1
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Free TJ, Talley JP, Hyer CD, Miller CJ, Griffitts JS, Bundy BC. Engineering the Signal Resolution of a Paper-Based Cell-Free Glutamine Biosensor with Genetic Engineering, Metabolic Engineering, and Process Optimization. SENSORS (BASEL, SWITZERLAND) 2024; 24:3073. [PMID: 38793927 PMCID: PMC11124800 DOI: 10.3390/s24103073] [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: 04/03/2024] [Revised: 05/03/2024] [Accepted: 05/10/2024] [Indexed: 05/26/2024]
Abstract
Specialized cancer treatments have the potential to exploit glutamine dependence to increase patient survival rates. Glutamine diagnostics capable of tracking a patient's response to treatment would enable a personalized treatment dosage to optimize the tradeoff between treatment success and dangerous side effects. Current clinical glutamine testing requires sophisticated and expensive lab-based tests, which are not broadly available on a frequent, individualized basis. To address the need for a low-cost, portable glutamine diagnostic, this work engineers a cell-free glutamine biosensor to overcome assay background and signal-to-noise limitations evident in previously reported studies. The findings from this work culminate in the development of a shelf-stable, paper-based, colorimetric glutamine test with a high signal strength and a high signal-to-background ratio for dramatically improved signal resolution. While the engineered glutamine test is important progress towards improving the management of cancer and other health conditions, this work also expands the assay development field of the promising cell-free biosensing platform, which can facilitate the low-cost detection of a broad variety of target molecules with high clinical value.
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Affiliation(s)
- Tyler J. Free
- Department of Chemical Engineering, Brigham Young University, Provo, UT 84602, USA
| | - Joseph P. Talley
- Department of Chemical Engineering, Brigham Young University, Provo, UT 84602, USA
| | - Chad D. Hyer
- Department of Chemical Engineering, Brigham Young University, Provo, UT 84602, USA
| | - Catherine J. Miller
- Department of Chemical Engineering, Brigham Young University, Provo, UT 84602, USA
| | - Joel S. Griffitts
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602, USA
| | - Bradley C. Bundy
- Department of Chemical Engineering, Brigham Young University, Provo, UT 84602, USA
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2
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Kalb MJ, Grenfell AW, Jain A, Fenske-Newbart J, Gralnick JA. Comparison of phage-derived recombinases for genetic manipulation of Pseudomonas species. Microbiol Spectr 2023; 11:e0317623. [PMID: 37882574 PMCID: PMC10714826 DOI: 10.1128/spectrum.03176-23] [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: 08/29/2023] [Accepted: 09/09/2023] [Indexed: 10/27/2023] Open
Abstract
IMPORTANCE The Pseudomonas genus contains many members currently being investigated for applications in biodegradation, biopesticides, biocontrol, and synthetic biology. Though several strains have been identified with beneficial properties, chromosomal manipulations to further improve these strains for commercial applications have been limited due to the lack of efficient genetic tools that have been tested across this genus. Here, we test the recombineering efficiencies of five phage-derived recombinases across three biotechnologically relevant Pseudomonas strains: P. putida KT2440, P. protegens Pf-5, and P. protegens CHA0. These results demonstrate a method to generate targeted mutations quickly and efficiently across these strains, ideally introducing a method that can be implemented across the Pseudomonas genus and a strategy that may be applied to develop analogous systems in other nonmodel bacteria.
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Affiliation(s)
- Madison J. Kalb
- BioTechnology Institute and Department of Plant and Microbial Biology, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Andrew W. Grenfell
- BioTechnology Institute and Department of Plant and Microbial Biology, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Abhiney Jain
- BioTechnology Institute and Department of Plant and Microbial Biology, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Jane Fenske-Newbart
- BioTechnology Institute and Department of Plant and Microbial Biology, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Jeffrey A. Gralnick
- BioTechnology Institute and Department of Plant and Microbial Biology, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
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3
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Past, Present, and Future of Genome Modification in Escherichia coli. Microorganisms 2022; 10:microorganisms10091835. [PMID: 36144436 PMCID: PMC9504249 DOI: 10.3390/microorganisms10091835] [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: 08/21/2022] [Revised: 09/05/2022] [Accepted: 09/05/2022] [Indexed: 12/04/2022] Open
Abstract
Escherichia coli K-12 is one of the most well-studied species of bacteria. This species, however, is much more difficult to modify by homologous recombination (HR) than other model microorganisms. Research on HR in E. coli has led to a better understanding of the molecular mechanisms of HR, resulting in technical improvements and rapid progress in genome research, and allowing whole-genome mutagenesis and large-scale genome modifications. Developments using λ Red (exo, bet, and gam) and CRISPR-Cas have made E. coli as amenable to genome modification as other model microorganisms, such as Saccharomyces cerevisiae and Bacillus subtilis. This review describes the history of recombination research in E. coli, as well as improvements in techniques for genome modification by HR. This review also describes the results of large-scale genome modification of E. coli using these technologies, including DNA synthesis and assembly. In addition, this article reviews recent advances in genome modification, considers future directions, and describes problems associated with the creation of cells by design.
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4
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Zeng Y, Hong Y, Azi F, Liu Y, Chen Y, Guo C, Lin D, Wu Z, Chen W, Xu P. Advanced genome-editing technologies enable rapid and large-scale generation of genetic variants for strain engineering and synthetic biology. Curr Opin Microbiol 2022; 69:102175. [PMID: 35809388 DOI: 10.1016/j.mib.2022.102175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 06/05/2022] [Accepted: 06/08/2022] [Indexed: 12/26/2022]
Abstract
Targeted genome editing not only improves our understanding of fundamental rules in life sciences but also affords us versatile toolkits to improve industrially relevant phenotypes in various host cells. In this review, we summarize the recent endeavor to develop efficient genome-editing tools, and emphasize the utility of these tools to generate massive scale of genetic variants. We categorize these tools into traditional recombination-based tools, and more advanced CRISPR as well as RNA-based genome-editing tools. This diverse panel of sophisticated tools has been applied to accelerate strain engineering, upgrade biomanufacturing, and customize biosensing. In parallel with high-throughput phenotyping and AI-based optimization algorithms, we envision that genome-editing technologies will become a driving force to automate and streamline biological engineering, and empower us to address critical challenges in health, environment, energy, and sustainability.
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Affiliation(s)
- Yi Zeng
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, Guangdong 515063, China
| | - Yuxiang Hong
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, Guangdong 515063, China
| | - Fidelis Azi
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, Guangdong 515063, China
| | - Yugeng Liu
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, Guangdong 515063, China
| | - Yousheng Chen
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, Guangdong 515063, China
| | - Chuchu Guo
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, Guangdong 515063, China
| | - Dewei Lin
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, Guangdong 515063, China
| | - Zizhao Wu
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, Guangdong 515063, China
| | - Wenhao Chen
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, Guangdong 515063, China
| | - Peng Xu
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, Guangdong 515063, China; Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion, Guangdong Technion-Israel Institute of Technology, Shantou, Guangdong 515063, China; The Wolfson Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
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5
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Teufel M, Klein CA, Mager M, Sobetzko P. A multifunctional system for genome editing and large-scale interspecies gene transfer. Nat Commun 2022; 13:3430. [PMID: 35701417 PMCID: PMC9198041 DOI: 10.1038/s41467-022-30843-1] [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: 06/15/2021] [Accepted: 05/23/2022] [Indexed: 11/09/2022] Open
Abstract
CRISPR SWAPnDROP extends the limits of genome editing to large-scale in-vivo DNA transfer between bacterial species. Its modular platform approach facilitates species specific adaptation to confer genome editing in various species. In this study, we show the implementation of the CRISPR SWAPnDROP concept for the model organism Escherichia coli, the fast growing Vibrio natriegens and the plant pathogen Dickeya dadantii. We demonstrate the excision, transfer and integration of large chromosomal regions between E. coli, V. natriegens and D. dadantii without size-limiting intermediate DNA extraction. CRISPR SWAPnDROP also provides common genome editing approaches comprising scarless, marker-free, iterative and parallel insertions and deletions. The modular character facilitates DNA library applications, and recycling of standardized parts. Its multi-color scarless co-selection system significantly improves editing efficiency and provides visual quality controls throughout the assembly and editing process.
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Affiliation(s)
- Marc Teufel
- Philipps Universität Marburg, Synthetic Microbiology Center Marburg (SYNMIKRO), Marburg, 35043, Germany
| | - Carlo A Klein
- Philipps Universität Marburg, Synthetic Microbiology Center Marburg (SYNMIKRO), Marburg, 35043, Germany
| | - Maurice Mager
- Philipps Universität Marburg, Synthetic Microbiology Center Marburg (SYNMIKRO), Marburg, 35043, Germany
| | - Patrick Sobetzko
- Philipps Universität Marburg, Synthetic Microbiology Center Marburg (SYNMIKRO), Marburg, 35043, Germany.
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6
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Tong Y, Jørgensen TS, Whitford CM, Weber T, Lee SY. A versatile genetic engineering toolkit for E. coli based on CRISPR-prime editing. Nat Commun 2021; 12:5206. [PMID: 34471126 PMCID: PMC8410854 DOI: 10.1038/s41467-021-25541-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 08/16/2021] [Indexed: 01/04/2023] Open
Abstract
CRISPR base editing is a powerful method to engineer bacterial genomes. However, it restricts editing to single-nucleotide substitutions. Here, to address this challenge, we adapt a CRISPR-Prime Editing-based, DSB-free, versatile, and single-nucleotide resolution genetic manipulation toolkit for prokaryotes. It can introduce substitutions, deletions, insertions, and the combination thereof, both in plasmids and the chromosome of E. coli with high fidelity. Notably, under optimal conditions, the efficiency of 1-bp deletions reach up to 40%. Moreover, deletions of up to 97 bp and insertions up to 33 bp were successful with the toolkit in E. coli, however, efficiencies dropped sharply with increased fragment sizes. With a second guide RNA, our toolkit can achieve multiplexed editing albeit with low efficiency. Here we report not only a useful addition to the genome engineering arsenal for E. coli, but also a potential basis for the development of similar toolkits for other bacteria.
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Affiliation(s)
- Yaojun Tong
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University (SJTU), Shanghai, China.
| | - Tue S Jørgensen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Christopher M Whitford
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Tilmann Weber
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.
| | - Sang Yup Lee
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.
- Department of Chemical and Biomolecular Engineering, BioProcess Engineering Research Center, BioInformatics Research Center, Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
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7
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Racharaks R, Arnold W, Peccia J. Development of CRISPR-Cas9 knock-in tools for free fatty acid production using the fast-growing cyanobacterial strain Synechococcus elongatus UTEX 2973. J Microbiol Methods 2021; 189:106315. [PMID: 34454980 DOI: 10.1016/j.mimet.2021.106315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/23/2021] [Accepted: 08/23/2021] [Indexed: 12/26/2022]
Abstract
Synechococcus elongatus UTEX 2973 has one of the fastest measured doubling time of cyanobacteria making it an important candidate for metabolic engineering. Traditional genetic engineering methods, which rely on homologous recombination, however, are inefficient, labor-intensive, and time-consuming due to the oligoploidy or polyploidy nature of cyanobacteria and the reliance on unique antibiotic resistance markers. CRISPR-Cas9 has emerged as an effective and versatile editing platform in a wide variety of organisms, but its application for cyanobacterial engineering is limited by the inherent toxicity of Cas9 resulting in poor transformation efficiencies. Here, we demonstrated that a single-plasmid CRISPR-Cas9 system, pCRISPOmyces-2, can effectively knock-in a truncated thioesterase gene from Escherichia coli to generate free fatty acid (FFA) producing mutants of Syn2973. To do so, three parameters were evaluated on the effect of generating recipient colonies after conjugation with pCRISPOmyces-2-based plasmids: 1) a modified conjugation protocol termed streaked conjugation, 2) the deletion of the gene encoding RecJ exonuclease, and 3) single guide RNA (sgRNA) sequence. With the use of the streaked conjugation protocol and a ΔrecJ mutant strain of Syn2973, the conjugation efficiency for the pCRISPomyces-2 plasmid could be improved by 750-fold over the wildtype (WT) for a conjugation efficiency of 2.0 × 10-6 transconjugants/recipient cell. While deletion of the RecJ exonuclease alone increased the conjugation efficiency by 150-fold over the WT, FFA generation was impaired in FFA-producing mutants with the ΔrecJ background, and the large number of poor FFA-producing isolates indicated the potential increase in spontaneous mutation rates. The sgRNA sequence was found to be critical in achieving the desired CRISPR-Cas9-mediated knock-in mutation as the sgRNA impacts conjugation efficiency, likelihood of homogenous recombinants, and free fatty acid production in engineered strains.
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Affiliation(s)
- Ratanachat Racharaks
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, USA
| | - Wyatt Arnold
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, USA
| | - Jordan Peccia
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, USA.
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8
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Schubert MG, Goodman DB, Wannier TM, Kaur D, Farzadfard F, Lu TK, Shipman SL, Church GM. High-throughput functional variant screens via in vivo production of single-stranded DNA. Proc Natl Acad Sci U S A 2021; 118:e2018181118. [PMID: 33906944 PMCID: PMC8106316 DOI: 10.1073/pnas.2018181118] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Creating and characterizing individual genetic variants remains limited in scale, compared to the tremendous variation both existing in nature and envisioned by genome engineers. Here we introduce retron library recombineering (RLR), a methodology for high-throughput functional screens that surpasses the scale and specificity of CRISPR-Cas methods. We use the targeted reverse-transcription activity of retrons to produce single-stranded DNA (ssDNA) in vivo, incorporating edits at >90% efficiency and enabling multiplexed applications. RLR simultaneously introduces many genomic variants, producing pooled and barcoded variant libraries addressable by targeted deep sequencing. We use RLR for pooled phenotyping of synthesized antibiotic resistance alleles, demonstrating quantitative measurement of relative growth rates. We also perform RLR using the sheared genomic DNA of an evolved bacterium, experimentally querying millions of sequences for causal variants, demonstrating that RLR is uniquely suited to utilize large pools of natural variation. Using ssDNA produced in vivo for pooled experiments presents avenues for exploring variation across the genome.
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Affiliation(s)
- Max G Schubert
- Department of Genetics, Harvard Medical School, Boston, MA 02115;
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115
| | - Daniel B Goodman
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143
| | | | - Divjot Kaur
- Department of Zoology, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Fahim Farzadfard
- Research Laboratory of Electronics, Massachussetts Institute of Technology, Cambridge, MA 02139
| | - Timothy K Lu
- Research Laboratory of Electronics, Massachussetts Institute of Technology, Cambridge, MA 02139
| | - Seth L Shipman
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA 94158
| | - George M Church
- Department of Genetics, Harvard Medical School, Boston, MA 02115
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115
- Research Laboratory of Electronics, Massachussetts Institute of Technology, Cambridge, MA 02139
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9
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Wannier TM, Nyerges A, Kuchwara HM, Czikkely M, Balogh D, Filsinger GT, Borders NC, Gregg CJ, Lajoie MJ, Rios X, Pál C, Church GM. Improved bacterial recombineering by parallelized protein discovery. Proc Natl Acad Sci U S A 2020; 117:13689-13698. [PMID: 32467157 PMCID: PMC7306799 DOI: 10.1073/pnas.2001588117] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Exploiting bacteriophage-derived homologous recombination processes has enabled precise, multiplex editing of microbial genomes and the construction of billions of customized genetic variants in a single day. The techniques that enable this, multiplex automated genome engineering (MAGE) and directed evolution with random genomic mutations (DIvERGE), are however, currently limited to a handful of microorganisms for which single-stranded DNA-annealing proteins (SSAPs) that promote efficient recombineering have been identified. Thus, to enable genome-scale engineering in new hosts, efficient SSAPs must first be found. Here we introduce a high-throughput method for SSAP discovery that we call "serial enrichment for efficient recombineering" (SEER). By performing SEER in Escherichia coli to screen hundreds of putative SSAPs, we identify highly active variants PapRecT and CspRecT. CspRecT increases the efficiency of single-locus editing to as high as 50% and improves multiplex editing by 5- to 10-fold in E. coli, while PapRecT enables efficient recombineering in Pseudomonas aeruginosa, a concerning human pathogen. CspRecT and PapRecT are also active in other, clinically and biotechnologically relevant enterobacteria. We envision that the deployment of SEER in new species will pave the way toward pooled interrogation of genotype-to-phenotype relationships in previously intractable bacteria.
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Affiliation(s)
| | - Akos Nyerges
- Department of Genetics, Harvard Medical School, Boston, MA 02115
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged HU-6726, Hungary
| | | | - Márton Czikkely
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged HU-6726, Hungary
| | - Dávid Balogh
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged HU-6726, Hungary
| | | | | | | | - Marc J Lajoie
- Department of Genetics, Harvard Medical School, Boston, MA 02115
| | - Xavier Rios
- Department of Genetics, Harvard Medical School, Boston, MA 02115
| | - Csaba Pál
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged HU-6726, Hungary
| | - George M Church
- Department of Genetics, Harvard Medical School, Boston, MA 02115;
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10
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Egbert RG, Rishi HS, Adler BA, McCormick DM, Toro E, Gill RT, Arkin AP. A versatile platform strain for high-fidelity multiplex genome editing. Nucleic Acids Res 2019; 47:3244-3256. [PMID: 30788501 PMCID: PMC6451135 DOI: 10.1093/nar/gkz085] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 12/13/2018] [Accepted: 02/09/2019] [Indexed: 12/01/2022] Open
Abstract
Precision genome editing accelerates the discovery of the genetic determinants of phenotype and the engineering of novel behaviors in organisms. Advances in DNA synthesis and recombineering have enabled high-throughput engineering of genetic circuits and biosynthetic pathways via directed mutagenesis of bacterial chromosomes. However, the highest recombination efficiencies have to date been reported in persistent mutator strains, which suffer from reduced genomic fidelity. The absence of inducible transcriptional regulators in these strains also prevents concurrent control of genome engineering tools and engineered functions. Here, we introduce a new recombineering platform strain, BioDesignER, which incorporates (i) a refactored λ-Red recombination system that reduces toxicity and accelerates multi-cycle recombination, (ii) genetic modifications that boost recombination efficiency, and (iii) four independent inducible regulators to control engineered functions. These modifications resulted in single-cycle recombineering efficiencies of up to 25% with a 7-fold increase in recombineering fidelity compared to the widely used recombineering strain EcNR2. To facilitate genome engineering in BioDesignER, we have curated eight context-neutral genomic loci, termed Safe Sites, for stable gene expression and consistent recombination efficiency. BioDesignER is a platform to develop and optimize engineered cellular functions and can serve as a model to implement comparable recombination and regulatory systems in other bacteria.
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Affiliation(s)
- Robert G Egbert
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Harneet S Rishi
- Biophysics Graduate Group, University of California - Berkeley, Berkeley, CA 94720, USA.,Designated Emphasis Program in Computational and Genomic Biology, University of California - Berkeley, Berkeley, CA 94720, USA
| | - Benjamin A Adler
- UC Berkeley-UCSF Graduate Program in Bioengineering, University of California - Berkeley, Berkeley, CA 94720, USA.,Department of Bioengineering, University of California - Berkeley, Berkeley, CA 94720, USA
| | - Dylan M McCormick
- Department of Bioengineering, University of California - Berkeley, Berkeley, CA 94720, USA
| | - Esteban Toro
- Department of Bioengineering, University of California - Berkeley, Berkeley, CA 94720, USA
| | - Ryan T Gill
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Adam P Arkin
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.,Department of Bioengineering, University of California - Berkeley, Berkeley, CA 94720, USA
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11
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Caldwell BJ, Bell CE. Structure and mechanism of the Red recombination system of bacteriophage λ. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 147:33-46. [PMID: 30904699 DOI: 10.1016/j.pbiomolbio.2019.03.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 03/05/2019] [Accepted: 03/15/2019] [Indexed: 01/27/2023]
Abstract
While much of this volume focuses on mammalian DNA repair systems that are directly involved in genome stability and cancer, it is important to still be mindful of model systems from prokaryotes. Herein we review the Red recombination system of bacteriophage λ, which consists of an exonuclease for resecting dsDNA ends, and a single-strand annealing protein (SSAP) for binding the resulting 3'-overhang and annealing it to a complementary strand. The genetics and biochemistry of Red have been studied for over 50 years, in work that has laid much of the foundation for understanding DNA recombination in higher eukaryotes. In fact, the Red exonuclease (λ exo) is homologous to Dna2, a nuclease involved in DNA end-resection in eukaryotes, and the Red annealing protein (Redβ) is homologous to Rad52, the primary SSAP in eukaryotes. While eukaryotic recombination involves an elaborate network of proteins that is still being unraveled, the phage systems are comparatively simple and streamlined, yet still encompass the fundamental features of recombination, namely DNA end-resection, homologous pairing (annealing), and a coupling between them. Moreover, the Red system has been exploited in powerful methods for bacterial genome engineering that are important for functional genomics and systems biology. However, several mechanistic aspects of Red, particularly the action of the annealing protein, remain poorly understood. This review will focus on the proteins of the Red recombination system, with particular attention to structural and mechanistic aspects, and how the lessons learned can be applied to eukaryotic systems.
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Affiliation(s)
- Brian J Caldwell
- Ohio State Biochemistry Program, The Ohio State University, 484 West 12th Avenue, Columbus, OH, 43210, USA; Department of Biological Chemistry and Pharmacology, The Ohio State University, 1060 Carmack Road, Columbus, OH, 43210, USA
| | - Charles E Bell
- Ohio State Biochemistry Program, The Ohio State University, 484 West 12th Avenue, Columbus, OH, 43210, USA; Department of Biological Chemistry and Pharmacology, The Ohio State University, 1060 Carmack Road, Columbus, OH, 43210, USA; Department of Chemistry and Biochemistry, 484 West 12th Avenue, 1060 Carmack Road, Columbus, OH, 43210, USA.
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12
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Coupling ssDNA recombineering with CRISPR-Cas9 for Escherichia coli DnaG mutations. Appl Microbiol Biotechnol 2019; 103:3559-3570. [DOI: 10.1007/s00253-019-09744-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 02/18/2019] [Accepted: 03/06/2019] [Indexed: 10/27/2022]
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13
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Yang S, Wang Y, Wei C, Liu Q, Jin X, Du G, Chen J, Kang Z. A new sRNA-mediated posttranscriptional regulation system for Bacillus subtilis. Biotechnol Bioeng 2018; 115:2986-2995. [PMID: 30199104 DOI: 10.1002/bit.26833] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 08/27/2018] [Accepted: 09/05/2018] [Indexed: 01/01/2023]
Abstract
Many genetic tools for gene regulation have been developed during the past decades. Some of them edit genomic DNA, such as nucleotides deletions and insertions, while the others interfere with the gene transcriptions or messenger RNA translation. Here, we report a posttranscriptional regulation tool which is termed "Modulation via the small RNA (sRNA)-dependent operation system: MS-DOS" by engineering the type I toxin-antitoxin system in Bacillus subtilis. MS-DOS depends simply on insertion of an operation region (OPR; partial toxin-encoding region) downstream of a genomic open reading frame of interest and overexpression of the coupling antitoxin sRNA from a plasmid. Pairing between the OPR and the sRNA will trigger the RNAse degradation of the transcripts of selected genes. MS-DOS allows for the quantitative, specific, and reversible knockdown of single or multiple genomic genes in B. subtilis. We also showed that the truncated antitoxin SR4 with 53 nt length is sufficient to repress gene expression. Superior to other existing RNA based interfering systems, MS-DOS allows simultaneous knockdown of multiple genes with effortless expression of a single antitoxin RNA. This sRNA-guided repression system will further enrich the gene regulation tools and expand the gene regulation flexibility.
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Affiliation(s)
- Sen Yang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Yang Wang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Chaobao Wei
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Qingtao Liu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Xuerong Jin
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Guocheng Du
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Jian Chen
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Zhen Kang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
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14
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Zebec Z, Scrutton NS. Genome Editing for the Production of Natural Products inEscherichia coli. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/adbi.201800056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Ziga Zebec
- Manchester Institute of Biotechnology and School of Chemistry; The University of Manchester; Manchester M1 7DN UK
| | - Nigel S. Scrutton
- Manchester Institute of Biotechnology and School of Chemistry; The University of Manchester; Manchester M1 7DN UK
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15
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Valero-Rello A, López-Sanz M, Quevedo-Olmos A, Sorokin A, Ayora S. Molecular Mechanisms That Contribute to Horizontal Transfer of Plasmids by the Bacteriophage SPP1. Front Microbiol 2017; 8:1816. [PMID: 29018417 PMCID: PMC5615212 DOI: 10.3389/fmicb.2017.01816] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 09/06/2017] [Indexed: 01/02/2023] Open
Abstract
Natural transformation and viral-mediated transduction are the main avenues of horizontal gene transfer in Firmicutes. Bacillus subtilis SPP1 is a generalized transducing bacteriophage. Using this lytic phage as a model, we have analyzed how viral replication and recombination systems contribute to the transfer of plasmid-borne antibiotic resistances. Phage SPP1 DNA replication relies on essential phage-encoded replisome organizer (G38P), helicase loader (G39P), hexameric replicative helicase (G40P), recombinase (G35P) and in less extent on the partially dispensable 5′→3′ exonuclease (G34.1P), the single-stranded DNA binding protein (G36P) and the Holliday junction resolvase (G44P). Correspondingly, the accumulation of linear concatemeric plasmid DNA, and the formation of transducing particles were blocked in the absence of G35P, G38P, G39P, and G40P, greatly reduced in the G34.1P, G36P mutants, and slightly reduced in G44P mutants. In contrast, establishment of injected linear plasmid DNA in the recipient host was independent of viral-encoded functions. DNA homology between SPP1 and the plasmid, rather than a viral packaging signal, enhanced the accumulation of packagable plasmid DNA. The transfer efficiency was also dependent on plasmid copy number, and rolling-circle plasmids were encapsidated at higher frequencies than theta-type replicating plasmids.
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Affiliation(s)
- Ana Valero-Rello
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones CientíficasMadrid, Spain.,Micalis Institute, INRA, AgroParisTech, Universite Paris-SaclayJouy-en-Josas, France
| | - María López-Sanz
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones CientíficasMadrid, Spain
| | - Alvaro Quevedo-Olmos
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones CientíficasMadrid, Spain
| | - Alexei Sorokin
- Micalis Institute, INRA, AgroParisTech, Universite Paris-SaclayJouy-en-Josas, France
| | - Silvia Ayora
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones CientíficasMadrid, Spain
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16
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Josephs EA, Marszalek PE. A 'Semi-Protected Oligonucleotide Recombination' Assay for DNA Mismatch Repair in vivo Suggests Different Modes of Repair for Lagging Strand Mismatches. Nucleic Acids Res 2017; 45:e63. [PMID: 28053122 PMCID: PMC5416779 DOI: 10.1093/nar/gkw1339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 12/20/2016] [Indexed: 12/18/2022] Open
Abstract
In Escherichia coli, a DNA mismatch repair (MMR) pathway corrects errors that occur during DNA replication by coordinating the excision and re-synthesis of a long tract of the newly-replicated DNA between an epigenetic signal (a hemi-methylated d(GATC) site or a single-stranded nick) and the replication error after the error is identified by protein MutS. Recent observations suggest that this 'long-patch repair' between these sites is coordinated in the same direction of replication by the replisome. Here, we have developed a new assay that uniquely allows us to introduce targeted 'mismatches' directly into the replication fork via oligonucleotide recombination, examine the directionality of MMR, and quantify the nucleotide-dependence, sequence context-dependence, and strand-dependence of their repair in vivo-something otherwise nearly impossible to achieve. We find that repair of genomic lagging strand mismatches occurs bi-directionally in E. coli and that, while all MutS-recognized mismatches had been thought to be repaired in a consistent manner, the directional bias of repair and the effects of mutations in MutS are dependent on the molecular species of the mismatch. Because oligonucleotide recombination is routinely performed in both prokaryotic and eukaryotic cells, we expect this assay will be broadly applicable for investigating mechanisms of MMR in vivo.
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Affiliation(s)
- Eric A Josephs
- Department of Mechanical Engineering and Materials Science, Edmund T. Pratt, Jr. School of Engineering, Duke University, Durham, NC, USA
| | - Piotr E Marszalek
- Department of Mechanical Engineering and Materials Science, Edmund T. Pratt, Jr. School of Engineering, Duke University, Durham, NC, USA
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17
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Genome reprogramming for synthetic biology. Front Chem Sci Eng 2017. [DOI: 10.1007/s11705-017-1618-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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18
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Subramaniam S, Erler A, Fu J, Kranz A, Tang J, Gopalswamy M, Ramakrishnan S, Keller A, Grundmeier G, Müller D, Sattler M, Stewart AF. DNA annealing by Redβ is insufficient for homologous recombination and the additional requirements involve intra- and inter-molecular interactions. Sci Rep 2016; 6:34525. [PMID: 27708411 PMCID: PMC5052646 DOI: 10.1038/srep34525] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 08/15/2016] [Indexed: 01/09/2023] Open
Abstract
Single strand annealing proteins (SSAPs) like Redβ initiate homologous recombination by annealing complementary DNA strands. We show that C-terminally truncated Redβ, whilst still able to promote annealing and nucleoprotein filament formation, is unable to mediate homologous recombination. Mutations of the C-terminal domain were evaluated using both single- and double stranded (ss and ds) substrates in recombination assays. Mutations of critical amino acids affected either dsDNA recombination or both ssDNA and dsDNA recombination indicating two separable functions, one of which is critical for dsDNA recombination and the second for recombination per se. As evaluated by co-immunoprecipitation experiments, the dsDNA recombination function relates to the Redα-Redβ protein-protein interaction, which requires not only contacts in the C-terminal domain but also a region near the N-terminus. Because the nucleoprotein filament formed with C-terminally truncated Redβ has altered properties, the second C-terminal function could be due to an interaction required for functional filaments. Alternatively the second C-terminal function could indicate a requirement for a Redβ-host factor interaction. These data further advance the model for Red recombination and the proposition that Redβ and RAD52 SSAPs share ancestral and mechanistic roots.
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Affiliation(s)
| | - Axel Erler
- Genomics, Biotechnology Center, TU Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Jun Fu
- Genomics, Biotechnology Center, TU Dresden, Tatzberg 47/49, 01307 Dresden, Germany.,Shandong University-Helmholtz Joint Institute of Biotechnology, State Key Laboratory of Microbial Technology, Shandong University, Shanda Nanlu 27, 250100 Jinan, People's Republic of China
| | - Andrea Kranz
- Genomics, Biotechnology Center, TU Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Jing Tang
- Genomics, Biotechnology Center, TU Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Mohanraj Gopalswamy
- Institute of Structural Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany and Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry, Technische Universität München, Lichtenbergstr.4, 85747 Garching, Germany
| | - Saminathan Ramakrishnan
- Technical and Macromolecular Chemistry, University of Paderborn, Warburger Str. 100 33098 Paderborn, Germany
| | - Adrian Keller
- Technical and Macromolecular Chemistry, University of Paderborn, Warburger Str. 100 33098 Paderborn, Germany
| | - Guido Grundmeier
- Technical and Macromolecular Chemistry, University of Paderborn, Warburger Str. 100 33098 Paderborn, Germany
| | - Daniel Müller
- Department of Biosystems Science and Engineering (D-BSSE), ETH Zürich, Mattenstraße 26, 4058 Basel, Switzerland
| | - Michael Sattler
- Institute of Structural Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany and Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry, Technische Universität München, Lichtenbergstr.4, 85747 Garching, Germany
| | - A Francis Stewart
- Genomics, Biotechnology Center, TU Dresden, Tatzberg 47/49, 01307 Dresden, Germany
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19
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Emergent rules for codon choice elucidated by editing rare arginine codons in Escherichia coli. Proc Natl Acad Sci U S A 2016; 113:E5588-97. [PMID: 27601680 DOI: 10.1073/pnas.1605856113] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The degeneracy of the genetic code allows nucleic acids to encode amino acid identity as well as noncoding information for gene regulation and genome maintenance. The rare arginine codons AGA and AGG (AGR) present a case study in codon choice, with AGRs encoding important transcriptional and translational properties distinct from the other synonymous alternatives (CGN). We created a strain of Escherichia coli with all 123 instances of AGR codons removed from all essential genes. We readily replaced 110 AGR codons with the synonymous CGU codons, but the remaining 13 "recalcitrant" AGRs required diversification to identify viable alternatives. Successful replacement codons tended to conserve local ribosomal binding site-like motifs and local mRNA secondary structure, sometimes at the expense of amino acid identity. Based on these observations, we empirically defined metrics for a multidimensional "safe replacement zone" (SRZ) within which alternative codons are more likely to be viable. To evaluate synonymous and nonsynonymous alternatives to essential AGRs further, we implemented a CRISPR/Cas9-based method to deplete a diversified population of a wild-type allele, allowing us to evaluate exhaustively the fitness impact of all 64 codon alternatives. Using this method, we confirmed the relevance of the SRZ by tracking codon fitness over time in 14 different genes, finding that codons that fall outside the SRZ are rapidly depleted from a growing population. Our unbiased and systematic strategy for identifying unpredicted design flaws in synthetic genomes and for elucidating rules governing codon choice will be crucial for designing genomes exhibiting radically altered genetic codes.
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20
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Abstract
The bacteriophage λ Red homologous recombination system has been studied over the past 50 years as a model system to define the mechanistic details of how organisms exchange DNA segments that share extended regions of homology. The λ Red system proved useful as a system to study because recombinants could be easily generated by co-infection of genetically marked phages. What emerged from these studies was the recognition that replication of phage DNA was required for substantial Red-promoted recombination in vivo, and the critical role that double-stranded DNA ends play in allowing the Red proteins access to the phage DNA chromosomes. In the past 16 years, however, the λ Red recombination system has gained a new notoriety. When expressed independently of other λ functions, the Red system is able to promote recombination of linear DNA containing limited regions of homology (∼50 bp) with the Escherichia coli chromosome, a process known as recombineering. This review explains how the Red system works during a phage infection, and how it is utilized to make chromosomal modifications of E. coli with such efficiency that it changed the nature and number of genetic manipulations possible, leading to advances in bacterial genomics, metabolic engineering, and eukaryotic genetics.
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Affiliation(s)
- Kenan C Murphy
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605
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21
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Karas BJ, Suzuki Y, Weyman PD. Strategies for cloning and manipulating natural and synthetic chromosomes. Chromosome Res 2015; 23:57-68. [PMID: 25596826 DOI: 10.1007/s10577-014-9455-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Advances in synthetic biology methods to assemble and edit DNA are enabling genome engineering at a previously impracticable scale and scope. The synthesis of the Mycoplasma mycoides genome followed by its transplantation to convert a related cell into M. mycoides has transformed strain engineering. This approach exemplifies the combination of newly emerging chromosome-scale genome editing strategies that can be defined in three main steps: (1) chromosome acquisition into a microbial engineering platform, (2) alteration and improvement of the acquired chromosome, and (3) installation of the modified chromosome into the original or alternative organism. In this review, we outline recent progress in methods for acquiring chromosomes and chromosome-scale DNA molecules in the workhorse organisms Bacillus subtilis, Escherichia coli, and Saccharomyces cerevisiae. We present overviews of important genetic strategies and tools for each of the three organisms, point out their respective strengths and weaknesses, and highlight how the host systems can be used in combination to facilitate chromosome assembly or engineering. Finally, we highlight efforts for the installation of the cloned/altered chromosomes or fragments into the target organism and present remaining challenges in expanding this powerful experimental approach to a wider range of target organisms.
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Affiliation(s)
- Bogumil J Karas
- Synthetic Biology and Bioenergy Group, J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, CA, 92037, USA
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22
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Seven gene deletions in seven days: Fast generation of Escherichia coli strains tolerant to acetate and osmotic stress. Sci Rep 2015; 5:17874. [PMID: 26643270 PMCID: PMC4672327 DOI: 10.1038/srep17874] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 11/06/2015] [Indexed: 11/08/2022] Open
Abstract
Generation of multiple genomic alterations is currently a time consuming process. Here, a method was established that enables highly efficient and simultaneous deletion of multiple genes in Escherichia coli. A temperature sensitive plasmid containing arabinose inducible lambda Red recombineering genes and a rhamnose inducible flippase recombinase was constructed to facilitate fast marker-free deletions. To further speed up the procedure, we integrated the arabinose inducible lambda Red recombineering genes and the rhamnose inducible FLP into the genome of E. coli K-12 MG1655. This system enables growth at 37 °C, thereby facilitating removal of integrated antibiotic cassettes and deletion of additional genes in the same day. Phosphorothioated primers were demonstrated to enable simultaneous deletions during one round of electroporation. Utilizing these methods, we constructed strains in which four to seven genes were deleted in E. coli W and E. coli K-12. The growth rate of an E. coli K-12 quintuple deletion strain was significantly improved in the presence of high concentrations of acetate and NaCl. In conclusion, we have generated a method that enables efficient and simultaneous deletion of multiple genes in several E. coli variants. The method enables deletion of up to seven genes in as little as seven days.
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23
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Bongers M, Chrysanthopoulos PK, Behrendorff JBYH, Hodson MP, Vickers CE, Nielsen LK. Systems analysis of methylerythritol-phosphate pathway flux in E. coli: insights into the role of oxidative stress and the validity of lycopene as an isoprenoid reporter metabolite. Microb Cell Fact 2015; 14:193. [PMID: 26610700 PMCID: PMC4662018 DOI: 10.1186/s12934-015-0381-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 11/11/2015] [Indexed: 12/13/2022] Open
Abstract
Background High-throughput screening methods assume that the output measured is representative of changes in metabolic flux toward the desired product and is not affected by secondary phenotypes. However, metabolic engineering can result in unintended phenotypes that may go unnoticed in initial screening. The red pigment lycopene, a carotenoid with antioxidant properties, has been used as a reporter of isoprenoid pathway flux in metabolic engineering for over a decade. Lycopene production is known to vary between wild-type Escherichia coli hosts, but the reasons behind this variation have never been fully elucidated. Results In an examination of six E. coli strains we observed that strains also differ in their capacity for increased lycopene production in response to metabolic engineering. A combination of genetic complementation, quantitative SWATH proteomics, and biochemical analysis in closely-related strains was used to examine the mechanistic reasons for variation in lycopene accumulation. This study revealed that rpoS, a gene previously identified in lycopene production association studies, exerts its effect on lycopene accumulation not through modulation of pathway flux, but through alteration of cellular oxidative status. Specifically, absence of rpoS results in increased accumulation of reactive oxygen species during late log and stationary phases. This change in cellular redox has no effect on isoprenoid pathway flux, despite the presence of oxygen-sensitive iron-sulphur cluster enzymes and the heavy redox requirements of the methylerythritol phosphate pathway. Instead, decreased cellular lycopene in the ΔrpoS strain is caused by degradation of lycopene in the presence of excess reactive oxygen species. Conclusions Our results demonstrate that lycopene is not a reliable indicator of isoprenoid pathway flux in the presence of oxidative stress, and suggest that caution should be exercised when using lycopene as a screening tool in genome-wide metabolic engineering studies. More extensive use of systems biology for strain analysis will help elucidate such unpredictable side-effects in metabolic engineering projects. Electronic supplementary material The online version of this article (doi:10.1186/s12934-015-0381-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mareike Bongers
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St. Lucia, QLD, 4072, Australia.
| | - Panagiotis K Chrysanthopoulos
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St. Lucia, QLD, 4072, Australia. .,Metabolomics Australia (Queensland Node), The University of Queensland, St. Lucia, QLD, 4072, Australia.
| | - James B Y H Behrendorff
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St. Lucia, QLD, 4072, Australia.
| | - Mark P Hodson
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St. Lucia, QLD, 4072, Australia. .,Metabolomics Australia (Queensland Node), The University of Queensland, St. Lucia, QLD, 4072, Australia.
| | - Claudia E Vickers
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St. Lucia, QLD, 4072, Australia.
| | - Lars K Nielsen
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St. Lucia, QLD, 4072, Australia.
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24
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Pines G, Freed EF, Winkler JD, Gill RT. Bacterial Recombineering: Genome Engineering via Phage-Based Homologous Recombination. ACS Synth Biol 2015; 4:1176-85. [PMID: 25856528 DOI: 10.1021/acssynbio.5b00009] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The ability to specifically modify bacterial genomes in a precise and efficient manner is highly desired in various fields, ranging from molecular genetics to metabolic engineering and synthetic biology. Much has changed from the initial realization that phage-derived genes may be employed for such tasks to today, where recombineering enables complex genetic edits within a genome or a population. Here, we review the major developments leading to recombineering becoming the method of choice for in situ bacterial genome editing while highlighting the various applications of recombineering in pushing the boundaries of synthetic biology. We also present the current understanding of the mechanism of recombineering. Finally, we discuss in detail issues surrounding recombineering efficiency and future directions for recombineering-based genome editing.
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Affiliation(s)
- Gur Pines
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Emily F. Freed
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - James D. Winkler
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Ryan T. Gill
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
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25
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The no-SCAR (Scarless Cas9 Assisted Recombineering) system for genome editing in Escherichia coli. Sci Rep 2015; 5:15096. [PMID: 26463009 PMCID: PMC4604488 DOI: 10.1038/srep15096] [Citation(s) in RCA: 147] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 09/15/2015] [Indexed: 02/02/2023] Open
Abstract
Genome engineering methods in E. coli allow for easy to perform manipulations of the chromosome in vivo with the assistance of the λ-Red recombinase system. These methods generally rely on the insertion of an antibiotic resistance cassette followed by removal of the same cassette, resulting in a two-step procedure for genomic manipulations. Here we describe a method and plasmid system that can edit the genome of E. coli without chromosomal markers. This system, known as Scarless Cas9 Assisted Recombineering (no-SCAR), uses λ-Red to facilitate genomic integration of donor DNA and double stranded DNA cleavage by Cas9 to counterselect against wild-type cells. We show that point mutations, gene deletions, and short sequence insertions were efficiently performed in several genomic loci in a single-step with regards to the chromosome and did not leave behind scar sites. The single-guide RNA encoding plasmid can be easily cured due to its temperature sensitive origin of replication, allowing for iterative chromosomal manipulations of the same strain, as is often required in metabolic engineering. In addition, we demonstrate the ability to efficiently cure the second plasmid in the system by targeting with Cas9, leaving the cells plasmid-free.
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26
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Bao Z, Cobb RE, Zhao H. Accelerated genome engineering through multiplexing. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2015; 8:5-21. [PMID: 26394307 DOI: 10.1002/wsbm.1319] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 08/19/2015] [Accepted: 08/19/2015] [Indexed: 12/27/2022]
Abstract
Throughout the biological sciences, the past 15 years have seen a push toward the analysis and engineering of biological systems at the organism level. Given the complexity of even the simplest organisms, though, to elicit a phenotype of interest often requires genotypic manipulation of several loci. By traditional means, sequential editing of genomic targets requires a significant investment of time and labor, as the desired editing event typically occurs at a very low frequency against an overwhelming unedited background. In recent years, the development of a suite of new techniques has greatly increased editing efficiency, opening up the possibility for multiple editing events to occur in parallel. Termed as multiplexed genome engineering, this approach to genome editing has greatly expanded the scope of possible genome manipulations in diverse hosts, ranging from bacteria to human cells. The enabling technologies for multiplexed genome engineering include oligonucleotide-based and nuclease-based methodologies, and their application has led to the great breadth of successful examples described in this review. While many technical challenges remain, there also exists a multiplicity of opportunities in this rapidly expanding field.
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Affiliation(s)
- Zehua Bao
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ryan E Cobb
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Huimin Zhao
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Chemistry, Department of Bioengineering, and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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27
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Reddy TR, Kelsall EJ, Fevat LMS, Munson SE, Cowley SM. Differential requirements of singleplex and multiplex recombineering of large DNA constructs. PLoS One 2015; 10:e0125533. [PMID: 25954970 PMCID: PMC4425527 DOI: 10.1371/journal.pone.0125533] [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: 12/02/2014] [Accepted: 03/16/2015] [Indexed: 11/18/2022] Open
Abstract
Recombineering is an in vivo genetic engineering technique involving homologous recombination mediated by phage recombination proteins. The use of recombineering methodology is not limited by size and sequence constraints and therefore has enabled the streamlined construction of bacterial strains and multi-component plasmids. Recombineering applications commonly utilize singleplex strategies and the parameters are extensively tested. However, singleplex recombineering is not suitable for the modification of several loci in genome recoding and strain engineering exercises, which requires a multiplex recombineering design. Defining the main parameters affecting multiplex efficiency especially the insertion of multiple large genes is necessary to enable efficient large-scale modification of the genome. Here, we have tested different recombineering operational parameters of the lambda phage Red recombination system and compared singleplex and multiplex recombineering of large gene sized DNA cassettes. We have found that optimal multiplex recombination required long homology lengths in excess of 120 bp. However, efficient multiplexing was possible with only 60 bp of homology. Multiplex recombination was more limited by lower amounts of DNA than singleplex recombineering and was greatly enhanced by use of phosphorothioate protection of DNA. Exploring the mechanism of multiplexing revealed that efficient recombination required co-selection of an antibiotic marker and the presence of all three Red proteins. Building on these results, we substantially increased multiplex efficiency using an ExoVII deletion strain. Our findings elucidate key differences between singleplex and multiplex recombineering and provide important clues for further improving multiplex recombination efficiency.
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Affiliation(s)
- Thimma R. Reddy
- Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, United Kingdom
| | - Emma J. Kelsall
- Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, United Kingdom
| | - Léna M. S. Fevat
- Center for Fisheries, Environment and Aquaculture Sciences, Lowestoft, NR33 0HT, United Kingdom
| | - Sarah E. Munson
- ES Cell Facility, Center for Core Biotechnology Services, Leicester, LE1 9HN, United Kingdom
| | - Shaun M. Cowley
- Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, United Kingdom
- * E-mail:
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28
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Reddy TR, Fevat LMS, Munson SE, Stewart AF, Cowley SM. Lambda red mediated gap repair utilizes a novel replicative intermediate in Escherichia coli. PLoS One 2015; 10:e0120681. [PMID: 25803509 PMCID: PMC4372340 DOI: 10.1371/journal.pone.0120681] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 02/05/2015] [Indexed: 11/19/2022] Open
Abstract
The lambda phage Red recombination system can mediate efficient homologous recombination in Escherichia coli, which is the basis of the DNA engineering technique termed recombineering. Red mediated insertion of DNA requires DNA replication, involves a single-stranded DNA intermediate and is more efficient on the lagging strand of the replication fork. Lagging strand recombination has also been postulated to explain the Red mediated repair of gapped plasmids by an Okazaki fragment gap filling model. Here, we demonstrate that gap repair involves a different strand independent mechanism. Gap repair assays examining the strand asymmetry of recombination did not show a lagging strand bias. Directly testing an ssDNA plasmid showed lagging strand recombination is possible but dsDNA plasmids did not employ this mechanism. Insertional recombination combined with gap repair also did not demonstrate preferential lagging strand bias, supporting a different gap repair mechanism. The predominant recombination route involved concerted insertion and subcloning though other routes also operated at lower frequencies. Simultaneous insertion of DNA resulted in modification of both strands and was unaffected by mutations to DNA polymerase I, responsible for Okazaki fragment maturation. The lower efficiency of an alternate Red mediated ends-in recombination pathway and the apparent lack of a Holliday junction intermediate suggested that gap repair does not involve a different Red recombination pathway. Our results may be explained by a novel replicative intermediate in gap repair that does not involve a replication fork. We exploited these observations by developing a new recombineering application based on concerted insertion and gap repair, termed SPI (subcloning plus insertion). SPI selected against empty vector background and selected for correct gap repair recombinants. We used SPI to simultaneously insert up to four different gene cassettes in a single recombineering reaction. Consequently, our findings have important implications for the understanding of E. coli replication and Red recombination.
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Affiliation(s)
- Thimma R. Reddy
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
| | - Léna M. S. Fevat
- Center for Fisheries, Environment and Aquaculture Sciences, Lowestoft, United Kingdom
| | - Sarah E. Munson
- ES Cell Facility, Centre for Core Biotechnology Services, University of Leicester, Leicester, United Kingdom
| | - A. Francis Stewart
- Genomics, BioInnovationsZentrum, Technische Universitaet Dresden, Dresden, Germany
| | - Shaun M. Cowley
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
- * E-mail:
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29
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Replicative DNA polymerase δ but not ε proofreads errors in Cis and in Trans. PLoS Genet 2015; 11:e1005049. [PMID: 25742645 PMCID: PMC4351087 DOI: 10.1371/journal.pgen.1005049] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 02/02/2015] [Indexed: 01/18/2023] Open
Abstract
It is now well established that in yeast, and likely most eukaryotic organisms, initial DNA replication of the leading strand is by DNA polymerase ε and of the lagging strand by DNA polymerase δ. However, the role of Pol δ in replication of the leading strand is uncertain. In this work, we use a reporter system in Saccharomyces cerevisiae to measure mutation rates at specific base pairs in order to determine the effect of heterozygous or homozygous proofreading-defective mutants of either Pol ε or Pol δ in diploid strains. We find that wild-type Pol ε molecules cannot proofread errors created by proofreading-defective Pol ε molecules, whereas Pol δ can not only proofread errors created by proofreading-defective Pol δ molecules, but can also proofread errors created by Pol ε-defective molecules. These results suggest that any interruption in DNA synthesis on the leading strand is likely to result in completion by Pol δ and also explain the higher mutation rates observed in Pol δ-proofreading mutants compared to Pol ε-proofreading defective mutants. For strains reverting via AT→GC, TA→GC, CG→AT, and GC→AT mutations, we find in addition a strong effect of gene orientation on mutation rate in proofreading-defective strains and demonstrate that much of this orientation dependence is due to differential efficiencies of mispair elongation. We also find that a 3′-terminal 8 oxoG, unlike a 3′-terminal G, is efficiently extended opposite an A and is not subject to proofreading. Proofreading mutations have been shown to result in tumor formation in both mice and humans; the results presented here can help explain the properties exhibited by those proofreading mutants. Many DNA polymerases are able to proofread their errors: after incorporation of a wrong base, the resulting mispair invokes an exonuclease activity of the polymerase that removes the mispaired base and allows replication to continue. Elimination of the proofreading activity thus results in much higher mutation rates. We demonstrate that the two major replicative DNA polymerases in yeast, Pol δ and Pol ε, have different proofreading abilities. In diploid cells, Pol ε is not able to proofread errors created by other Pol ε molecules, whereas Pol δ can proofread not only errors created by other Pol δ molecules but also errors created by Pol ε molecules. We also find that mispaired bases not corrected by proofreading have much different likelihoods of being extended, depending on the particular base-base mismatch. In humans, defects in Pol δ or Pol ε proofreading can lead to cancer, and these results help explain the formation of those tumors and the finding that Pol ε mutants seem to be found as frequently, or more so, in human tumors as Pol δ mutants.
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Abstract
Synthetic biology employs rational engineering principles to build biological systems from the libraries of standard, well characterized biological parts. Biological systems designed and built by synthetic biologists fulfill a plethora of useful purposes, ranging from better healthcare and energy production to biomanufacturing. Recent advancements in the synthesis, assembly and "booting-up" of synthetic genomes and in low and high-throughput genome engineering have paved the way for engineering on the genome-wide scale. One of the key goals of genome engineering is the construction of minimal genomes consisting solely of essential genes (genes indispensable for survival of living organisms). Besides serving as a toolbox to understand the universal principles of life, the cell encoded by minimal genome could be used to build a stringently controlled "cell factory" with a desired phenotype. This review provides an update on recent advances in the genome-scale engineering with particular emphasis on the engineering of minimal genomes. Furthermore, it presents an ongoing discussion to the scientific community for better suitability of minimal or robust cells for industrial applications.
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Affiliation(s)
- Mario Juhas
- a Department of Pathology , University of Cambridge , Cambridge , UK
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31
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Si T, Xiao H, Zhao H. Rapid prototyping of microbial cell factories via genome-scale engineering. Biotechnol Adv 2014; 33:1420-32. [PMID: 25450192 DOI: 10.1016/j.biotechadv.2014.11.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 11/13/2014] [Accepted: 11/13/2014] [Indexed: 10/24/2022]
Abstract
Advances in reading, writing and editing genetic materials have greatly expanded our ability to reprogram biological systems at the resolution of a single nucleotide and on the scale of a whole genome. Such capacity has greatly accelerated the cycles of design, build and test to engineer microbes for efficient synthesis of fuels, chemicals and drugs. In this review, we summarize the emerging technologies that have been applied, or are potentially useful for genome-scale engineering in microbial systems. We will focus on the development of high-throughput methodologies, which may accelerate the prototyping of microbial cell factories.
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Affiliation(s)
- Tong Si
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - Han Xiao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
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32
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Osahor AN, Tan CY, Sim EUH, Lee CW, Narayanan K. Short homologies efficiently generate detectable homologous recombination events. Anal Biochem 2014; 462:26-8. [PMID: 24929088 DOI: 10.1016/j.ab.2014.05.030] [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: 05/06/2014] [Revised: 05/29/2014] [Accepted: 05/30/2014] [Indexed: 10/25/2022]
Abstract
When recombineering bacterial artificial chromosomes (BACs), it is common practice to design the ends of the donor molecule with 50 bp of homology specifying its insertion site. We demonstrate that desired recombinants can be produced using intermolecular homologies as short as 15 bp. Although the use of shorter donor end regions decreases total recombinants by several fold, the frequency of recombinants with correctly inserted donor molecules was high enough for easy detection by simple polymerase chain reaction (PCR) screening. This observation may have important implications for the design of oligonucleotides for recombineering, including significant cost savings, especially for high-throughput projects that use large quantities of primers.
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Affiliation(s)
- Andrew N Osahor
- School of Science, Monash University Malaysia, 46150 Bandar Sunway, Selangor, Malaysia; Department of Biotechnology, Malaysia University of Science and Technology, 47301 Petaling Jaya, Selangor Darul Ehsan, Malaysia
| | - Chau-Yan Tan
- School of Science, Monash University Malaysia, 46150 Bandar Sunway, Selangor, Malaysia
| | - Edmund Ui-Hang Sim
- Department of Molecular Biology, Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia
| | - Choon-Weng Lee
- Laboratory of Microbial Ecology, Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Kumaran Narayanan
- School of Science, Monash University Malaysia, 46150 Bandar Sunway, Selangor, Malaysia; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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33
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Rapid editing and evolution of bacterial genomes using libraries of synthetic DNA. Nat Protoc 2014; 9:2301-16. [DOI: 10.1038/nprot.2014.082] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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34
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Fricker AD, Peters JE. Vulnerabilities on the lagging-strand template: opportunities for mobile elements. Annu Rev Genet 2014; 48:167-86. [PMID: 25195506 DOI: 10.1146/annurev-genet-120213-092046] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mobile genetic elements have the ability to move between positions in a genome. Some of these elements are capable of targeting one of the template strands during DNA replication. Examples found in bacteria include (a) Red recombination mediated by bacteriophage λ, (b) integration of group II mobile introns that reverse splice and reverse transcribe into DNA, (c) HUH endonuclease elements that move as single-stranded DNA, and (d) Tn7, a DNA cut-and-paste transposon that uses a target-site-selecting protein to target transposition into certain forms of DNA replication. In all of these examples, the lagging-strand template appears to be targeted using a variety of features specific to this strand. These features appear especially available in certain situations, such as when replication forks stall or collapse. In this review, we address the idea that features specific to the lagging-strand template represent vulnerabilities that are capitalized on by mobile genetic elements.
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Affiliation(s)
- Ashwana D Fricker
- Department of Microbiology, Cornell University, Ithaca, New York 14853;
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35
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Weller SK, Sawitzke JA. Recombination promoted by DNA viruses: phage λ to herpes simplex virus. Annu Rev Microbiol 2014; 68:237-58. [PMID: 25002096 DOI: 10.1146/annurev-micro-091313-103424] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The purpose of this review is to explore recombination strategies in DNA viruses. Homologous recombination is a universal genetic process that plays multiple roles in the biology of all organisms, including viruses. Recombination and DNA replication are interconnected, with recombination being essential for repairing DNA damage and supporting replication of the viral genome. Recombination also creates genetic diversity, and viral recombination mechanisms have important implications for understanding viral origins as well as the dynamic nature of viral-host interactions. Both bacteriophage λ and herpes simplex virus (HSV) display high rates of recombination, both utilizing their own proteins and commandeering cellular proteins to promote recombination reactions. We focus primarily on λ and HSV, as they have proven amenable to both genetic and biochemical analysis and have recently been shown to exhibit some surprising similarities that will guide future studies.
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Affiliation(s)
- Sandra K Weller
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, Connecticut 06030;
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36
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Gregg CJ, Lajoie MJ, Napolitano MG, Mosberg JA, Goodman DB, Aach J, Isaacs FJ, Church GM. Rational optimization of tolC as a powerful dual selectable marker for genome engineering. Nucleic Acids Res 2014; 42:4779-90. [PMID: 24452804 PMCID: PMC3985617 DOI: 10.1093/nar/gkt1374] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Selection has been invaluable for genetic manipulation, although counter-selection has historically exhibited limited robustness and convenience. TolC, an outer membrane pore involved in transmembrane transport in E. coli, has been implemented as a selectable/counter-selectable marker, but counter-selection escape frequency using colicin E1 precludes using tolC for inefficient genetic manipulations and/or with large libraries. Here, we leveraged unbiased deep sequencing of 96 independent lineages exhibiting counter-selection escape to identify loss-of-function mutations, which offered mechanistic insight and guided strain engineering to reduce counter-selection escape frequency by ∼40-fold. We fundamentally improved the tolC counter-selection by supplementing a second agent, vancomycin, which reduces counter-selection escape by 425-fold, compared colicin E1 alone. Combining these improvements in a mismatch repair proficient strain reduced counter-selection escape frequency by 1.3E6-fold in total, making tolC counter-selection as effective as most selectable markers, and adding a valuable tool to the genome editing toolbox. These improvements permitted us to perform stable and continuous rounds of selection/counter-selection using tolC, enabling replacement of 10 alleles without requiring genotypic screening for the first time. Finally, we combined these advances to create an optimized E. coli strain for genome engineering that is ∼10-fold more efficient at achieving allelic diversity than previous best practices.
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Affiliation(s)
- Christopher J Gregg
- Department of Genetics and Wyss Institute for Biologically Inspired Engineering, Harvard Medical School, Boston, MA 02115, USA, Program in Chemical Biology, Harvard University, Cambridge, MA 02138, USA, Biological and Biomedical Sciences, Harvard Medical School, Boston, MA 02115, USA and Molecular, Cellular, Developmental and Systems Biology Institute, Yale University, New Haven, CT 06516, USA
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37
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Accelerated protein engineering for chemical biotechnology via homologous recombination. Curr Opin Biotechnol 2013; 24:1017-22. [DOI: 10.1016/j.copbio.2013.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 02/28/2013] [Accepted: 03/05/2013] [Indexed: 12/22/2022]
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38
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Li Y, Gu Q, Lin Z, Wang Z, Chen T, Zhao X. Multiplex iterative plasmid engineering for combinatorial optimization of metabolic pathways and diversification of protein coding sequences. ACS Synth Biol 2013; 2:651-61. [PMID: 24041030 DOI: 10.1021/sb400051t] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Engineering complex biological systems typically requires combinatorial optimization to achieve the desired functionality. Here, we present Multiplex Iterative Plasmid Engineering (MIPE), which is a highly efficient and customized method for combinatorial diversification of plasmid sequences. MIPE exploits ssDNA mediated λ Red recombineering for the introduction of mutations, allowing it to target several sites simultaneously and generate libraries of up to 10(7) sequences in one reaction. We also describe "restriction digestion mediated co-selection (RD CoS)", which enables MIPE to produce enhanced recombineering efficiencies with greatly simplified coselection procedures. To demonstrate this approach, we applied MIPE to fine-tune gene expression level in the 5-gene riboflavin biosynthetic pathway and successfully isolated a clone with 2.67-fold improved production in less than a week. We further demonstrated the ability of MIPE for highly multiplexed diversification of protein coding sequence by simultaneously targeting 23 codons scattered along the 750 bp sequence. We anticipate this method to benefit the optimization of diverse biological systems in synthetic biology and metabolic engineering.
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Affiliation(s)
- Yifan Li
- Key Laboratory of Systems
Bioengineering,
Ministry of Education, and Department of Biochemical Engineering,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Qun Gu
- Key Laboratory of Systems
Bioengineering,
Ministry of Education, and Department of Biochemical Engineering,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Zhenquan Lin
- Key Laboratory of Systems
Bioengineering,
Ministry of Education, and Department of Biochemical Engineering,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Zhiwen Wang
- Key Laboratory of Systems
Bioengineering,
Ministry of Education, and Department of Biochemical Engineering,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Tao Chen
- Key Laboratory of Systems
Bioengineering,
Ministry of Education, and Department of Biochemical Engineering,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Xueming Zhao
- Key Laboratory of Systems
Bioengineering,
Ministry of Education, and Department of Biochemical Engineering,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People’s Republic of China
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39
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Lajoie MJ, Rovner AJ, Goodman DB, Aerni HR, Haimovich AD, Kuznetsov G, Mercer JA, Wang HH, Carr PA, Mosberg JA, Rohland N, Schultz PG, Jacobson JM, Rinehart J, Church GM, Isaacs FJ. Genomically recoded organisms expand biological functions. Science 2013; 342:357-60. [PMID: 24136966 PMCID: PMC4924538 DOI: 10.1126/science.1241459] [Citation(s) in RCA: 589] [Impact Index Per Article: 53.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We describe the construction and characterization of a genomically recoded organism (GRO). We replaced all known UAG stop codons in Escherichia coli MG1655 with synonymous UAA codons, which permitted the deletion of release factor 1 and reassignment of UAG translation function. This GRO exhibited improved properties for incorporation of nonstandard amino acids that expand the chemical diversity of proteins in vivo. The GRO also exhibited increased resistance to T7 bacteriophage, demonstrating that new genetic codes could enable increased viral resistance.
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Affiliation(s)
- Marc J. Lajoie
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Program in Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Alexis J. Rovner
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA
- Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Daniel B. Goodman
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Program in Medical Engineering and Medical Physics, Harvard–Massachusetts Institute of Technology (MIT) Division of Health Sciences and Technology, Cambridge, MA 02139, USA
| | - Hans-Rudolf Aerni
- Systems Biology Institute, Yale University, West Haven, CT 06516, USA
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT 06520, USA
| | - Adrian D. Haimovich
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA
- Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Gleb Kuznetsov
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | | | - Harris H. Wang
- Department of Systems Biology, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA
| | | | - Joshua A. Mosberg
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Program in Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Nadin Rohland
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Peter G. Schultz
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Joseph M. Jacobson
- Center for Bits and Atoms, MIT, Cambridge, MA 02139, USA
- MIT Media Lab, MIT, Cambridge, MA 02139, USA
| | - Jesse Rinehart
- Systems Biology Institute, Yale University, West Haven, CT 06516, USA
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT 06520, USA
| | - George M. Church
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, 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
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40
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Genome-scale engineering for systems and synthetic biology. Mol Syst Biol 2013; 9:641. [PMID: 23340847 PMCID: PMC3564264 DOI: 10.1038/msb.2012.66] [Citation(s) in RCA: 205] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 12/16/2012] [Indexed: 12/15/2022] Open
Abstract
This review provides an overview of methodologies and technologies enabling genome-scale engineering, focusing on the design, construction, and testing of modified genomes in a variety of organisms. Future applications for systems and synthetic biology are discussed. Genome-modification technologies enable the rational engineering and perturbation of biological systems. Historically, these methods have been limited to gene insertions or mutations at random or at a few pre-defined locations across the genome. The handful of methods capable of targetedgene editing suffered from low efficiencies, significant labor costs, or both. Recent advances have dramatically expanded our ability to engineer cells in a directed and combinatorial manner. Here, we review current technologies and methodologies for genome-scale engineering, discuss the prospects for extending efficient genome modification to new hosts, and explore the implications of continued advances toward the development of flexibly programmable chasses, novel biochemistries, and safer organismal and ecological engineering.
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41
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Poteete AR. Involvement of Escherichia coli DNA Replication Proteins in Phage Lambda Red-Mediated Homologous Recombination. PLoS One 2013; 8:e67440. [PMID: 23840702 PMCID: PMC3686724 DOI: 10.1371/journal.pone.0067440] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 05/20/2013] [Indexed: 11/19/2022] Open
Abstract
The Red recombination system of bacteriophage lambda is widely used for genetic engineering because of its ability to promote recombination between bacterial chromosomes or plasmids and linear DNA species introduced by electroporation. The process is known to be intimately tied to replication, but the cellular functions which participate with Red in this process are largely unknown. Here two such functions are identified: the GrpE-DnaK-DnaJ chaperone system, and DNA polymerase I. Mutations in either function are found to decrease the efficiency of Red recombination. grpE and dnaJ mutations which greatly decrease Red recombination with electroporated DNA species have only small effects on Red-mediated transduction. This recombination event specificity suggests that the involvement of GrpE-DnaJ-DnaK is not simply an effect on Red structure or stability.
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Affiliation(s)
- Anthony R. Poteete
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
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42
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Li XT, Thomason LC, Sawitzke JA, Costantino N, Court DL. Bacterial DNA polymerases participate in oligonucleotide recombination. Mol Microbiol 2013; 88:906-20. [PMID: 23634873 DOI: 10.1111/mmi.12231] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2013] [Indexed: 02/01/2023]
Abstract
Synthetic single-strand oligonucleotides (oligos) with homology to genomic DNA have proved to be highly effective for constructing designed mutations in targeted genomes, a process referred to as recombineering. The cellular functions important for this type of homologous recombination have yet to be determined. Towards this end, we have identified Escherichia coli functions that process the recombining oligo and affect bacteriophage λ Red-mediated oligo recombination. To determine the nature of oligo processing during recombination, each oligo contained multiple nucleotide changes: a single base change allowing recombinant selection, and silent changes serving as genetic markers to determine the extent of oligo processing during the recombination. Such oligos were often not incorporated into the host chromosome intact; many were partially degraded in the process of recombination. The position and number of these silent nucleotide changes within the oligo strongly affect both oligo processing and recombination frequency. Exonucleases, especially those associated with DNA Polymerases I and III, affect inheritance of the silent nucleotide changes in the oligos. We demonstrate for the first time that the major DNA polymerases (Pol I and Pol III) and DNA ligase are directly involved with oligo recombination.
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Affiliation(s)
- Xin-tian Li
- Molecular Control and Genetics Section, Gene Regulation and Chromosome Biology, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
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43
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Jeong J, Cho N, Jung D, Bang D. Genome-scale genetic engineering in Escherichia coli. Biotechnol Adv 2013; 31:804-10. [PMID: 23624241 DOI: 10.1016/j.biotechadv.2013.04.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 04/13/2013] [Accepted: 04/15/2013] [Indexed: 12/23/2022]
Abstract
Genome engineering has been developed to create useful strains for biological studies and industrial uses. However, a continuous challenge remained in the field: technical limitations in high-throughput screening and precise manipulation of strains. Today, technical improvements have made genome engineering more rapid and efficient. This review introduces recent advances in genome engineering technologies applied to Escherichia coli as well as multiplex automated genome engineering (MAGE), a recent technique proposed as a powerful toolkit due to its straightforward process, rapid experimental procedures, and highly efficient properties.
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Affiliation(s)
- Jaehwan Jeong
- Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea
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44
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Skretas G, Kolisis FN. Combinatorial approaches for inverse metabolic engineering applications. Comput Struct Biotechnol J 2013; 3:e201210021. [PMID: 24688681 PMCID: PMC3962077 DOI: 10.5936/csbj.201210021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 02/11/2013] [Accepted: 02/17/2013] [Indexed: 11/22/2022] Open
Abstract
Traditional metabolic engineering analyzes biosynthetic and physiological pathways, identifies bottlenecks, and makes targeted genetic modifications with the ultimate goal of increasing the production of high-value products in living cells. Such efforts have led to the development of a variety of organisms with industrially relevant properties. However, there are a number of cellular phenotypes important for research and the industry for which the rational selection of cellular targets for modification is not easy or possible. In these cases, strain engineering can be alternatively carried out using “inverse metabolic engineering”, an approach that first generates genetic diversity by subjecting a population of cells to a particular mutagenic process, and then utilizes genetic screens or selections to identify the clones exhibiting the desired phenotype. Given the availability of an appropriate screen for a particular property, the success of inverse metabolic engineering efforts usually depends on the level and quality of genetic diversity which can be generated. Here, we review classic and recently developed combinatorial approaches for creating such genetic diversity and discuss the use of these methodologies in inverse metabolic engineering applications.
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Affiliation(s)
- Georgios Skretas
- Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation, Athens, Greece
| | - Fragiskos N Kolisis
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens - Zografou Campus, Athens, Greece
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Boyle NR, Reynolds TS, Evans R, Lynch M, Gill RT. Recombineering to homogeneity: extension of multiplex recombineering to large-scale genome editing. Biotechnol J 2013; 8:515-22. [PMID: 23436787 DOI: 10.1002/biot.201200237] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 12/17/2012] [Accepted: 01/22/2013] [Indexed: 11/08/2022]
Abstract
Recombineering has been an essential tool for genetic engineering in microbes for many years and has enabled faster, more efficient engineering than previous techniques. There have been numerous studies that focus on improving recombineering efficiency, which can be divided into three main areas: (i) optimizing the oligo used for recombineering to enhance replication fork annealing and limit proofreading; (ii) mechanisms to modify the replisome itself, enabling an increased rate of annealing; and (iii) multiplexing recombineering targets and automation. These efforts have increased the efficiency of recombineering several hundred-fold. One area that has received far less attention is the problem of multiple chromosomes, which effectively decrease efficiency on a chromosomal basis, resulting in more sectored colonies, which require longer outgrowth to obtain clonal populations. Herein, we describe the problem of multiple chromosomes, discuss calculations predicting how many generations are needed to obtain a pure colony, and how changes in experimental procedure or genetic background can minimize the effect of multiple chromosomes.
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Affiliation(s)
- Nanette R Boyle
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO, USA
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