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Fujita H, Osaku A, Sakane Y, Yoshida K, Yamada K, Nara S, Mukai T, Su’etsugu M. Enzymatic Supercoiling of Bacterial Chromosomes Facilitates Genome Manipulation. ACS Synth Biol 2022; 11:3088-3099. [PMID: 35998348 PMCID: PMC9486964 DOI: 10.1021/acssynbio.2c00353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The physical stability of bacterial chromosomes is important for their in vitro manipulation, while genetic stability is important in vivo. However, extracted naked chromosomes in the open circular form are fragile due to nicks and gaps. Using a nick/gap repair and negative supercoiling reaction (named SCR), we first achieved the negative supercoiling of the whole genomes extracted from Escherichia coli and Vibrio natriegens cells. Supercoiled chromosomes of 0.2-4.6 megabase (Mb) were separated by size using a conventional agarose gel electrophoresis and served as DNA size markers. We also achieved the enzymatic replication of 1-2 Mb chromosomes using the reconstituted E. coli replication-cycle reaction (RCR). Electroporation-ready 1 Mb chromosomes were prepared by a modified SCR performed at a low salt concentration (L-SCR) and directly introduced into commercial electrocompetent E. coli cells. Since successful electroporation relies on the genetic stability of a chromosome in cells, genetically stable 1 Mb chromosomes were developed according to a portable chromosome format (PCF). Using physically and genetically stabilized chromosomes, the democratization of genome synthetic biology will be greatly accelerated.
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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: 5] [Impact Index Per Article: 2.5] [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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Mukai T, Yoneji T, Yamada K, Fujita H, Nara S, Su'etsugu M. Overcoming the Challenges of Megabase-Sized Plasmid Construction in Escherichia coli. ACS Synth Biol 2020; 9:1315-1327. [PMID: 32459960 DOI: 10.1021/acssynbio.0c00008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Although Escherichia coli has been a popular tool for plasmid construction, this bacterium was believed to be "unsuitable" for constructing a large plasmid whose size exceeds 500 kilobases. We assumed that traditional plasmid vectors may lack some regulatory DNA elements required for the stable replication and segregation of such a large plasmid. In addition, the use of a few site-specific recombination systems may facilitate cloning of large DNA segments. Here we show two strategies for constructing 1-megabase (1-Mb) secondary chromosomes by using new bacterial artificial chromosome (BAC) vectors. First, the 3-Mb genome of a genome-reduced E. coli strain was split into two chromosomes (2-Mb and 1-Mb), of which the smaller one has the origin of replication and the partitioning locus of the Vibrio tubiashii secondary chromosome. This chromosome fission method (Flp-POP cloning) works via flippase-mediated excision, which coincides with the reassembly of a split chloramphenicol resistance gene, allowing chloramphenicol selection. Next, we developed a new cloning method (oriT-POP cloning) and a fully equipped BAC vector (pMegaBAC1H) for developing a 1-Mb plasmid. Two 0.5-Mb genomic regions were sequentially transferred from two donor strains to a recipient strain via conjugation and captured by pMegaBAC1H in the recipient strain to produce a 1-Mb plasmid. This 1-Mb plasmid was transmissible to another E. coli strain via conjugation. Furthermore, these 1-Mb secondary chromosomes were amplifiable in vitro by using the reconstituted E. coli chromosome replication cycle reaction (RCR). These strategies and technologies would make popular E. coli cells a productive factory for designer chromosome engineering.
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Affiliation(s)
- Takahito Mukai
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
| | - Tatsuya Yoneji
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
| | - Kayoko Yamada
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
| | - Hironobu Fujita
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
| | - Seia Nara
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
| | - Masayuki Su'etsugu
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
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Klein CA, Emde L, Kuijpers A, Sobetzko P. MoCloFlex: A Modular Yet Flexible Cloning System. Front Bioeng Biotechnol 2019; 7:271. [PMID: 31750294 PMCID: PMC6843054 DOI: 10.3389/fbioe.2019.00271] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 09/30/2019] [Indexed: 02/04/2023] Open
Abstract
Modern cloning solutions are gradually replacing classical cloning methods. Current systems make use of libraries with predefined DNA parts that are joined by Golden-Gate reactions. However, these systems still suffer from specific inflexibilities and the lack of inter-compatibility. Here, we present Flexible Modular Cloning (MoCloFlex) which overcomes this inflexibility by introducing a set of linker- and position-vectors allowing free unit arrangement. Our system, therefore, provides a convenient way to design and build custom plasmids, and iterative assembly of large constructs. To support standardization in synthetic biology, MoCloFlex is compatible with the well-established Modular Cloning standard. Here, we present and characterize MoCloFlex for various applications with up to 12 fragments in a single restriction-ligation reaction.
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Affiliation(s)
- Carlo A. Klein
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps-Universität Marburg, Marburg, Germany
| | - Leonie Emde
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps-Universität Marburg, Marburg, Germany
| | - Aaron Kuijpers
- Department of Biology, University of Kassel, Kassel, Germany
| | - Patrick Sobetzko
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Philipps-Universität Marburg, Marburg, Germany
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Bruhn M, Schindler D, Kemter FS, Wiley MR, Chase K, Koroleva GI, Palacios G, Sozhamannan S, Waldminghaus T. Functionality of Two Origins of Replication in Vibrio cholerae Strains With a Single Chromosome. Front Microbiol 2018; 9:2932. [PMID: 30559732 PMCID: PMC6284228 DOI: 10.3389/fmicb.2018.02932] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/14/2018] [Indexed: 12/16/2022] Open
Abstract
Chromosomal inheritance in bacteria usually entails bidirectional replication of a single chromosome from a single origin into two copies and subsequent partitioning of one copy each into daughter cells upon cell division. However, the human pathogen Vibrio cholerae and other Vibrionaceae harbor two chromosomes, a large Chr1 and a small Chr2. Chr1 and Chr2 have different origins, an oriC-type origin and a P1 plasmid-type origin, respectively, driving the replication of respective chromosomes. Recently, we described naturally occurring exceptions to the two-chromosome rule of Vibrionaceae: i.e., Chr1 and Chr2 fused single chromosome V. cholerae strains, NSCV1 and NSCV2, in which both origins of replication are present. Using NSCV1 and NSCV2, here we tested whether two types of origins of replication can function simultaneously on the same chromosome or one or the other origin is silenced. We found that in NSCV1, both origins are active whereas in NSCV2 ori2 is silenced despite the fact that it is functional in an isolated context. The ori2 activity appears to be primarily determined by the copy number of the triggering site, crtS, which in turn is determined by its location with respect to ori1 and ori2 on the fused chromosome.
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Affiliation(s)
- Matthias Bruhn
- LOEWE Centre for Synthetic Microbiology-SYNMIKRO, Philipps-Universität Marburg, Marburg, Germany
| | - Daniel Schindler
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
| | - Franziska S Kemter
- LOEWE Centre for Synthetic Microbiology-SYNMIKRO, Philipps-Universität Marburg, Marburg, Germany
| | - Michael R Wiley
- United States Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States
| | - Kitty Chase
- United States Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States
| | - Galina I Koroleva
- United States Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States
| | - Gustavo Palacios
- United States Army Medical Research Institute of Infectious Diseases, Frederick, MD, United States
| | - Shanmuga Sozhamannan
- Defense Biological Product Assurance Office, Frederick, MD, United States.,The Tauri Group, LLC, Alexandria, VA, United States
| | - Torsten Waldminghaus
- LOEWE Centre for Synthetic Microbiology-SYNMIKRO, Philipps-Universität Marburg, Marburg, Germany
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Kemter FS, Messerschmidt SJ, Schallopp N, Sobetzko P, Lang E, Bunk B, Spröer C, Teschler JK, Yildiz FH, Overmann J, Waldminghaus T. Synchronous termination of replication of the two chromosomes is an evolutionary selected feature in Vibrionaceae. PLoS Genet 2018; 14:e1007251. [PMID: 29505558 PMCID: PMC5854411 DOI: 10.1371/journal.pgen.1007251] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 03/15/2018] [Accepted: 02/13/2018] [Indexed: 11/18/2022] Open
Abstract
Vibrio cholerae, the causative agent of the cholera disease, is commonly used as a model organism for the study of bacteria with multipartite genomes. Its two chromosomes of different sizes initiate their DNA replication at distinct time points in the cell cycle and terminate in synchrony. In this study, the time-delayed start of Chr2 was verified in a synchronized cell population. This replication pattern suggests two possible regulation mechanisms for other Vibrio species with different sized secondary chromosomes: Either all Chr2 start DNA replication with a fixed delay after Chr1 initiation, or the timepoint at which Chr2 initiates varies such that termination of chromosomal replication occurs in synchrony. We investigated these two models and revealed that the two chromosomes of various Vibrionaceae species terminate in synchrony while Chr2-initiation timing relative to Chr1 is variable. Moreover, the sequence and function of the Chr2-triggering crtS site recently discovered in V. cholerae were found to be conserved, explaining the observed timing mechanism. Our results suggest that it is beneficial for bacterial cells with multiple chromosomes to synchronize their replication termination, potentially to optimize chromosome related processes as dimer resolution or segregation.
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Affiliation(s)
- Franziska S. Kemter
- LOEWE Center for Synthetic Microbiology–SYNMIKRO, Philipps-Universität Marburg, Marburg, Germany
| | - Sonja J. Messerschmidt
- LOEWE Center for Synthetic Microbiology–SYNMIKRO, Philipps-Universität Marburg, Marburg, Germany
| | - Nadine Schallopp
- LOEWE Center for Synthetic Microbiology–SYNMIKRO, Philipps-Universität Marburg, Marburg, Germany
| | - Patrick Sobetzko
- LOEWE Center for Synthetic Microbiology–SYNMIKRO, Philipps-Universität Marburg, Marburg, Germany
| | - Elke Lang
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Boyke Bunk
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Cathrin Spröer
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Jennifer K. Teschler
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, United States of America
| | - Fitnat H. Yildiz
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, United States of America
| | - Jörg Overmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
- German Centre of Infection Research (DZIF), Partner Site Hannover–Braunschweig, Braunschweig, Germany
| | - Torsten Waldminghaus
- LOEWE Center for Synthetic Microbiology–SYNMIKRO, Philipps-Universität Marburg, Marburg, Germany
- * E-mail:
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Establishing a System for Testing Replication Inhibition of the Vibrio cholerae Secondary Chromosome in Escherichia coli. Antibiotics (Basel) 2017; 7:antibiotics7010003. [PMID: 29295515 PMCID: PMC5872114 DOI: 10.3390/antibiotics7010003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/05/2017] [Accepted: 12/20/2017] [Indexed: 12/29/2022] Open
Abstract
Regulators of DNA replication in bacteria are an attractive target for new antibiotics, as not only is replication essential for cell viability, but its underlying mechanisms also differ from those operating in eukaryotes. The genetic information of most bacteria is encoded on a single chromosome, but about 10% of species carry a split genome spanning multiple chromosomes. The best studied bacterium in this context is the human pathogen Vibrio cholerae, with a primary chromosome (Chr1) of 3 M bps, and a secondary one (Chr2) of about 1 M bps. Replication of Chr2 is under control of a unique mechanism, presenting a potential target in the development of V. cholerae-specific antibiotics. A common challenge in such endeavors is whether the effects of candidate chemicals can be focused on specific mechanisms, such as DNA replication. To test the specificity of antimicrobial substances independent of other features of the V. cholerae cell for the replication mechanism of the V. cholerae secondary chromosome, we establish the replication machinery in the heterologous E. coli system. We characterize an E. coli strain in which chromosomal replication is driven by the replication origin of V. cholerae Chr2. Surprisingly, the E. coli ori2 strain was not inhibited by vibrepin, previously found to inhibit ori2-based replication.
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BiFCROS: A Low-Background Fluorescence Repressor Operator System for Labeling of Genomic Loci. G3-GENES GENOMES GENETICS 2017; 7:1969-1977. [PMID: 28450375 PMCID: PMC5473772 DOI: 10.1534/g3.117.040782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Fluorescence-based methods are widely used to analyze elementary cell processes such as DNA replication or chromosomal folding and segregation. Labeling DNA with a fluorescent protein allows the visualization of its temporal and spatial organization. One popular approach is FROS (fluorescence repressor operator system). This method specifically labels DNA in vivo through binding of a fusion of a fluorescent protein and a repressor protein to an operator array, which contains numerous copies of the repressor binding site integrated into the genomic site of interest. Bound fluorescent proteins are then visible as foci in microscopic analyses and can be distinguished from the background fluorescence caused by unbound fusion proteins. Even though this method is widely used, no attempt has been made so far to decrease the background fluorescence to facilitate analysis of the actual signal of interest. Here, we present a new method that greatly reduces the background signal of FROS. BiFCROS (Bimolecular Fluorescence Complementation and Repressor Operator System) is based on fusions of repressor proteins to halves of a split fluorescent protein. Binding to a hybrid FROS array results in fluorescence signals due to bimolecular fluorescence complementation. Only proteins bound to the hybrid FROS array fluoresce, greatly improving the signal to noise ratio compared to conventional FROS. We present the development of BiFCROS and discuss its potential to be used as a fast and single-cell readout for copy numbers of genetic loci.
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