:e2201460119. [PMID: 36161895 PMCID: PMC9546586 DOI: 10.1073/pnas.2201460119] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Fusobacterium nucleatum, long known as a common oral microbe, has recently garnered attention for its ability to colonize tissues and tumors elsewhere in the human body. Clinical and epidemiological research has now firmly established F. nucleatum as an oncomicrobe associated with several major cancer types. However, with the current research focus on host associations, little is known about gene regulation in F. nucleatum itself, including global stress-response pathways that typically ensure the survival of bacteria outside their primary niche. This is due to the phylogenetic distance of Fusobacteriota to most model bacteria, their limited genetic tractability, and paucity of known gene functions. Here, we characterize a global transcriptional stress-response network governed by the extracytoplasmic function sigma factor, σE. To this aim, we developed several genetic tools for this anaerobic bacterium, including four different fluorescent marker proteins, inducible gene expression, scarless gene deletion, and transcriptional and translational reporter systems. Using these tools, we identified a σE response partly reminiscent of phylogenetically distant Proteobacteria but induced by exposure to oxygen. Although F. nucleatum lacks canonical RNA chaperones, such as Hfq, we uncovered conservation of the noncoding arm of the σE response in form of the noncoding RNA FoxI. This regulatory small RNA acts as an mRNA repressor of several membrane proteins, thereby supporting the function of σE. In addition to the characterization of a global stress response in F. nucleatum, the genetic tools developed here will enable further discoveries and dissection of regulatory networks in this early-branching bacterium.
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80
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A scalable framework for the discovery of functional helicase substrates and helicase-driven regulatory switches. Proc Natl Acad Sci U S A 2022; 119:e2209608119. [PMID: 36095194 PMCID: PMC9499579 DOI: 10.1073/pnas.2209608119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Helicases are ubiquitous motor enzymes that remodel nucleic acids (NA) and NA-protein complexes in key cellular processes. To explore the functional repertoire and specificity landscape of helicases, we devised a screening scheme-Helicase-SELEX (Systematic Evolution of Ligands by EXponential enrichment)-that enzymatically probes substrate and cofactor requirements at global scale. Using the transcription termination Rho helicase of Escherichia coli as a prototype for Helicase-SELEX, we generated a genome-wide map of Rho utilization (Rut) sites. The map reveals many features, including promoter- and intrinsic terminator-associated Rut sites, bidirectional Rut tandems, and cofactor-dependent Rut sites with inverted G > C skewed compositions. We also implemented an H-SELEX variant where we used a model ligand, serotonin, to evolve synthetic Rut sites operating in vitro and in vivo in a ligand-dependent manner. Altogether, our data illustrate the power and flexibility of Helicase-SELEX to seek constitutive or conditional helicase substrates in natural or synthetic NA libraries for fundamental or synthetic biology discovery.
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81
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Specht DA, Cortes LB, Lambert G. Overcoming Leak Sensitivity in CRISPRi Circuits Using Antisense RNA Sequestration and Regulatory Feedback. ACS Synth Biol 2022; 11:2927-2937. [PMID: 36017994 PMCID: PMC9486968 DOI: 10.1021/acssynbio.2c00155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Indexed: 01/24/2023]
Abstract
The controlled binding of the catalytically dead CRISPR nuclease (dCas) to DNA can be used to create complex, programmable transcriptional genetic circuits, a fundamental goal of synthetic biology. This approach, called CRISPR interference (CRISPRi), is advantageous over existing methods because the programmable nature of CRISPR proteins in principle enables the simultaneous regulation of many different targets without crosstalk. However, the performance of dCas-based genetic circuits is limited by both the sensitivity to leaky repression within CRISPRi logic gates and retroactive effects due to a shared pool of dCas proteins. By utilizing antisense RNAs (asRNAs) to sequester gRNA transcripts as well as CRISPRi feedback to self-regulate asRNA production, we demonstrate a mechanism that suppresses unwanted repression by CRISPRi and improves logical gene circuit function in Escherichia coli. This improvement is particularly pronounced during stationary expression when CRISPRi circuits do not achieve the expected regulatory dynamics. Furthermore, the use of dual CRISPRi/asRNA inverters restores the logical performance of layered circuits such as a double inverter. By studying circuit induction at the single-cell level in microfluidic channels, we provide insight into the dynamics of antisense sequestration of gRNA and regulatory feedback on dCas-based repression and derepression. These results demonstrate how CRISPRi inverters can be improved for use in more complex genetic circuitry without sacrificing the programmability and orthogonality of dCas proteins.
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Affiliation(s)
- David A. Specht
- Applied Physics, Cornell University, Ithaca, New York 14853, United States
| | - Louis B. Cortes
- Applied Physics, Cornell University, Ithaca, New York 14853, United States
| | - Guillaume Lambert
- Applied Physics, Cornell University, Ithaca, New York 14853, United States
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82
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Angermayr SA, Pang TY, Chevereau G, Mitosch K, Lercher MJ, Bollenbach T. Growth-mediated negative feedback shapes quantitative antibiotic response. Mol Syst Biol 2022; 18:e10490. [PMID: 36124745 PMCID: PMC9486506 DOI: 10.15252/msb.202110490] [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: 06/04/2021] [Revised: 08/19/2022] [Accepted: 08/26/2022] [Indexed: 11/15/2022] Open
Abstract
Dose–response relationships are a general concept for quantitatively describing biological systems across multiple scales, from the molecular to the whole‐cell level. A clinically relevant example is the bacterial growth response to antibiotics, which is routinely characterized by dose–response curves. The shape of the dose–response curve varies drastically between antibiotics and plays a key role in treatment, drug interactions, and resistance evolution. However, the mechanisms shaping the dose–response curve remain largely unclear. Here, we show in Escherichia coli that the distinctively shallow dose–response curve of the antibiotic trimethoprim is caused by a negative growth‐mediated feedback loop: Trimethoprim slows growth, which in turn weakens the effect of this antibiotic. At the molecular level, this feedback is caused by the upregulation of the drug target dihydrofolate reductase (FolA/DHFR). We show that this upregulation is not a specific response to trimethoprim but follows a universal trend line that depends primarily on the growth rate, irrespective of its cause. Rewiring the feedback loop alters the dose–response curve in a predictable manner, which we corroborate using a mathematical model of cellular resource allocation and growth. Our results indicate that growth‐mediated feedback loops may shape drug responses more generally and could be exploited to design evolutionary traps that enable selection against drug resistance.
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Affiliation(s)
- S Andreas Angermayr
- Institute for Biological Physics, University of Cologne, Cologne, Germany.,Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Tin Yau Pang
- Institute for Computer Science, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,Department of Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | | | - Karin Mitosch
- Institute of Science and Technology Austria, Klosterneuburg, Austria.,Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Martin J Lercher
- Institute for Computer Science, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,Department of Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Tobias Bollenbach
- Institute for Biological Physics, University of Cologne, Cologne, Germany.,Center for Data and Simulation Science, University of Cologne, Cologne, Germany
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83
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Chang S, Thrall ES, Laureti L, Piatt SC, Pagès V, Loparo JJ. Compartmentalization of the replication fork by single-stranded DNA-binding protein regulates translesion synthesis. Nat Struct Mol Biol 2022; 29:932-941. [PMID: 36127468 PMCID: PMC9509481 DOI: 10.1038/s41594-022-00827-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/28/2022] [Indexed: 11/09/2022]
Abstract
Processivity clamps tether DNA polymerases to DNA, allowing their access to the primer-template junction. In addition to DNA replication, DNA polymerases also participate in various genome maintenance activities, including translesion synthesis (TLS). However, owing to the error-prone nature of TLS polymerases, their association with clamps must be tightly regulated. Here we show that fork-associated ssDNA-binding protein (SSB) selectively enriches the bacterial TLS polymerase Pol IV at stalled replication forks. This enrichment enables Pol IV to associate with the processivity clamp and is required for TLS on both the leading and lagging strands. In contrast, clamp-interacting proteins (CLIPs) lacking SSB binding are spatially segregated from the replication fork, minimally interfering with Pol IV-mediated TLS. We propose that stalling-dependent structural changes within clusters of fork-associated SSB establish hierarchical access to the processivity clamp. This mechanism prioritizes a subset of CLIPs with SSB-binding activity and facilitates their exchange at the replication fork.
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Affiliation(s)
- Seungwoo Chang
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Elizabeth S Thrall
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Chemistry, Fordham University, New York City, NY, USA
| | - Luisa Laureti
- CRCM (Cancer Research Center of Marseille): Team DNA Damage and Genome Instability, Aix-Marseille University, CNRS, INSERM, Institut Paoli-Calmettes, Marseille, France
| | - Sadie C Piatt
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Harvard Graduate Program in Biophysics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Vincent Pagès
- CRCM (Cancer Research Center of Marseille): Team DNA Damage and Genome Instability, Aix-Marseille University, CNRS, INSERM, Institut Paoli-Calmettes, Marseille, France
| | - Joseph J Loparo
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
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84
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Hinenoya A, Wang H, Patrick EM, Zeng X, Cao L, Li XP, Lindsey RL, Gillespie B, He Q, Yamasaki S, Lin J. Longitudinal surveillance and comparative characterization of Escherichia albertii in wild raccoons in the United States. Microbiol Res 2022; 262:127109. [DOI: 10.1016/j.micres.2022.127109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 10/17/2022]
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85
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Dundas CM, Dinneny JR. Genetic Circuit Design in Rhizobacteria. BIODESIGN RESEARCH 2022; 2022:9858049. [PMID: 37850138 PMCID: PMC10521742 DOI: 10.34133/2022/9858049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 07/31/2022] [Indexed: 10/19/2023] Open
Abstract
Genetically engineered plants hold enormous promise for tackling global food security and agricultural sustainability challenges. However, construction of plant-based genetic circuitry is constrained by a lack of well-characterized genetic parts and circuit design rules. In contrast, advances in bacterial synthetic biology have yielded a wealth of sensors, actuators, and other tools that can be used to build bacterial circuitry. As root-colonizing bacteria (rhizobacteria) exert substantial influence over plant health and growth, genetic circuit design in these microorganisms can be used to indirectly engineer plants and accelerate the design-build-test-learn cycle. Here, we outline genetic parts and best practices for designing rhizobacterial circuits, with an emphasis on sensors, actuators, and chassis species that can be used to monitor/control rhizosphere and plant processes.
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Affiliation(s)
| | - José R. Dinneny
- Department of Biology, Stanford University, Stanford, CA 94305, USA
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86
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Lebovich M, Andrews LB. Surveying the Genetic Design Space for Transcription Factor-Based Metabolite Biosensors: Synthetic Gamma-Aminobutyric Acid and Propionate Biosensors in E. coli Nissle 1917. Front Bioeng Biotechnol 2022; 10:938056. [PMID: 36091463 PMCID: PMC9452892 DOI: 10.3389/fbioe.2022.938056] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/22/2022] [Indexed: 11/25/2022] Open
Abstract
Engineered probiotic bacteria have been proposed as a next-generation strategy for noninvasively detecting biomarkers in the gastrointestinal tract and interrogating the gut-brain axis. A major challenge impeding the implementation of this strategy has been the difficulty to engineer the necessary whole-cell biosensors. Creation of transcription factor-based biosensors in a clinically-relevant strain often requires significant tuning of the genetic parts and gene expression to achieve the dynamic range and sensitivity required. Here, we propose an approach to efficiently engineer transcription-factor based metabolite biosensors that uses a design prototyping construct to quickly assay the gene expression design space and identify an optimal genetic design. We demonstrate this approach using the probiotic bacterium Escherichia coli Nissle 1917 (EcN) and two neuroactive gut metabolites: the neurotransmitter gamma-aminobutyric acid (GABA) and the short-chain fatty acid propionate. The EcN propionate sensor, utilizing the PrpR transcriptional activator from E. coli, has a large 59-fold dynamic range and >500-fold increased sensitivity that matches biologically-relevant concentrations. Our EcN GABA biosensor uses the GabR transcriptional repressor from Bacillus subtilis and a synthetic GabR-regulated promoter created in this study. This work reports the first known synthetic microbial whole-cell biosensor for GABA, which has an observed 138-fold activation in EcN at biologically-relevant concentrations. Using this rapid design prototyping approach, we engineer highly functional biosensors for specified in vivo metabolite concentrations that achieve a large dynamic range and high output promoter activity upon activation. This strategy may be broadly useful for accelerating the engineering of metabolite biosensors for living diagnostics and therapeutics.
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Affiliation(s)
- Matthew Lebovich
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, United States
- Biotechnology Training Program, University of Massachusetts Amherst, Amherst, MA, United States
| | - Lauren B. Andrews
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, United States
- Biotechnology Training Program, University of Massachusetts Amherst, Amherst, MA, United States
- Molecular and Cellular Biology Graduate, Program University of Massachusetts Amherst, Amherst, MA, United States
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87
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Zúñiga A, Muñoz-Guamuro G, Boivineau L, Mayonove P, Conejero I, Pageaux GP, Altwegg R, Bonnet J. A rapid and standardized workflow for functional assessment of bacterial biosensors in fecal samples. Front Bioeng Biotechnol 2022; 10:859600. [PMID: 36072290 PMCID: PMC9444133 DOI: 10.3389/fbioe.2022.859600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 07/05/2022] [Indexed: 11/17/2022] Open
Abstract
Gut metabolites are pivotal mediators of host-microbiome interactions and provide an important window on human physiology and disease. However, current methods to monitor gut metabolites rely on heavy and expensive technologies such as liquid chromatography-mass spectrometry (LC-MS). In that context, robust, fast, field-deployable, and cost-effective strategies for monitoring fecal metabolites would support large-scale functional studies and routine monitoring of metabolites biomarkers associated with pathological conditions. Living cells are an attractive option to engineer biosensors due to their ability to detect and process many environmental signals and their self-replicating nature. Here we optimized a workflow for feces processing that supports metabolite detection using bacterial biosensors. We show that simple centrifugation and filtration steps remove host microbes and support reproducible preparation of a physiological-derived media retaining important characteristics of human feces, such as matrix effects and endogenous metabolites. We measure the performance of bacterial biosensors for benzoate, lactate, anhydrotetracycline, and bile acids, and find that they are highly sensitive to fecal matrices. However, encapsulating the bacteria in hydrogel helps reduce this inhibitory effect. Sensitivity to matrix effects is biosensor-dependent but also varies between individuals, highlighting the need for case-by-case optimization for biosensors’ operation in feces. Finally, by detecting endogenous bile acids, we demonstrate that bacterial biosensors could be used for future metabolite monitoring in feces. This work lays the foundation for the optimization and use of bacterial biosensors for fecal metabolites monitoring. In the future, our method could also allow rapid pre-prototyping of engineered bacteria designed to operate in the gut, with applications to in situ diagnostics and therapeutics.
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Affiliation(s)
- Ana Zúñiga
- Centre de Biologie Structurale (CBS), INSERM U1054, CNRS UMR5048, University of Montpellier, Montpellier, France
- *Correspondence: Ana Zúñiga, ; Jerome Bonnet,
| | - Geisler Muñoz-Guamuro
- Centre de Biologie Structurale (CBS), INSERM U1054, CNRS UMR5048, University of Montpellier, Montpellier, France
| | - Lucile Boivineau
- Hepatogastroenterology and Bacteriology Service at CHU Montpellier, University of Montpellier, Montpellier, France
| | - Pauline Mayonove
- Centre de Biologie Structurale (CBS), INSERM U1054, CNRS UMR5048, University of Montpellier, Montpellier, France
| | - Ismael Conejero
- Department of Psychiatry, CHU Nimes, University of Montpellier, Montpellier, France
| | - Georges-Philippe Pageaux
- Hepatogastroenterology and Bacteriology Service at CHU Montpellier, University of Montpellier, Montpellier, France
| | - Romain Altwegg
- Hepatogastroenterology and Bacteriology Service at CHU Montpellier, University of Montpellier, Montpellier, France
| | - Jerome Bonnet
- Centre de Biologie Structurale (CBS), INSERM U1054, CNRS UMR5048, University of Montpellier, Montpellier, France
- *Correspondence: Ana Zúñiga, ; Jerome Bonnet,
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88
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Liu YX, Zhuo XZ, Li SY. The Transcription Activator AtxA from Bacillus Anthracis was Employed for Developing a Tight-Control, High-Level, Modulable, and Stationary-Phase Specific Transcription Activity in Escherichia Coli. Synth Biol (Oxf) 2022; 7:ysac014. [PMID: 36046151 PMCID: PMC9424709 DOI: 10.1093/synbio/ysac014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 06/16/2022] [Accepted: 08/16/2022] [Indexed: 11/13/2022] Open
Abstract
The strong transcriptional activity of the virulent gene pagA in Bacillus anthracis has been proven to be anthrax toxin activator (AtxA)-regulated. However, the obscure pagA transcription mechanism hinders practical applications of this strong promoter. In this study, a 509-bp DNA fragment [termed 509sequence, (−508)-(+1) relative to the P2 transcription start site] was cloned upstream of rbs-GFPuv as pTOL02B to elucidate the AtxA-regulated transcription. The 509sequence was dissected into the −10 sequence, −35 sequence, ATrich tract, SLI/SLII and upstream site. In conjunction with the heterologous co-expression of AtxA (under the control of the T7 promoter), the −10 sequence (TATACT) was sufficient for the AtxA-regulated transcription. Integration of pTOL02F + pTOLAtxA as pTOL03F showed that the AtxA-regulated transcription exhibited a strong specific fluorescence intensity/common analytical chemistry term (OD600) of 40 597 ± 446 and an induction/repression ratio of 122. An improved induction/repression ratio of 276 was achieved by cultivating Escherichia coli/pTOL03F in M9 minimal medium. The newly developed promoter system termed PAtxA consists of AtxA, the −10 sequence and Escherichia RNA polymerase. These three elements synergistically and cooperatively formed a previously undiscovered transcription system, which exhibited a tight-control, high-level, modulable and stationary-phase-specific transcription. The PAtxA was used for phaCAB expression for the stationary-phase polyhydroxybutyrate production, and the results showed that a PHB yield, content and titer of 0.20 ± 0.27 g/g-glucose, 68 ± 11% and 1.5 ± 0.4 g/l can be obtained. The positive inducible PAtxA, in contrast to negative inducible, should be a useful tool to diversify the gene information flow in synthetic biology.
Graphical Abstract
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Affiliation(s)
- Ying-Xing Liu
- Department of Chemical Engineering, National Chung Hsing University , Taichung 402, Taiwan
| | - Xiao-Zhen Zhuo
- Department of Chemical Engineering, National Chung Hsing University , Taichung 402, Taiwan
| | - Si-Yu Li
- Department of Chemical Engineering, National Chung Hsing University , Taichung 402, Taiwan
- Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University , Taichung 402, Taiwan
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89
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Li X, Jiang W, Qi Q, Liang Q. A Gene Circuit Combining the Endogenous I-E Type CRISPR-Cas System and a Light Sensor to Produce Poly-β-Hydroxybutyric Acid Efficiently. BIOSENSORS 2022; 12:bios12080642. [PMID: 36005038 PMCID: PMC9405541 DOI: 10.3390/bios12080642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/08/2022] [Accepted: 08/12/2022] [Indexed: 11/23/2022]
Abstract
‘Metabolic burden,’ which arises when introducing exogenic synthesizing pathways into a host strain, remains a challenging issue in metabolic engineering. Redirecting metabolic flux from cell growth to product synthesis at an appropriate culture timepoint is ideal for resolving this issue. In this report, we introduce optogenetics—which is capable of precise temporal and spatial control—as a genetic switch, accompanied by the endogenous type I-E CRISPRi system in Escherichia coli (E. coli) to generate a metabolic platform that redirects metabolic flux. Poly-β-hydroxybutyric acid (PHB) production was taken as an example to demonstrate the performance of this platform. A two-to-three-fold increase in PHB content was observed under green light when compared with the production of PHB under red light, confirming the regulatory activity of this platform and its potential to redirect metabolic flux to synthesize target products.
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Affiliation(s)
- Xiaomeng Li
- State Key Laboratory of Microbial Technology, Shandong University, No. 72, Binhai Road, Qingdao 266237, China
- The Second Laboratory of Lanzhou Institute of Biological Products Co., Ltd., No. 888, Yanchang Road, Lanzhou 730046, China
| | - Wei Jiang
- Research Center of Basic Medicine, Central Hospital Affiliated to Shandong First Medical University, No. 105, Jiefang Road, Jinan 250013, China
| | - Qingsheng Qi
- State Key Laboratory of Microbial Technology, Shandong University, No. 72, Binhai Road, Qingdao 266237, China
| | - Quanfeng Liang
- State Key Laboratory of Microbial Technology, Shandong University, No. 72, Binhai Road, Qingdao 266237, China
- Correspondence: ; Tel.: +86-13573163779
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90
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Bubnov DM, Yuzbashev TV, Khozov AA, Melkina OE, Vybornaya TV, Stan GB, Sineoky SP. Robust counterselection and advanced λRed recombineering enable markerless chromosomal integration of large heterologous constructs. Nucleic Acids Res 2022; 50:8947-8960. [PMID: 35920321 PMCID: PMC9410887 DOI: 10.1093/nar/gkac649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 07/07/2022] [Accepted: 07/20/2022] [Indexed: 11/17/2022] Open
Abstract
Despite advances in bacterial genome engineering, delivery of large synthetic constructs remains challenging in practice. In this study, we propose a straightforward and robust approach for the markerless integration of DNA fragments encoding whole metabolic pathways into the genome. This approach relies on the replacement of a counterselection marker with cargo DNA cassettes via λRed recombineering. We employed a counterselection strategy involving a genetic circuit based on the CI repressor of λ phage. Our design ensures elimination of most spontaneous mutants, and thus provides a counterselection stringency close to the maximum possible. We improved the efficiency of integrating long PCR-generated cassettes by exploiting the Ocr antirestriction function of T7 phage, which completely prevents degradation of unmethylated DNA by restriction endonucleases in wild-type bacteria. The employment of highly restrictive counterselection and ocr-assisted λRed recombineering allowed markerless integration of operon-sized cassettes into arbitrary genomic loci of four enterobacterial species with an efficiency of 50–100%. In the case of Escherichia coli, our strategy ensures simple combination of markerless mutations in a single strain via P1 transduction. Overall, the proposed approach can serve as a general tool for synthetic biology and metabolic engineering in a range of bacterial hosts.
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Affiliation(s)
- Dmitrii M Bubnov
- Bioresource Center Russian National Collection of Industrial Microorganisms (BRC VKPM), State Research Institute for Genetics and Selection of Industrial Microorganisms of National Research Center 'Kurchatov Institute' (NRC 'Kurchatov Institute' - GosNIIgenetika), 1-st Dorozhny pr., 1, Moscow 117545, Russia.,Kurchatov Complex of Genetic Research, NRC 'Kurchatov Institute', Kurchatov Square, 1, Moscow 123098, Russia
| | - Tigran V Yuzbashev
- Department of Bioengineering and Imperial College Centre for Synthetic Biology, Imperial College London, London SW7 2AZ, UK
| | - Andrey A Khozov
- Bioresource Center Russian National Collection of Industrial Microorganisms (BRC VKPM), State Research Institute for Genetics and Selection of Industrial Microorganisms of National Research Center 'Kurchatov Institute' (NRC 'Kurchatov Institute' - GosNIIgenetika), 1-st Dorozhny pr., 1, Moscow 117545, Russia.,Kurchatov Complex of Genetic Research, NRC 'Kurchatov Institute', Kurchatov Square, 1, Moscow 123098, Russia.,Department of Microbiology, Faculty of Biology, Lomonosov Moscow State University, Lenin's Hills 1-12, Moscow 119234, Russia
| | - Olga E Melkina
- Kurchatov Complex of Genetic Research, NRC 'Kurchatov Institute', Kurchatov Square, 1, Moscow 123098, Russia.,Laboratory of Bacterial Genetics, NRC 'Kurchatov Institute' - GosNIIgenetika, 1-st Dorozhny pr., 1, Moscow 117545, Russia
| | - Tatiana V Vybornaya
- Bioresource Center Russian National Collection of Industrial Microorganisms (BRC VKPM), State Research Institute for Genetics and Selection of Industrial Microorganisms of National Research Center 'Kurchatov Institute' (NRC 'Kurchatov Institute' - GosNIIgenetika), 1-st Dorozhny pr., 1, Moscow 117545, Russia.,Kurchatov Genomic Center, NRC 'Kurchatov Institute' - GosNIIgenetika, 1-st Dorozhny pr., 1, Moscow 117545, Russia
| | - Guy-Bart Stan
- Department of Bioengineering and Imperial College Centre for Synthetic Biology, Imperial College London, London SW7 2AZ, UK
| | - Sergey P Sineoky
- Bioresource Center Russian National Collection of Industrial Microorganisms (BRC VKPM), State Research Institute for Genetics and Selection of Industrial Microorganisms of National Research Center 'Kurchatov Institute' (NRC 'Kurchatov Institute' - GosNIIgenetika), 1-st Dorozhny pr., 1, Moscow 117545, Russia.,Kurchatov Complex of Genetic Research, NRC 'Kurchatov Institute', Kurchatov Square, 1, Moscow 123098, Russia
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91
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Jadhav P, Chen Y, Butzin N, Buceta J, Urchueguía A. Bacterial degrons in synthetic circuits. Open Biol 2022; 12:220180. [PMID: 35975648 PMCID: PMC9382460 DOI: 10.1098/rsob.220180] [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] [Indexed: 11/18/2022] Open
Abstract
Bacterial proteases are a promising post-translational regulation strategy in synthetic circuits because they recognize specific amino acid degradation tags (degrons) that can be fine-tuned to modulate the degradation levels of tagged proteins. For this reason, recent efforts have been made in the search for new degrons. Here we review the up-to-date applications of degradation tags for circuit engineering in bacteria. In particular, we pay special attention to the effects of degradation bottlenecks in synthetic oscillators and introduce mathematical approaches to study queueing that enable the quantitative modelling of proteolytic queues.
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Affiliation(s)
- Prajakta Jadhav
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA
| | - Yanyan Chen
- Program for Computational and Systems Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Nicholas Butzin
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA
| | - Javier Buceta
- Institute for Integrative Systems Biology (I2SysBio, CSIC-UV), Paterna, Valencia 46980, Spain
| | - Arantxa Urchueguía
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA.,Institute for Integrative Systems Biology (I2SysBio, CSIC-UV), Paterna, Valencia 46980, Spain
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92
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Deter HS, Lu T. Engineering microbial consortia with rationally designed cellular interactions. Curr Opin Biotechnol 2022; 76:102730. [PMID: 35609504 PMCID: PMC10129393 DOI: 10.1016/j.copbio.2022.102730] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 03/22/2022] [Accepted: 04/03/2022] [Indexed: 12/14/2022]
Abstract
Synthetic microbial consortia represent a frontier of synthetic biology that promises versatile engineering of cellular functions. They are primarily developed through the design and construction of cellular interactions that coordinate individual dynamics and generate collective behaviors. Here we review recent advances in the engineering of synthetic communities through cellular-interaction programming. We first examine fundamental building blocks for intercellular communication and unidirectional positive and negative interactions. We then recap the assembly of the building blocks for creating bidirectional interactions in two-species ecosystems, which is followed by the discussion of engineering toward complex communities with increasing species numbers, under spatial contexts, and via model-guided design. We conclude by summarizing major challenges and future opportunities of engineered microbial ecosystems.
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Affiliation(s)
- Heather S Deter
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL, USA; Intelligence Community Postdoctoral Research Fellowship Program, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - Ting Lu
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL, USA; Department of Physics, University of Illinois Urbana-Champaign, Urbana, IL, USA; Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, IL, USA; National Center for Supercomputing Applications, Urbana, IL, USA.
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93
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Zomorrodi AR, Hemez C, Arranz-Gibert P, Wu T, Isaacs FJ, Segrè D. Computational design and engineering of an Escherichia coli strain producing the nonstandard amino acid para-aminophenylalanine. iScience 2022; 25:104562. [PMID: 35789833 PMCID: PMC9249619 DOI: 10.1016/j.isci.2022.104562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 05/16/2022] [Accepted: 06/02/2022] [Indexed: 11/16/2022] Open
Abstract
Introducing heterologous pathways into host cells constitutes a promising strategy for synthesizing nonstandard amino acids (nsAAs) to enable the production of proteins with expanded chemistries. However, this strategy has proven challenging, as the expression of heterologous pathways can disrupt cellular homeostasis of the host cell. Here, we sought to optimize the heterologous production of the nsAA para-aminophenylalanine (pAF) in Escherichia coli. First, we incorporated a heterologous pAF biosynthesis pathway into a genome-scale model of E. coli metabolism and computationally identified metabolic interventions in the host’s native metabolism to improve pAF production. Next, we explored different approaches of imposing these flux interventions experimentally and found that the upregulation of flux in the chorismate biosynthesis pathway through the elimination of feedback inhibition mechanisms could significantly raise pAF titers (∼20-fold) while maintaining a reasonable pAF production-growth rate trade-off. Overall, this study provides a promising strategy for the biosynthesis of nsAAs in engineered cells. Sought to optimize para-aminophenylalanine (pAF) production and growth in E. coli Identified interventions in the host native metabolism using genome-scale models Constructed multiple mutant strains involving gene knockouts and/or overexpressions Flux modification in chorismate biosynthesis pathway significantly raised pAF titer
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Affiliation(s)
- Ali R. Zomorrodi
- Mucosal Immunology and Biology Research Center, Pediatrics Department, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
- Bioinformatics Graduate Program, Boston University, Boston, MA, USA
| | - Colin Hemez
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
- Systems Biology Institute, Yale University, West Haven, CT, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Pol Arranz-Gibert
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
- Systems Biology Institute, Yale University, West Haven, CT, USA
| | - Terrence Wu
- Yale West Campus Analytical Core, 600 West Campus Drive, West Haven, USA
| | - Farren J. Isaacs
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
- Systems Biology Institute, Yale University, West Haven, CT, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
- Corresponding author
| | - Daniel Segrè
- Bioinformatics Graduate Program, Boston University, Boston, MA, USA
- Department of Biology, Boston University, Boston, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
- Biological Design Center, Boston University, Boston, MA, USA
- Corresponding author
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94
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Abstract
Bacteriophage Mu is a paradigm coliphage studied mainly because of its use of transposition for genome replication. However, in extensive nonsense mutant screens, only one lysis gene has been identified, the endolysin gp22. This is surprising because in Gram-negative hosts, lysis by Caudovirales phages has been shown to require proteins which disrupt all three layers of the cell envelope. Usually this involves a holin, an endolysin, and a spanin targeting the cytoplasmic membrane, peptidoglycan (PG), and outer membrane (OM), respectively, with the holin determining the timing of lysis initiation. Here, we demonstrate that gp22 is a signal-anchor-release (SAR) endolysin and identify gp23 and gp23.1 as two-component spanin subunits. However, we find that Mu lacks a holin and instead encodes a membrane-tethered cytoplasmic protein, gp25, which is required for the release of the SAR endolysin. Mutational analysis showed that this dependence on gp25 is conferred by lysine residues at positions 6 and 7 of the short cytoplasmic domain of gp22. gp25, which we designate as a releasin, also facilitates the release of SAR endolysins from other phages. Moreover, the entire length of gp25, including its N-terminal transmembrane domain, belongs to a protein family, DUF2730, found in many Mu-like phages, including those with cytoplasmic endolysins. These results are discussed in terms of models for the evolution and mechanism of releasin function and a rationale for Mu lysis without holin control. IMPORTANCE Host cell lysis is the terminal event of the bacteriophage infection cycle. In Gram-negative hosts, lysis requires proteins that disrupt each of the three cell envelope components, only one of which has been identified in Mu: the endolysin gp22. We show that gp22 can be characterized as a SAR endolysin, a muralytic enzyme that activates upon release from the membrane to degrade the cell wall. Furthermore, we identify genes 23 and 23.1 as spanin subunits used for outer membrane disruption. Significantly, we demonstrate that Mu is the first known Caudovirales phage to lack a holin, a protein that disrupts the inner membrane and is traditionally known to release endolysins. In its stead, we report the discovery of a lysis protein, termed the releasin, which Mu uses for SAR endolysin release. This is an example of a system where the dynamic membrane localization of one protein is controlled by a secondary protein.
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95
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L.B. Almeida B, M. Bahrudeen MN, Chauhan V, Dash S, Kandavalli V, Häkkinen A, Lloyd-Price J, S.D. Cristina P, Baptista ISC, Gupta A, Kesseli J, Dufour E, Smolander OP, Nykter M, Auvinen P, Jacobs HT, M.D. Oliveira S, S. Ribeiro A. The transcription factor network of E. coli steers global responses to shifts in RNAP concentration. Nucleic Acids Res 2022; 50:6801-6819. [PMID: 35748858 PMCID: PMC9262627 DOI: 10.1093/nar/gkac540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 06/02/2022] [Accepted: 06/14/2022] [Indexed: 12/24/2022] Open
Abstract
The robustness and sensitivity of gene networks to environmental changes is critical for cell survival. How gene networks produce specific, chronologically ordered responses to genome-wide perturbations, while robustly maintaining homeostasis, remains an open question. We analysed if short- and mid-term genome-wide responses to shifts in RNA polymerase (RNAP) concentration are influenced by the known topology and logic of the transcription factor network (TFN) of Escherichia coli. We found that, at the gene cohort level, the magnitude of the single-gene, mid-term transcriptional responses to changes in RNAP concentration can be explained by the absolute difference between the gene's numbers of activating and repressing input transcription factors (TFs). Interestingly, this difference is strongly positively correlated with the number of input TFs of the gene. Meanwhile, short-term responses showed only weak influence from the TFN. Our results suggest that the global topological traits of the TFN of E. coli shape which gene cohorts respond to genome-wide stresses.
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Affiliation(s)
- Bilena L.B. Almeida
- Correspondence may also be addressed to Bilena L.B. Almeida. Tel: +358 2945211;
| | | | | | | | - Vinodh Kandavalli
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Antti Häkkinen
- Research Program in Systems Oncology, Research Programs Unit, Faculty of Medicine, University of Helsinki, FI-00014 Helsinki, Finland
| | | | - Palma S.D. Cristina
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Ines S C Baptista
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Abhishekh Gupta
- Center for Quantitative Medicine and Department of Cell Biology, University of Connecticut School of Medicine, 263 Farmington Av., Farmington, CT 06030-6033, USA
| | - Juha Kesseli
- Prostate Cancer Research Center, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland; Tays Cancer Center, Tampere University Hospital, Tampere, Finland
| | - Eric Dufour
- Mitochondrial bioenergetics and metabolism, BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Olli-Pekka Smolander
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
- Institute of Biotechnology, University of Helsinki, Viikinkaari 5D, 00790 Helsinki, Finland
| | - Matti Nykter
- Prostate Cancer Research Center, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland; Tays Cancer Center, Tampere University Hospital, Tampere, Finland
| | - Petri Auvinen
- Institute of Biotechnology, University of Helsinki, Viikinkaari 5D, 00790 Helsinki, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland; Department of Environment and Genetics, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Samuel M.D. Oliveira
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, USA
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96
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Fulk EM, Gao X, Lu LC, Redeker KR, Masiello CA, Silberg JJ. Nondestructive Chemical Sensing within Bulk Soil Using 1000 Biosensors Per Gram of Matrix. ACS Synth Biol 2022; 11:2372-2383. [PMID: 35715210 DOI: 10.1021/acssynbio.2c00083] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Gene expression can be monitored in hard-to-image environmental materials using gas-reporting biosensors, but these outputs have only been applied in autoclaved matrices that are hydrated with rich medium. To better understand the compatibility of indicator gas reporting with environmental samples, we evaluated how matrix hydration affects the gas signal of an engineered microbe added to a sieved soil. A gas-reporting microbe presented a gas signal in a forest soil (Alfisol) when hydrated to an environmentally relevant osmotic pressure. When the gas signal was concentrated prior to analysis, a biosensor titer of 103 cells/gram of soil produced a significant signal when soil was supplemented with halides. A signal was also observed without halide amendment, but a higher cell titer (106 cells/gram of soil) was required. A sugar-regulated gas biosensor was able to report with a similar level of sensitivity when added to an unsterilized soil matrix, illustrating how gas concentration enables biosensing within a soil containing environmental microbes. These results establish conditions where engineered microbes can report on gene expression in living environmental matrices with decreased perturbation of the soil environment compared to previously reported approaches, using biosensor titers that are orders of magnitude lower than the number of cells typically observed in a gram of soil.
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Affiliation(s)
- Emily M Fulk
- Systems, Synthetic, and Physical Biology Graduate Program, Rice University, 6100 Main Street, MS-180, Houston, Texas 77005, United States
| | - Xiaodong Gao
- Department of Earth, Environmental and Planetary Sciences, Rice University, 6100 Main St, MS-126, Houston, Texas 77005, United States
| | - Li Chieh Lu
- Department of Biosciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States
| | - Kelly R Redeker
- Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Caroline A Masiello
- Department of Earth, Environmental and Planetary Sciences, Rice University, 6100 Main St, MS-126, Houston, Texas 77005, United States.,Department of Biosciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States.,Department of Chemistry, Rice University, 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Jonathan J Silberg
- Department of Biosciences, Rice University, 6100 Main Street, MS-140, Houston, Texas 77005, United States.,Department of Bioengineering, Rice University, 6100 Main Street, MS-142, Houston, Texas 77005, United States.,Department of Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, MS-362, Houston, Texas 77005, United States
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97
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Gong X, Zhang R, Wang J, Yan Y. Engineering of a TrpR-Based Biosensor for Altered Dynamic Range and Ligand Preference. ACS Synth Biol 2022; 11:2175-2183. [PMID: 35594503 PMCID: PMC10947557 DOI: 10.1021/acssynbio.2c00134] [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] [Indexed: 11/28/2022]
Abstract
Transcriptional factors play a crucial role in regulating cellular functions. Understanding and altering the dynamic behavior of the transcriptional factor-based biosensors will expand our knowledge in investigating biomolecular interactions and facilitating biosynthetic applications. In this study, we characterized and engineered a TrpR-based tryptophan repressor system in Escherichia coli. We found that the reconstructed TrpR1-PtrpO1 biosensor system exhibited low basal expression and narrow dynamic range in the presence of tryptophan or its analogue 5-hydroxytryptophan (5-HTP). Given the application potential of the biosensor, we introduced engineering approaches in multiple levels to optimize its dynamic behavior. First, the I57 and V58 residues in the ligand-binding pocket were rationally mutated in search of variants with altered ligand specificity. Two TrpR1 variants, V58E and V58K, successfully acquired ligand preference toward tryptophan and 5-HTP, respectively. The biosensor-induced expression levels were increased up to 10-fold with those variants. Furthermore, to pursue broader operational range, we tuned the regulator-operator binding affinity by mutating the binding box of TrpR1. Collectively, we demonstrated that the biosynthesis-significant biosensor TrpR1-PtrpO1 can be engineered to acquire extended dynamic ranges and improved ligand preference. The engineered biosensor variants with remarkable dynamic behavior can serve as key genetic elements in high-throughput screening and dynamic regulation in biosynthetic scenarios.
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Affiliation(s)
- Xinyu Gong
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA 30602, USA
| | - Ruihua Zhang
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA 30602, USA
| | - Jian Wang
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA 30602, USA
| | - Yajun Yan
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, GA 30602, USA
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98
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Wang Z, Yan Y, Zhang H. A Single-Component Blue Light-Induced System Based on EL222 in Yarrowia lipolytica. Int J Mol Sci 2022; 23:ijms23116344. [PMID: 35683022 PMCID: PMC9181742 DOI: 10.3390/ijms23116344] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/20/2022] [Accepted: 06/02/2022] [Indexed: 01/27/2023] Open
Abstract
Optogenetics has the advantages of a fast response time, reversibility, and high spatial and temporal resolution, which make it desirable in the metabolic engineering of chassis cells. In this study, a light-induced expression system of Yarrowia lipolytica was constructed, which successfully achieved the synthesis and functional verification of Bleomycin resistance protein (BleoR). The core of the blue light-induced system, the light-responsive element (TF), is constructed based on the blue photosensitive protein EL222 and the transcription activator VP16. The results show that the light-induced sensor based on TF, upstream activation sequence (C120)5, and minimal promoter CYC102 can respond to blue light and initiate the expression of GFPMut3 report gene. With four copies of the responsive promoter and reporter gene assembled, they can produce a 128.5-fold higher fluorescent signal than that under dark conditions after 8 h of induction. The effects of light dose and periodicity on this system were investigated, which proved that the system has good spatial and temporal controllability. On this basis, the light-controlled system was used for the synthesis of BleoR to realize the expression and verification of functional protein. These results demonstrated that this system has the potential for the transcriptional regulation of target genes, construction of large-scale synthetic networks, and overproduction of the desired product.
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99
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Davenport BI, Tica J, Isalan M. Reducing metabolic burden in the PACEmid evolver system by remastering high-copy phagemid vectors. ENGINEERING BIOLOGY 2022; 6:50-61. [PMID: 36969104 PMCID: PMC9996709 DOI: 10.1049/enb2.12021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 04/07/2022] [Accepted: 04/20/2022] [Indexed: 01/12/2023] Open
Abstract
Orthogonal or non-cross-reacting transcription factors are used in synthetic biology as components of genetic circuits. Brödel et al. (2016) engineered 12 such cIλ transcription factor variants using a directed evolution 'PACEmid' system. The variants operate as dual activator/repressors and expand gene circuit construction possibilities. However, the high-copy phagemid vectors carrying the cIλ variants imposed high metabolic burden upon cells. Here, the authors 'remaster' the phagemid backbones to relieve their burden substantially, exhibited by a recovery in Escherichia coli growth. The remastered phagemids' ability to function within the PACEmid evolver system is maintained, as is the cIλ transcription factors' activity within these vectors. The low-burden phagemid versions are more suitable for use in PACEmid experiments and synthetic gene circuits; the authors have, therefore, replaced the original high-burden phagemids on the Addgene repository. The authors' work emphasises the importance of understanding metabolic burden and incorporating it into design steps in future synthetic biology ventures.
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Affiliation(s)
- Beth India Davenport
- Department of Life SciencesImperial College LondonSouth Kensington CampusLondonUK
| | - Jure Tica
- Department of Life SciencesImperial College LondonSouth Kensington CampusLondonUK
| | - Mark Isalan
- Department of Life SciencesImperial College LondonSouth Kensington CampusLondonUK
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Babosan A, Gaschet M, Muggeo A, Jové T, Skurnik D, Ploy MC, de Champs C, Reffuveille F, Guillard T. A qnrD-Plasmid Promotes Biofilm Formation and Class 1 Integron Gene Cassette Rearrangements in Escherichia coli. Antibiotics (Basel) 2022; 11:antibiotics11060715. [PMID: 35740122 PMCID: PMC9220102 DOI: 10.3390/antibiotics11060715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 05/20/2022] [Accepted: 05/24/2022] [Indexed: 11/17/2022] Open
Abstract
Bacteria within biofilms may be exposed to sub-minimum inhibitory concentrations (sub-MICs) of antibiotics. Cell-to-cell contact within biofilms facilitates horizontal gene transfers and favors induction of the SOS response. Altogether, it participates in the emergence of antibiotic resistance. Aminoglycosides at sub-MICs can induce the SOS response through NO accumulation in E. coli carrying the small plasmid with the quinolone resistance qnrD gene (pDIJ09-518a). In this study, we show that in E. coli pDIJ09-518a, the SOS response triggered by sub-MICs of aminoglycosides has important consequences, promoting genetic rearrangement in class 1 integrons and biofilm formation. We found that the integrase expression was increased in E. coli carrying pDIJ09-518a in the presence of tobramycin, which was not observed for the WT isogenic strain that did not carry the qnrD-plasmid. Moreover, we showed that biofilm production was significantly increased in E. coli WT/pDIJ09-518a compared to the WT strain. However, such a higher production was decreased when the Hmp-NO detoxification pathway was fully functional by overexpressing Hmp. Our results showing that a qnrD-plasmid can promote biofilm formation in E. coli and potentiate the acquisition and spread of resistance determinants for other antibiotics complicate the attempts to counteract antibiotic resistance and prevention of biofilm development even further. We anticipate that our findings emphasize the complex challenges that will impact the decisions about antibiotic stewardship, and other decisions related to retaining antibiotics as effective drugs and the development of new drugs.
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Affiliation(s)
- Anamaria Babosan
- Inserm UMR-S 1250 P3Cell, SFR CAP-Santé, Université de Reims-Champagne-Ardenne, 51100 Reims, France; (A.B.); (A.M.); (C.d.C.)
| | - Margaux Gaschet
- Université de Limoges, Inserm, CHU Limoges, UMR-S 1092, 87032 Limoges, France; (M.G.); (T.J.); (M.-C.P.)
| | - Anaëlle Muggeo
- Inserm UMR-S 1250 P3Cell, SFR CAP-Santé, Université de Reims-Champagne-Ardenne, 51100 Reims, France; (A.B.); (A.M.); (C.d.C.)
- Laboratoire de Bactériologie-Virologie-Hygiène Hospitalière-Parasitologie-Mycologie, CHU Reims, Hôpital Robert Debré, Avenue du Général Koenig, CEDEX, 51092 Reims, France
| | - Thomas Jové
- Université de Limoges, Inserm, CHU Limoges, UMR-S 1092, 87032 Limoges, France; (M.G.); (T.J.); (M.-C.P.)
| | - David Skurnik
- Institut Necker-Enfants Malades, Inserm U1151-Equipe 11, Université Paris Descartes, 75015 Paris, France;
- Laboratoire de Bactériologie, AP-HP, Hôpital Necker-Enfants Malades, 75015 Paris, France
- Division of Infectious Diseases, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Marie-Cécile Ploy
- Université de Limoges, Inserm, CHU Limoges, UMR-S 1092, 87032 Limoges, France; (M.G.); (T.J.); (M.-C.P.)
| | - Christophe de Champs
- Inserm UMR-S 1250 P3Cell, SFR CAP-Santé, Université de Reims-Champagne-Ardenne, 51100 Reims, France; (A.B.); (A.M.); (C.d.C.)
- Laboratoire de Bactériologie-Virologie-Hygiène Hospitalière-Parasitologie-Mycologie, CHU Reims, Hôpital Robert Debré, Avenue du Général Koenig, CEDEX, 51092 Reims, France
| | - Fany Reffuveille
- EA 4691 BiOS, SFR CAP-Santé, Université de Reims Champagne-Ardenne, 51100 Reims, France;
| | - Thomas Guillard
- Inserm UMR-S 1250 P3Cell, SFR CAP-Santé, Université de Reims-Champagne-Ardenne, 51100 Reims, France; (A.B.); (A.M.); (C.d.C.)
- Laboratoire de Bactériologie-Virologie-Hygiène Hospitalière-Parasitologie-Mycologie, CHU Reims, Hôpital Robert Debré, Avenue du Général Koenig, CEDEX, 51092 Reims, France
- Correspondence: ; Tel.: +33-3-26-78-32-10; Fax: +33-3-26-78-41
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