1
|
Guerrero-Bustamante CA, Hatfull GF. Bacteriophage tRNA-dependent lysogeny: requirement of phage-encoded tRNA genes for establishment of lysogeny. mBio 2024; 15:e0326023. [PMID: 38236026 PMCID: PMC10865867 DOI: 10.1128/mbio.03260-23] [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: 12/05/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024] Open
Abstract
Bacteriophages are large and diverse components of the biosphere, and many phages are temperate. Upon infection, temperate phages can establish lysogeny in which a prophage is typically integrated into the bacterial chromosome. Here, we describe the phenomenon of tRNA-dependent lysogeny, a previously unrecognized behavior of some temperate phages. tRNA-dependent lysogeny is characterized by two unusual features. First, a phage-encoded tyrosine family integrase mediates site-specific recombination between a phage attP site and a bacterial attB site overlapping a host tRNA gene. However, attP and attB share only a short (~10 bp) common core such that a functional tRNA is not reconstructed upon integration. Second, the phage encodes a tRNA of the same isotype as the disrupted but essential host tRNA, complementing its loss, and consequently is required for the survival of lysogenic progeny. As expected, an integrase-defective phage mutant forms turbid plaques, and bacterial progeny are immune to superinfection, but they lack stability, and the prophage is rapidly lost. In contrast, a tRNA-defective phage mutant forms clear plaques and more closely resembles a repressor mutant, and lysogens are recovered only at very low frequency through the use of secondary attachment sites elsewhere in the host genome. Integration-proficient plasmids derived from these phages must also carry a cognate phage tRNA gene for efficient integration, and these may be useful tools for mycobacterial genetics. We show that tRNA-dependent lysogeny is used by phages within multiple different groups of related viruses and may be prevalent elsewhere in the broader phage community.IMPORTANCEBacteriophages are the most numerous biological entities in the biosphere, and a substantial proportion of phages are temperate, forming stable lysogens in which a prophage copy of the genome integrates into the bacterial chromosome. Many phages encode a variety of tRNA genes whose roles are poorly understood, although it has been proposed that they enhance translational efficiencies in lytic growth or that they counteract host defenses that degrade host tRNAs. Here, we show that phage-encoded tRNAs play key roles in the establishment of lysogeny of some temperate phages. They do so by compensating for the loss of tRNA function when phages integrate at an attB site overlapping a tRNA gene but fail to reconstruct the tRNA at the attachment junction. In this system of tRNA-dependent lysogeny, the phage-encoded tRNA is required for lysogeny, and deletion of the phage tRNA gives rise to a clear plaque phenotype and obligate lytic growth.
Collapse
Affiliation(s)
| | - Graham F. Hatfull
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
2
|
Cerdán L, Álvarez B, Fernández LÁ. Massive integration of large gene libraries in the chromosome of Escherichia coli. Microb Biotechnol 2024; 17:e14367. [PMID: 37971317 PMCID: PMC10832519 DOI: 10.1111/1751-7915.14367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/21/2023] [Accepted: 10/22/2023] [Indexed: 11/19/2023] Open
Abstract
Large gene libraries are frequently created in Escherichia coli plasmids, which can induce cell toxicity and expression instability due to the high gene dosage. To address these limitations, gene libraries can be integrated in a single copy into the bacterial chromosome. Here, we describe an efficient system for the massive integration (MAIN) of large gene libraries in the E. coli chromosome that generates in-frame gene fusions that are expressed stably. MAIN uses a thermosensitive integrative plasmid that is linearized in vivo to promote extensive integration of the gene library via homologous recombination. Positive and negative selections efficiently remove bacteria lacking gene integration in the target site. We tested MAIN with a library of 107 VHH genes that encode nanobodies (Nbs). The integration of VHH genes into a custom target locus of the E. coli chromosome enabled stable expression and surface display of the Nbs. Next-generation DNA sequencing confirmed that MAIN preserved the diversity of the gene library after integration. Finally, we screened the integrated library to select Nbs that bind a specific antigen using magnetic and fluorescence-activated cell sorting. This allowed us to identify Nbs binding the epidermal growth factor receptor that were not previously isolated in a similar screening of a multicopy plasmid library. Our results demonstrate that MAIN enables large gene library integration into the E. coli chromosome, creating stably expressed in-frame fusions for functional screening.
Collapse
Affiliation(s)
- Lidia Cerdán
- Department of Microbial BiotechnologyCentro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC)MadridSpain
| | - Beatriz Álvarez
- Department of Microbial BiotechnologyCentro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC)MadridSpain
| | - Luis Ángel Fernández
- Department of Microbial BiotechnologyCentro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC)MadridSpain
| |
Collapse
|
3
|
Kohm K, Jalomo-Khayrova E, Krüger A, Basu S, Steinchen W, Bange G, Frunzke J, Hertel R, Commichau F, Czech L. Structural and functional characterization of MrpR, the master repressor of the Bacillus subtilis prophage SPβ. Nucleic Acids Res 2023; 51:9452-9474. [PMID: 37602373 PMCID: PMC10516654 DOI: 10.1093/nar/gkad675] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 07/11/2023] [Accepted: 08/09/2023] [Indexed: 08/22/2023] Open
Abstract
Prophages control their lifestyle to either be maintained within the host genome or enter the lytic cycle. Bacillus subtilis contains the SPβ prophage whose lysogenic state depends on the MrpR (YopR) protein, a key component of the lysis-lysogeny decision system. Using a historic B. subtilis strain harboring the heat-sensitive SPβ c2 mutant, we demonstrate that the lytic cycle of SPβ c2 can be induced by heat due to a single nucleotide exchange in the mrpR gene, rendering the encoded MrpRG136E protein temperature-sensitive. Structural characterization revealed that MrpR is a DNA-binding protein resembling the overall fold of tyrosine recombinases. MrpR has lost its recombinase function and the G136E exchange impairs its higher-order structure and DNA binding activity. Genome-wide profiling of MrpR binding revealed its association with the previously identified SPbeta repeated element (SPBRE) in the SPβ genome. MrpR functions as a master repressor of SPβ that binds to this conserved element to maintain lysogeny. The heat-inducible excision of the SPβ c2 mutant remains reliant on the serine recombinase SprA. A suppressor mutant analysis identified a previously unknown component of the lysis-lysogeny management system that is crucial for the induction of the lytic cycle of SPβ.
Collapse
Affiliation(s)
- Katharina Kohm
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Ekaterina Jalomo-Khayrova
- Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Phillips-University Marburg, Marburg, Germany
| | - Aileen Krüger
- Institute of Bio- and Geosciences, iBG-1: Biotechnology, FZ Jülich, Germany
| | - Syamantak Basu
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
| | - Wieland Steinchen
- Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Phillips-University Marburg, Marburg, Germany
| | - Gert Bange
- Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Phillips-University Marburg, Marburg, Germany
- Max-Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Julia Frunzke
- Institute of Bio- and Geosciences, iBG-1: Biotechnology, FZ Jülich, Germany
| | - Robert Hertel
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
- Department of Genomic and Applied Microbiology, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Göttingen, Germany
| | - Fabian M Commichau
- FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, Germany
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Laura Czech
- Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Phillips-University Marburg, Marburg, Germany
| |
Collapse
|
4
|
Singh C, Kumar R, Sehgal H, Bhati S, Singhal T, Gayacharan, Nimmy MS, Yadav R, Gupta SK, Abdallah NA, Hamwieh A, Kumar R. Unclasping potentials of genomics and gene editing in chickpea to fight climate change and global hunger threat. Front Genet 2023; 14:1085024. [PMID: 37144131 PMCID: PMC10153629 DOI: 10.3389/fgene.2023.1085024] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 03/24/2023] [Indexed: 09/09/2023] Open
Abstract
Genomics and genome editing promise enormous opportunities for crop improvement and elementary research. Precise modification in the specific targeted location of a genome has profited over the unplanned insertional events which are generally accomplished employing unadventurous means of genetic modifications. The advent of new genome editing procedures viz; zinc finger nucleases (ZFNs), homing endonucleases, transcription activator like effector nucleases (TALENs), Base Editors (BEs), and Primer Editors (PEs) enable molecular scientists to modulate gene expressions or create novel genes with high precision and efficiency. However, all these techniques are exorbitant and tedious since their prerequisites are difficult processes that necessitate protein engineering. Contrary to first generation genome modifying methods, CRISPR/Cas9 is simple to construct, and clones can hypothetically target several locations in the genome with different guide RNAs. Following the model of the application in crop with the help of the CRISPR/Cas9 module, various customized Cas9 cassettes have been cast off to advance mark discrimination and diminish random cuts. The present study discusses the progression in genome editing apparatuses, and their applications in chickpea crop development, scientific limitations, and future perspectives for biofortifying cytokinin dehydrogenase, nitrate reductase, superoxide dismutase to induce drought resistance, heat tolerance and higher yield in chickpea to encounter global climate change, hunger and nutritional threats.
Collapse
Affiliation(s)
- Charul Singh
- USBT, Guru Govind Singh Indraprastha University, Delhi, India
| | - Ramesh Kumar
- Department of Biochemistry, University of Allahabad Prayagraj, Prayagraj, India
| | - Hansa Sehgal
- Department of Biological Sciences, Birla Institute of Technology and Sciences, Pilani, India
| | - Sharmista Bhati
- School of Biotechnology, Gautam Buddha University, Greater Noida, India
| | - Tripti Singhal
- Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Gayacharan
- Division of Germplasm Evaluation, ICAR- National Bureau of Plant Genetic Resources, New Delhi, India
| | - M. S. Nimmy
- ICAR-National Institute for Plant Biotechnology, New Delhi, India
| | | | | | | | - Aladdin Hamwieh
- The International Center for Agricultural Research in the Dry Areas (ICARDA), Cairo, Egypt
| | - Rajendra Kumar
- Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India
| |
Collapse
|
5
|
Systematic Discovery of a New Catalogue of Tyrosine-Type Integrases in Bacterial Genomic Islands. Appl Environ Microbiol 2023; 89:e0173822. [PMID: 36719242 PMCID: PMC9972944 DOI: 10.1128/aem.01738-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Site-specific recombinases (integrases) can mediate the horizontal transfer of genomic islands. The ability to integrate large DNA sequences into target sites is very important for genetic engineering in prokaryotic and eukaryotic cells. Here, we characterized an unprecedented catalogue of 530 tyrosine-type integrases by examining genes potentially encoding tyrosine integrases in bacterial genomic islands. The phylogeny of putative tyrosine integrases revealed that these integrases form an evolutionary clade that is distinct from those already known and are affiliated with novel integrase groups. We systematically searched for candidate integrase genes, and their integration activities were validated in a bacterial model. We verified the integration functions of six representative novel integrases by using a two-plasmid integration system consisting of a donor plasmid carrying the integrase gene and attP site and a recipient plasmid harboring an attB site in recA-deficient Escherichia coli. Further quantitative reverse transcription-PCR (qRT-PCR) assays validated that the six selected integrases can be expressed with their native promoters in E. coli. The attP region reductions showed that the extent of attP sites of integrases is approximately 200 bp for integration capacity. In addition, mutational analysis showed that the conserved tyrosine at the C terminus is essential for catalysis, confirming that these candidate proteins belong to the tyrosine-type recombinase superfamily, i.e., tyrosine integrases. This study revealed that the novel integrases from bacterial genomic islands have site-specific recombination functions, which is of physiological significance for their genomic islands in bacterial chromosomes. More importantly, our discovery expands the toolbox for genetic engineering, especially for efficient integration activity. IMPORTANCE Site-specific recombinases or integrases have high specificity for DNA large fragment integration, which is urgently needed for gene editing. However, known integrases are not sufficient for meeting multiple integrations. In this work, we discovered an array of integrases through bioinformatics analysis in bacterial genomes. Phylogeny and functional assays revealed that these new integrases belong to tyrosine-type integrases and have the ability to conduct site-specific recombination. Moreover, attP region extent and catalysis site analysis were characterized. Our study provides the methodology for discovery of novel integrases and increases the capacity of weapon pool for genetic engineering in bacteria.
Collapse
|
6
|
Simple and Rapid Site-Specific Integration of Multiple Heterologous DNAs into the Escherichia coli Chromosome. J Bacteriol 2023; 205:e0033822. [PMID: 36655997 PMCID: PMC9945576 DOI: 10.1128/jb.00338-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Escherichia coli is the most studied and well understood microorganism, but research in this system can still be limited by available genetic tools, including the ability to rapidly integrate multiple DNA constructs efficiently into the chromosome. Site-specific, large serine-recombinases can be useful tools, catalyzing a single, unidirectional recombination event between 2 specific DNA sequences, attB and attP, without requiring host proteins for functionality. Using these recombinases, we have developed a system to integrate up to 12 genetic constructs sequentially and stably into in the E. coli chromosome. A cassette of attB sites was inserted into the chromosome and the corresponding recombinases were cloned onto temperature sensitive plasmids to mediate recombination between a non-replicating, attP-containing "cargo" plasmid and the corresponding attB site on the chromosome. The efficiency of DNA insertion into the E. coli chromosome was approximately 107 CFU/μg DNA for six of the recombinases when the competent cells already contained the recombinase-expressing plasmid and approximately 105 CFU/μg DNA or higher when the recombinase-expressing plasmid and "cargo" plasmid were co-transformed. The "cargo" plasmid contains ΦC31 recombination sites flanking the antibiotic gene, allowing for resistance markers to be removed and reused following transient expression of the ΦC31 recombinase. As an example of the utility of this system, eight DNA methyltransferases from Clostridium clariflavum 4-2a were inserted into the E. coli chromosome to methylate plasmid DNA for evasion of the C. clariflavum restriction systems, enabling the first demonstration of transformation of this cellulose-degrading species. IMPORTANCE More rapid genetic tools can help accelerate strain engineering, even in advanced hosts like Escherichia coli. Here, we adapt a suite of site-specific recombinases to enable simple, rapid, and highly efficient site-specific integration of heterologous DNA into the chromosome. This utility of this system was demonstrated by sequential insertion of eight DNA methyltransferases into the E. coli chromosome, allowing plasmid DNA to be protected from restriction in Clostridium clariflavum and enabling genetic transformation of this organism. This integration system should also be highly portable into non-model organisms.
Collapse
|
7
|
Conway C, Beckett MC, Dorman CJ. The DNA relaxation-dependent OFF-to-ON biasing of the type 1 fimbrial genetic switch requires the Fis nucleoid-associated protein. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001283. [PMID: 36748578 PMCID: PMC9993118 DOI: 10.1099/mic.0.001283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The structural genes expressing type 1 fimbriae in Escherichia coli alternate between expressed (phase ON) and non-expressed (phase OFF) states due to inversion of the 314 bp fimS genetic switch. The FimB tyrosine integrase inverts fimS by site-specific recombination, alternately connecting and disconnecting the fim operon, encoding the fimbrial subunit protein and its associated secretion and adhesin factors, to and from its transcriptional promoter within fimS. Site-specific recombination by the FimB recombinase becomes biased towards phase ON as DNA supercoiling is relaxed, a condition that occurs when bacteria approach the stationary phase of the growth cycle. This effect can be mimicked in exponential phase cultures by inhibiting the negative DNA supercoiling activity of DNA gyrase. We report that this bias towards phase ON depends on the presence of the Fis nucleoid-associated protein. We mapped the Fis binding to a site within the invertible fimS switch by DNase I footprinting. Disruption of this binding site by base substitution mutagenesis abolishes both Fis binding and the ability of the mutated switch to sustain its phase ON bias when DNA is relaxed, even in bacteria that produce the Fis protein. In addition, the Fis binding site overlaps one of the sites used by the Lrp protein, a known directionality determinant of fimS inversion that also contributes to phase ON bias. The Fis–Lrp relationship at fimS is reminiscent of that between Fis and Xis when promoting DNA relaxation-dependent excision of bacteriophage λ from the E. coli chromosome. However, unlike the co-binding mechanism used by Fis and Xis at λ attR, the Fis–Lrp relationship at fimS involves competitive binding. We discuss these findings in the context of the link between fimS inversion biasing and the physiological state of the bacterium.
Collapse
Affiliation(s)
- Colin Conway
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland.,Present address: Technical University of the Atlantic, Galway, Ireland
| | - Michael C Beckett
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
| | - Charles J Dorman
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
| |
Collapse
|
8
|
Armianinova DK, Karpov DS, Kotliarova MS, Goncharenko AV. Genetic Engineering in Mycobacteria. Mol Biol 2022. [DOI: 10.1134/s0026893322060036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Abstract
Genetic tools for targeted modification of the mycobacterial genome contribute to the understanding of the physiology and virulence mechanisms of mycobacteria. Human and animal pathogens, such as the Mycobacterium tuberculosis complex, which causes tuberculosis, and M. leprae, which causes leprosy, are of particular importance. Genetic research opens up novel opportunities to identify and validate new targets for antibacterial drugs and to develop improved vaccines. Although mycobacteria are difficult to work with due to their slow growth rate and a limited possibility to transfer genetic information, significant progress has been made in developing genetic engineering methods for mycobacteria. The review considers the main approaches to changing the mycobacterial genome in a targeted manner, including homologous and site-specific recombination and use of the CRISPR/Cas system.
Collapse
|
9
|
Characterization of a New Temperate Escherichia coli Phage vB_EcoP_ZX5 and Its Regulatory Protein. Pathogens 2022; 11:pathogens11121445. [PMID: 36558779 PMCID: PMC9782041 DOI: 10.3390/pathogens11121445] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/23/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022] Open
Abstract
The study of the interaction between temperate phages and bacteria is vital to understand their role in the development of human diseases. In this study, a novel temperate Escherichia coli phage, vB_EcoP_ZX5, with a genome size of 39,565 bp, was isolated from human fecal samples. It has a short tail and belongs to the genus Uetakevirus and the family Podoviridae. Phage vB_EcoP_ZX5 encodes three lysogeny-related proteins (ORF12, ORF21, and ORF4) and can be integrated into the 3'-end of guaA of its host E. coli YO1 for stable transmission to offspring bacteria. Phage vB_EcoP_ZX5 in lysogenized E. coli YO1+ was induced spontaneously, with a free phage titer of 107 PFU/mL. The integration of vB_EcoP_ZX5 had no significant effect on growth, biofilm, environmental stress response, antibiotic sensitivity, adherence to HeLa cells, and virulence of E. coli YO1. The ORF4 anti-repressor, ORF12 integrase, and ORF21 repressors that affect the lytic-lysogenic cycle of vB_EcoP_ZX5 were verified by protein overexpression. We could tell from changes of the number of total phages and the transcription level of phage genes that repressor protein is the key determinant of lytic-to-lysogenic conversion, and anti-repressor protein promotes the conversion from lysogenic cycle to lytic cycle.
Collapse
|
10
|
Williams JD, Voziyanova E, Voziyanov Y. The bacteriophage lambda integrase catalytic domain can be modified to act with the regulatory domain as a recombination-competent binary recombinase. J Biol Chem 2022; 299:102721. [PMID: 36410432 PMCID: PMC9791396 DOI: 10.1016/j.jbc.2022.102721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 11/08/2022] [Accepted: 11/10/2022] [Indexed: 11/21/2022] Open
Abstract
Site-specific recombinase Int mediates integration of the bacteriophage λ genome into the Escherichia coli chromosome. Integration occurs once the Int tetramer, assisted by the integration host factor IHF, forms the intasome, a higher order structure, within which Int, a heterobivalent protein, interacts with two nonhomologous DNA sequences: the core recombination sites and the accessory arm sites. The binding to these sites is mediated by the catalytic C-terminal domain (CTD) and the regulatory N-terminal domain (NTD) of Int, respectively. Within Int, the NTD can activate or inhibit the recombination activity of the CTD depending on whether the NTD is bound to the arm sites. The CTD alone cannot mediate recombination, and even when the NTD and the CTD are mixed together as individual polypeptides, the NTD cannot trigger recombination in the CTD. In this work, we set to determine what modifications can unlock the recombination activity in the CTD alone and how the CTD can be modified to respond to recombination-triggering signals from the NTD. For this, we performed a series of genetic analyses, which showed that a single mutation that stabilizes the CTD on DNA, E174K, allows the CTD to recombine the core DNA sequences. When the NTD is paired with the CTD (E174K) that also bears a short polypeptide from the C terminus of the NTD, the resulting binary Int can recombine arm-bearing substrates. Our results provide insights into the molecular basis of the regulation of the Int activity and suggest how binary recombinases of the integrase type can be engineered.
Collapse
Affiliation(s)
- Joe D Williams
- School of Biosciences, Louisiana Tech University, Ruston, Louisiana, USA
| | - Eugenia Voziyanova
- School of Biosciences, Louisiana Tech University, Ruston, Louisiana, USA
| | - Yuri Voziyanov
- School of Biosciences, Louisiana Tech University, Ruston, Louisiana, USA.
| |
Collapse
|
11
|
Zhang G, Cui Q, Li J, Guo R, Leclercq SO, Du L, Tang N, Song Y, Wang C, Zhao F, Feng J. The integrase of genomic island GIsul2 mediates the mobilization of GIsul2 and ISCR-related element CR2-sul2 unit through site-specific recombination. Front Microbiol 2022; 13:905865. [PMID: 35979485 PMCID: PMC9376610 DOI: 10.3389/fmicb.2022.905865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
In the worldwide health threat posed by antibiotic-resistant bacterial pathogens, mobile genetic elements (MGEs) play a critical role in favoring the dissemination of resistance genes. Among them, the genomic island GIsul2 and the ISCR-related element CR2-sul2 unit are believed to participate in this dissemination. However, the mobility of the two elements has not yet been demonstrated. Here, we found that the GIsul2 and CR2-sul2 units can excise from the host chromosomal attachment site (attB) in Shigella flexneri. Through establishing a two-plasmid mobilization system composed of a donor plasmid bearing the GIsul2 and a trap plasmid harboring the attB in recA-deficient Escherichia coli, we reveal that the integrase of GIsul2 can perform the excision and integration of GIsul2 and CR2-sul2 unit by site-specific recombination between att core sites. Furthermore, we demonstrate that the integrase and the att sites are required for mobility through knockout experiments. Our findings provide the first experimental characterization of the mobility of GIsul2 and CR2-sul2 units mediated by integrase. They also suggest a potential and unappreciated role of the GIsul2 integrase family in the dissemination of CR2-sul2 units carrying various resistance determinants in between.
Collapse
Affiliation(s)
- Gang Zhang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Qinna Cui
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Jianjuan Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Ruiliang Guo
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | | | - Lifeng Du
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
| | - Na Tang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Yuqin Song
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Chao Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Fangqing Zhao
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
| | - Jie Feng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- *Correspondence: Jie Feng
| |
Collapse
|
12
|
Bioinformatic and experimental characterization of SEN1998: a conserved gene carried by the Enterobacteriaceae-associated ROD21-like family of genomic islands. Sci Rep 2022; 12:2435. [PMID: 35165310 PMCID: PMC8844411 DOI: 10.1038/s41598-022-06183-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 01/12/2022] [Indexed: 12/20/2022] Open
Abstract
Genomic islands (GIs) are horizontally transferred elements that shape bacterial genomes and contributes to the adaptation to different environments. Some GIs encode an integrase and a recombination directionality factor (RDF), which are the molecular GI-encoded machinery that promotes the island excision from the chromosome, the first step for the spread of GIs by horizontal transfer. Although less studied, this process can also play a role in the virulence of bacterial pathogens. While the excision of GIs is thought to be similar to that observed in bacteriophages, this mechanism has been only studied in a few families of islands. Here, we aimed to gain a better understanding of the factors involved in the excision of ROD21 a pathogenicity island of the food-borne pathogen Salmonella enterica serovar Enteritidis and the most studied member of the recently described Enterobacteriaceae-associated ROD21-like family of GIs. Using bioinformatic and experimental approaches, we characterized the conserved gene SEN1998, showing that it encodes a protein with the features of an RDF that binds to the regulatory regions involved in the excision of ROD21. While deletion or overexpression of SEN1998 did not alter the expression of the integrase-encoding gene SEN1970, a slight but significant trend was observed in the excision of the island. Surprisingly, we found that the expression of both genes, SEN1998 and SEN1970, were negatively correlated to the excision of ROD21 which showed a growth phase-dependent pattern. Our findings contribute to the growing body of knowledge regarding the excision of GIs, providing insights about ROD21 and the recently described EARL family of genomic islands.
Collapse
|
13
|
Gauthier CH, Abad L, Venbakkam AK, Malnak J, Russell D, Hatfull G. OUP accepted manuscript. Nucleic Acids Res 2022; 50:e75. [PMID: 35451479 PMCID: PMC9303363 DOI: 10.1093/nar/gkac273] [Citation(s) in RCA: 10] [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: 12/20/2021] [Revised: 03/11/2022] [Accepted: 04/06/2022] [Indexed: 11/26/2022] Open
Abstract
Advances in genome sequencing have produced hundreds of thousands of bacterial genome sequences, many of which have integrated prophages derived from temperate bacteriophages. These prophages play key roles by influencing bacterial metabolism, pathogenicity, antibiotic resistance, and defense against viral attack. However, they vary considerably even among related bacterial strains, and they are challenging to identify computationally and to extract precisely for comparative genomic analyses. Here, we describe DEPhT, a multimodal tool for prophage discovery and extraction. It has three run modes that facilitate rapid screening of large numbers of bacterial genomes, precise extraction of prophage sequences, and prophage annotation. DEPhT uses genomic architectural features that discriminate between phage and bacterial sequences for efficient prophage discovery, and targeted homology searches for precise prophage extraction. DEPhT is designed for prophage discovery in Mycobacterium genomes but can be adapted broadly to other bacteria. We deploy DEPhT to demonstrate that prophages are prevalent in Mycobacterium strains but are absent not only from the few well-characterized Mycobacterium tuberculosis strains, but also are absent from all ∼30 000 sequenced M. tuberculosis strains.
Collapse
Affiliation(s)
| | | | - Ananya K Venbakkam
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Julia Malnak
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Daniel A Russell
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Graham F Hatfull
- To whom correspondence should be addressed. Tel: +1 412 624 6975;
| |
Collapse
|
14
|
Badel C, Da Cunha V, Oberto J. Archaeal tyrosine recombinases. FEMS Microbiol Rev 2021; 45:fuab004. [PMID: 33524101 PMCID: PMC8371274 DOI: 10.1093/femsre/fuab004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 01/13/2021] [Indexed: 12/16/2022] Open
Abstract
The integration of mobile genetic elements into their host chromosome influences the immediate fate of cellular organisms and gradually shapes their evolution. Site-specific recombinases catalyzing this integration have been extensively characterized both in bacteria and eukarya. More recently, a number of reports provided the in-depth characterization of archaeal tyrosine recombinases and highlighted new particular features not observed in the other two domains. In addition to being active in extreme environments, archaeal integrases catalyze reactions beyond site-specific recombination. Some of these integrases can catalyze low-sequence specificity recombination reactions with the same outcome as homologous recombination events generating deep rearrangements of their host genome. A large proportion of archaeal integrases are termed suicidal due to the presence of a specific recombination target within their own gene. The paradoxical maintenance of integrases that disrupt their gene upon integration implies novel mechanisms for their evolution. In this review, we assess the diversity of the archaeal tyrosine recombinases using a phylogenomic analysis based on an exhaustive similarity network. We outline the biochemical, ecological and evolutionary properties of these enzymes in the context of the families we identified and emphasize similarities and differences between archaeal recombinases and their bacterial and eukaryal counterparts.
Collapse
Affiliation(s)
- Catherine Badel
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Violette Da Cunha
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Jacques Oberto
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| |
Collapse
|
15
|
Kamagata K, Itoh Y, Tan C, Mano E, Wu Y, Mandali S, Takada S, Johnson RC. Testing mechanisms of DNA sliding by architectural DNA-binding proteins: dynamics of single wild-type and mutant protein molecules in vitro and in vivo. Nucleic Acids Res 2021; 49:8642-8664. [PMID: 34352099 PMCID: PMC8421229 DOI: 10.1093/nar/gkab658] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 07/10/2021] [Accepted: 07/22/2021] [Indexed: 01/06/2023] Open
Abstract
Architectural DNA-binding proteins (ADBPs) are abundant constituents of eukaryotic or bacterial chromosomes that bind DNA promiscuously and function in diverse DNA reactions. They generate large conformational changes in DNA upon binding yet can slide along DNA when searching for functional binding sites. Here we investigate the mechanism by which ADBPs diffuse on DNA by single-molecule analyses of mutant proteins rationally chosen to distinguish between rotation-coupled diffusion and DNA surface sliding after transient unbinding from the groove(s). The properties of yeast Nhp6A mutant proteins, combined with molecular dynamics simulations, suggest Nhp6A switches between two binding modes: a static state, in which the HMGB domain is bound within the minor groove with the DNA highly bent, and a mobile state, where the protein is traveling along the DNA surface by means of its flexible N-terminal basic arm. The behaviors of Fis mutants, a bacterial nucleoid-associated helix-turn-helix dimer, are best explained by mobile proteins unbinding from the major groove and diffusing along the DNA surface. Nhp6A, Fis, and bacterial HU are all near exclusively associated with the chromosome, as packaged within the bacterial nucleoid, and can be modeled by three diffusion modes where HU exhibits the fastest and Fis the slowest diffusion.
Collapse
Affiliation(s)
- Kiyoto Kamagata
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Yuji Itoh
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Cheng Tan
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Eriko Mano
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Yining Wu
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Sridhar Mandali
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1737, USA
| | - Shoji Takada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Reid C Johnson
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1737, USA.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| |
Collapse
|
16
|
Smyshlyaev G, Bateman A, Barabas O. Sequence analysis of tyrosine recombinases allows annotation of mobile genetic elements in prokaryotic genomes. Mol Syst Biol 2021; 17:e9880. [PMID: 34018328 PMCID: PMC8138268 DOI: 10.15252/msb.20209880] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 04/18/2021] [Accepted: 04/20/2021] [Indexed: 11/16/2022] Open
Abstract
Mobile genetic elements (MGEs) sequester and mobilize antibiotic resistance genes across bacterial genomes. Efficient and reliable identification of such elements is necessary to follow resistance spreading. However, automated tools for MGE identification are missing. Tyrosine recombinase (YR) proteins drive MGE mobilization and could provide markers for MGE detection, but they constitute a diverse family also involved in housekeeping functions. Here, we conducted a comprehensive survey of YRs from bacterial, archaeal, and phage genomes and developed a sequence-based classification system that dissects the characteristics of MGE-borne YRs. We revealed that MGE-related YRs evolved from non-mobile YRs by acquisition of a regulatory arm-binding domain that is essential for their mobility function. Based on these results, we further identified numerous unknown MGEs. This work provides a resource for comparative analysis and functional annotation of YRs and aids the development of computational tools for MGE annotation. Additionally, we reveal how YRs adapted to drive gene transfer across species and provide a tool to better characterize antibiotic resistance dissemination.
Collapse
Affiliation(s)
- Georgy Smyshlyaev
- European Molecular Biology LaboratoryEuropean Bioinformatics Institute (EMBL‐EBI)HinxtonUK
- European Molecular Biology Laboratory (EMBL)Structural and Computational Biology UnitHeidelbergGermany
- Department of Molecular BiologyUniversity of GenevaGenevaSwitzerland
| | - Alex Bateman
- European Molecular Biology LaboratoryEuropean Bioinformatics Institute (EMBL‐EBI)HinxtonUK
| | - Orsolya Barabas
- European Molecular Biology Laboratory (EMBL)Structural and Computational Biology UnitHeidelbergGermany
- Department of Molecular BiologyUniversity of GenevaGenevaSwitzerland
| |
Collapse
|
17
|
Abstract
Mobile genetic elements (MGEs) often encode integrases which catalyze the site-specific insertion of their genetic information into the host genome and the reverse reaction of excision. Hyperthermophilic archaea harbor integrases belonging to the SSV-family which carry the MGE recombination site within their open reading frame. Upon integration into the host genome, SSV integrases disrupt their own gene into two inactive pseudogenes and are termed suicidal for this reason. The evolutionary maintenance of suicidal integrases, concurring with the high prevalence and multiples recruitments of these recombinases by archaeal MGEs, is highly paradoxical. To elucidate this phenomenon, we analyzed the wide phylogenomic distribution of a prominent class of suicidal integrases which revealed a highly variable integration site specificity. Our results highlighted the remarkable hybrid nature of these enzymes encoded from the assembly of inactive pseudogenes of different origins. The characterization of the biological properties of one of these integrases, IntpT26-2 showed that this enzyme was active over a wide range of temperatures up to 99 °C and displayed a less-stringent site specificity requirement than comparable integrases. These observations concurred in explaining the pervasiveness of these suicidal integrases in the most hyperthermophilic organisms. The biochemical and phylogenomic data presented here revealed a target site switching system operating on highly thermostable integrases and suggested a new model for split gene reconstitution. By generating fast-evolving pseudogenes at high frequency, suicidal integrases constitute a powerful model to approach the molecular mechanisms involved in the generation of active genes variants by the recombination of proto-genes.
Collapse
Affiliation(s)
- Catherine Badel
- Microbiology Department, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University of Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette cedex, France
| | - Violette Da Cunha
- Microbiology Department, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University of Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette cedex, France
| | - Patrick Forterre
- Microbiology Department, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University of Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette cedex, France.,Unité de Biologie Moléculaire du Gène chez les Extrêmophiles, Département de Microbiologie, Institut Pasteur, Paris, France
| | - Jacques Oberto
- Microbiology Department, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, University of Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette cedex, France
| |
Collapse
|
18
|
Kamagata K, Ouchi K, Tan C, Mano E, Mandali S, Wu Y, Takada S, Takahashi S, Johnson RC. The HMGB chromatin protein Nhp6A can bypass obstacles when traveling on DNA. Nucleic Acids Res 2020; 48:10820-10831. [PMID: 32997109 PMCID: PMC7641734 DOI: 10.1093/nar/gkaa799] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 08/13/2020] [Accepted: 09/15/2020] [Indexed: 12/16/2022] Open
Abstract
DNA binding proteins rapidly locate their specific DNA targets through a combination of 3D and 1D diffusion mechanisms, with the 1D search involving bidirectional sliding along DNA. However, even in nucleosome-free regions, chromosomes are highly decorated with associated proteins that may block sliding. Here we investigate the ability of the abundant chromatin-associated HMGB protein Nhp6A from Saccharomyces cerevisiae to travel along DNA in the presence of other architectural DNA binding proteins using single-molecule fluorescence microscopy. We observed that 1D diffusion by Nhp6A molecules is retarded by increasing densities of the bacterial proteins Fis and HU and by Nhp6A, indicating these structurally diverse proteins impede Nhp6A mobility on DNA. However, the average travel distances were larger than the average distances between neighboring proteins, implying Nhp6A is able to bypass each of these obstacles. Together with molecular dynamics simulations, our analyses suggest two binding modes: mobile molecules that can bypass barriers as they seek out DNA targets, and near stationary molecules that are associated with neighboring proteins or preferred DNA structures. The ability of mobile Nhp6A molecules to bypass different obstacles on DNA suggests they do not block 1D searches by other DNA binding proteins.
Collapse
Affiliation(s)
- Kiyoto Kamagata
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.,Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.,Department of Chemistry, Faculty of Science, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Kana Ouchi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.,Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Cheng Tan
- Computational Biophysics Research Team, RIKEN Center for Computational Science, 7-1-26 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Eriko Mano
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Sridhar Mandali
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1737 USA
| | - Yining Wu
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.,Department of Chemistry, Faculty of Science, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Shoji Takada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Satoshi Takahashi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.,Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.,Department of Chemistry, Faculty of Science, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
| | - Reid C Johnson
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1737 USA.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| |
Collapse
|
19
|
A bacteriophage mimic of the bacterial nucleoid-associated protein Fis. Biochem J 2020; 477:1345-1362. [PMID: 32207815 PMCID: PMC7166090 DOI: 10.1042/bcj20200146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/19/2020] [Accepted: 03/24/2020] [Indexed: 11/17/2022]
Abstract
We report the identification and characterization of a bacteriophage λ-encoded protein, NinH. Sequence homology suggests similarity between NinH and Fis, a bacterial nucleoid-associated protein (NAP) involved in numerous DNA topology manipulations, including chromosome condensation, transcriptional regulation and phage site-specific recombination. We find that NinH functions as a homodimer and is able to bind and bend double-stranded DNA in vitro. Furthermore, NinH shows a preference for a 15 bp signature sequence related to the degenerate consensus favored by Fis. Structural studies reinforced the proposed similarity to Fis and supported the identification of residues involved in DNA binding which were demonstrated experimentally. Overexpression of NinH proved toxic and this correlated with its capacity to associate with DNA. NinH is the first example of a phage-encoded Fis-like NAP that likely influences phage excision-integration reactions or bacterial gene expression.
Collapse
|
20
|
DNA binding induces a cis-to- trans switch in Cre recombinase to enable intasome assembly. Proc Natl Acad Sci U S A 2020; 117:24849-24858. [PMID: 32968014 DOI: 10.1073/pnas.2011448117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mechanistic understanding of DNA recombination in the Cre-loxP system has largely been guided by crystallographic structures of tetrameric synaptic complexes. Those studies have suggested a role for protein conformational dynamics that has not been well characterized at the atomic level. We used solution nuclear magnetic resonance (NMR) spectroscopy to discover the link between intrinsic flexibility and function in Cre recombinase. Transverse relaxation-optimized spectroscopy (TROSY) NMR spectra show the N-terminal and C-terminal catalytic domains (CreNTD and CreCat) to be structurally independent. Amide 15N relaxation measurements of the CreCat domain reveal fast-timescale dynamics in most regions that exhibit conformational differences in active and inactive Cre protomers in crystallographic tetramers. However, the C-terminal helix αN, implicated in assembly of synaptic complexes and regulation of DNA cleavage activity via trans protein-protein interactions, is unexpectedly rigid in free Cre. Chemical shift perturbations and intra- and intermolecular paramagnetic relaxation enhancement (PRE) NMR data reveal an alternative autoinhibitory conformation for the αN region of free Cre, wherein it packs in cis over the protein DNA binding surface and active site. Moreover, binding to loxP DNA induces a conformational change that dislodges the C terminus, resulting in a cis-to-trans switch that is likely to enable protein-protein interactions required for assembly of recombinogenic Cre intasomes. These findings necessitate a reexamination of the mechanisms by which this widely utilized gene-editing tool selects target sites, avoids spurious DNA cleavage activity, and controls DNA recombination efficiency.
Collapse
|
21
|
Challenges & opportunities for phage-based in situ microbiome engineering in the gut. J Control Release 2020; 326:106-119. [DOI: 10.1016/j.jconrel.2020.06.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 06/14/2020] [Accepted: 06/15/2020] [Indexed: 12/16/2022]
|
22
|
Abstract
Bacteriophages are the most abundant biological entities in the biosphere and are a source of uncharacterized biological mechanisms and genetic tools. Here, we identify segments of phage genomes that are used for stable extrachromosomal replication in the prophage state. Autonomous replication of some of these phages requires a RepA-like protein, although most lack repA and use RNA-based systems for replication initiation. We describe a suite of plasmids based on these prophage replication functions that vary in copy number, stability, host range, and compatibility. These plasmids expand the toolbox available for genetic manipulation of Mycobacterium and other Actinobacteria, including Gordonia terrae. Temperate bacteriophages are common and establish lysogens of their bacterial hosts in which the prophage is stably inherited. It is typical for such prophages to be integrated into the bacterial chromosome, but extrachromosomally replicating prophages have been described also, with the best characterized being the Escherichia coli phage P1 system. Among the large collection of sequenced mycobacteriophages, more than half are temperate or predicted to be temperate, most of which code for a tyrosine or serine integrase that promotes site-specific prophage integration. However, within the large group of 621 cluster A temperate phages, ∼20% lack an integration cassette, which is replaced with a parABS partitioning system. A subset of these phages carry genes coding for a RepA-like protein (RepA phages), which we show here is necessary and sufficient for autonomous extrachromosomal replication. The non-RepA phages appear to replicate using an RNA-based system, as a parABS-proximal region expressing a noncoding RNA is required for replication. Both RepA and non-RepA phage-based plasmids replicate at one or two copies per cell, transform both Mycobacterium smegmatis and Mycobacterium tuberculosis, and are compatible with pAL5000-derived oriM and integration-proficient plasmid vectors. Characterization of these phage-based plasmids offers insights into the variability of lysogenic maintenance systems and provides a large suite of plasmids for actinobacterial genetics that vary in stability, copy number, compatibility, and host range.
Collapse
|
23
|
Hancock SP, Cascio D, Johnson RC. Cooperative DNA binding by proteins through DNA shape complementarity. Nucleic Acids Res 2019; 47:8874-8887. [PMID: 31616952 PMCID: PMC7145599 DOI: 10.1093/nar/gkz642] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/11/2019] [Accepted: 07/15/2019] [Indexed: 01/13/2023] Open
Abstract
Localized arrays of proteins cooperatively assemble onto chromosomes to control DNA activity in many contexts. Binding cooperativity is often mediated by specific protein-protein interactions, but cooperativity through DNA structure is becoming increasingly recognized as an additional mechanism. During the site-specific DNA recombination reaction that excises phage λ from the chromosome, the bacterial DNA architectural protein Fis recruits multiple λ-encoded Xis proteins to the attR recombination site. Here, we report X-ray crystal structures of DNA complexes containing Fis + Xis, which show little, if any, contacts between the two proteins. Comparisons with structures of DNA complexes containing only Fis or Xis, together with mutant protein and DNA binding studies, support a mechanism for cooperative protein binding solely by DNA allostery. Fis binding both molds the minor groove to potentiate insertion of the Xis β-hairpin wing motif and bends the DNA to facilitate Xis-DNA contacts within the major groove. The Fis-structured minor groove shape that is optimized for Xis binding requires a precisely positioned pyrimidine-purine base-pair step, whose location has been shown to modulate minor groove widths in Fis-bound complexes to different DNA targets.
Collapse
MESH Headings
- Allosteric Site
- Bacteriophage lambda/genetics
- Bacteriophage lambda/metabolism
- Base Sequence
- Binding Sites
- Chromosomes, Bacterial/chemistry
- Chromosomes, Bacterial/metabolism
- Cloning, Molecular
- Crystallography, X-Ray
- DNA Nucleotidyltransferases/chemistry
- DNA Nucleotidyltransferases/genetics
- DNA Nucleotidyltransferases/metabolism
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- DNA, Bacterial/metabolism
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Escherichia coli Proteins/chemistry
- Escherichia coli Proteins/genetics
- Escherichia coli Proteins/metabolism
- Factor For Inversion Stimulation Protein/chemistry
- Factor For Inversion Stimulation Protein/genetics
- Factor For Inversion Stimulation Protein/metabolism
- Gene Expression
- Genetic Vectors/chemistry
- Genetic Vectors/metabolism
- Kinetics
- Models, Molecular
- Nucleic Acid Conformation
- Protein Binding
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Interaction Domains and Motifs
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Recombinational DNA Repair
- Sequence Alignment
- Thermodynamics
- Viral Proteins/chemistry
- Viral Proteins/genetics
- Viral Proteins/metabolism
Collapse
Affiliation(s)
- Stephen P Hancock
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, CA 90095-1737, USA
- Department of Chemistry, Towson University, 8000 York Rd., Towson, MD 21252, USA
| | - Duilio Cascio
- University of California at Los Angeles-Department of Energy Institute of Genomics and Proteomics, University of California at Los Angeles, Los Angeles, CA 90095-1570, USA
| | - Reid C Johnson
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, CA 90095-1737, USA
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, CA 90095, USA
| |
Collapse
|
24
|
Abstract
Mycobacteriophages are viruses that infect mycobacterial hosts. A large number of mycobacteriophages have been isolated and genomically characterized, providing insights into viral diversity and evolution, as well as fueling development of tools for mycobacterial genetics. Mycobacteriophages have intimate relationships with their hosts and provide insights into the genetics and physiology of the mycobacteria and tools for potential clinical applications such as drug development, diagnosis, vaccines, and potentially therapy.
Collapse
|
25
|
Recombination. Mol Biol 2019. [DOI: 10.1016/b978-0-12-813288-3.00027-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
26
|
Li H, Sharp R, Rutherford K, Gupta K, Van Duyne GD. Serine Integrase attP Binding and Specificity. J Mol Biol 2018; 430:4401-4418. [PMID: 30227134 DOI: 10.1016/j.jmb.2018.09.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/07/2018] [Accepted: 09/11/2018] [Indexed: 01/31/2023]
Abstract
Serine integrases catalyze the site-specific insertion of viral DNA into a host's genome. The minimal requirements and irreversible nature of this integration reaction have led to the use of serine integrases in applications ranging from bacterial memory storage devices to gene therapy. Our understanding of how the integrase proteins recognize the viral (attP) and host (attB) attachment sites is limited, with structural data available for only a Listeria integrase C-terminal domain (CTD) bound to an attP half-site. Here we report quantitative binding and saturation mutagenesis analyses for the Listeria innocua prophage attP site and a new 2.8-Å crystal structure of the CTD•attP half site. We find that Int binds with high affinity to attP (6.9 nM), but the Int CTD binds to attP half-sites with only 7- to 10-fold lower affinity, supporting the idea that free energy is expended to open an Int dimer for attP binding. Despite the 50-bp Int-attP interaction surface, only 20 residues are sensitive to mutagenesis, and of these, only 6 require a specific residue for efficient Int binding and integration activity. One of the integrase DNA-binding domains, the recombinase domain, appears to be primarily non-specific. Several substitutions result in an improved attP site, indicating that higher-efficiency attachment sites can be obtained through site engineering. These findings advance our understanding of serine integrase function and provide important data for efforts towards engineering this family of enzymes for a variety of biotechnology applications.
Collapse
Affiliation(s)
- Huiguang Li
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert Sharp
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Karen Rutherford
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kushol Gupta
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gregory D Van Duyne
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
27
|
Nonaka L, Yamamoto T, Maruyama F, Hirose Y, Onishi Y, Kobayashi T, Suzuki S, Nomura N, Masuda M, Yano H. Interplay of a non-conjugative integrative element and a conjugative plasmid in the spread of antibiotic resistance via suicidal plasmid transfer from an aquaculture Vibrio isolate. PLoS One 2018; 13:e0198613. [PMID: 29879198 PMCID: PMC5991714 DOI: 10.1371/journal.pone.0198613] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 05/22/2018] [Indexed: 12/01/2022] Open
Abstract
The capture of antimicrobial resistance genes (ARGs) by mobile genetic elements (MGEs) plays a critical role in resistance acquisition for human-associated bacteria. Although aquaculture environments are recognized as important reservoirs of ARGs, intra- and intercellular mobility of MGEs discovered in marine organisms is poorly characterized. Here, we show a new pattern of interspecies ARGs transfer involving a 'non-conjugative' integrative element. To identify active MGEs in a Vibrio ponticus isolate, we conducted whole-genome sequencing of a transconjugant obtained by mating between Escherichia coli and Vibrio ponticus. This revealed integration of a plasmid (designated pSEA1) into the chromosome, consisting of a self-transmissible plasmid backbone of the MOBH group, ARGs, and a 13.8-kb integrative element Tn6283. Molecular genetics analysis suggested a two-step gene transfer model. First, Tn6283 integrates into the recipient chromosome during suicidal plasmid transfer, followed by homologous recombination between the Tn6283 copy in the chromosome and that in the newly transferred pSEA1. Tn6283 is unusual among integrative elements in that it apparently does not encode transfer function and its excision barely generates unoccupied donor sites. Thus, its movement is analogous to the transposition of insertion sequences rather than to that of canonical integrative and conjugative elements. Overall, this study reveals the presence of a previously unrecognized type of MGE in a marine organism, highlighting diversity in the mode of interspecies gene transfer.
Collapse
Affiliation(s)
- Lisa Nonaka
- Department of Microbiology, Dokkyo Medical University School of Medicine, Mibu, Tochigi, Japan
| | - Tatsuya Yamamoto
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Japan
| | | | - Yuu Hirose
- Department of Environmental and Life Sciences, Toyohashi University of Technology, Tempaku, Toyohashi, Aichi, Japan
| | - Yuki Onishi
- Center for Marine Environmental Studies, Ehime University, Matsuyama, Ehime, Japan
| | | | - Satoru Suzuki
- Center for Marine Environmental Studies, Ehime University, Matsuyama, Ehime, Japan
| | - Nobuhiko Nomura
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Japan
| | - Michiaki Masuda
- Department of Microbiology, Dokkyo Medical University School of Medicine, Mibu, Tochigi, Japan
| | - Hirokazu Yano
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Japan
| |
Collapse
|
28
|
Castillo A, Tello M, Ringwald K, Acuña LG, Quatrini R, Orellana O. A DNA segment encoding the anticodon stem/loop of tRNA determines the specific recombination of integrative-conjugative elements in Acidithiobacillus species. RNA Biol 2017; 15:492-499. [PMID: 29168417 DOI: 10.1080/15476286.2017.1408765] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Horizontal gene transfer is crucial for the adaptation of microorganisms to environmental cues. The acidophilic, bioleaching bacterium Acidithiobacillus ferrooxidans encodes an integrative-conjugative genetic element (ICEAfe1) inserted in the gene encoding a tRNAAla. This genetic element is actively excised from the chromosome upon induction of DNA damage. A similar genetic element (ICEAcaTY.2) is also found in an equivalent position in the genome of Acidithiobacillus caldus. The local genomic context of both mobile genetic elements is highly syntenous and the cognate integrases are well conserved. By means of site directed mutagenesis, target site deletions and in vivo integrations assays in the heterologous model Escherichia coli, we assessed the target sequence requirements for site-specific recombination to be catalyzed by these integrases. We determined that each enzyme recognizes a specific small DNA segment encoding the anticodon stem/loop of the tRNA as target site and that specific positions in these regions are well conserved in the target attB sites of orthologous integrases. Also, we demonstrate that the local genetic context of the target sequence is not relevant for the integration to take place. These findings shed new light on the mechanism of site-specific integration of integrative-conjugative elements in members of Acidithiobacillus genus.
Collapse
Affiliation(s)
- Andrés Castillo
- a Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina , Universidad de Chile , Santiago , Región Metropolitana , Chile
| | - Mario Tello
- b Centro de Biotecnología Acuícola, Departamento de Biología, Facultad de Química y Biología , Universidad de Santiago de Chile , Santiago , Chile
| | - Kenneth Ringwald
- c Carl R. Woese Institute for Genomic Biology, Department of Microbiology , University of Illinois , Urbana-Champaign , Illinois , United States
| | - Lillian G Acuña
- d Fundación Ciencia y Vida. Ave. Zañartu 1482 - Ñuñoa, Santiago , Región Metropolitana , Chile
| | - Raquel Quatrini
- d Fundación Ciencia y Vida. Ave. Zañartu 1482 - Ñuñoa, Santiago , Región Metropolitana , Chile
| | - Omar Orellana
- a Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina , Universidad de Chile , Santiago , Región Metropolitana , Chile
| |
Collapse
|
29
|
Gupta K, Sharp R, Yuan JB, Li H, Van Duyne GD. Coiled-coil interactions mediate serine integrase directionality. Nucleic Acids Res 2017; 45:7339-7353. [PMID: 28549184 PMCID: PMC5499577 DOI: 10.1093/nar/gkx474] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 05/15/2017] [Indexed: 11/14/2022] Open
Abstract
Serine integrases are bacteriophage enzymes that carry out site-specific integration and excision of their viral genomes. The integration reaction is highly directional; recombination between the phage attachment site attP and the host attachment site attB to form the hybrid sites attL and attR is essentially irreversible. In a recent model, extended coiled-coil (CC) domains in the integrase subunits are proposed to interact in a way that favors the attPxattB reaction but inhibits the attLxattR reaction. Here, we show for the Listeria innocua integrase (LI Int) system that the CC domain promotes self-interaction in isolated Int and when Int is bound to attachment sites. Three independent crystal structures of the CC domain reveal the molecular nature of the CC dimer interface. Alanine substitutions of key residues in the interface support the functional significance of the structural model and indicate that the same interaction is responsible for promoting integration and for inhibiting excision. An updated model of a LI Int•attL complex that incorporates the high resolution CC dimer structure provides insights that help to explain the unusual CC dimer structure and potential sources of stability in Int•attL and Int•attR complexes. Together, the data provide a molecular basis for understanding serine integrase directionality.
Collapse
MESH Headings
- Amino Acid Sequence
- Attachment Sites, Microbiological
- Bacteriophages/genetics
- Bacteriophages/metabolism
- Binding Sites
- Cloning, Molecular
- Crystallography, X-Ray
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- DNA, Bacterial/metabolism
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Gene Expression
- Integrases/chemistry
- Integrases/genetics
- Integrases/metabolism
- Kinetics
- Listeria/genetics
- Listeria/metabolism
- Listeria/virology
- Models, Molecular
- Mutagenesis, Insertional
- Protein Binding
- Protein Conformation, alpha-Helical
- Protein Interaction Domains and Motifs
- Protein Multimerization
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Recombination, Genetic
- Sequence Alignment
- Sequence Homology, Amino Acid
- Serine/chemistry
- Serine/metabolism
- Substrate Specificity
- Thermodynamics
- Viral Proteins/chemistry
- Viral Proteins/genetics
- Viral Proteins/metabolism
Collapse
Affiliation(s)
- Kushol Gupta
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 10104, USA
| | - Robert Sharp
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 10104, USA
| | - Jimmy B. Yuan
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 10104, USA
| | - Huiguang Li
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 10104, USA
| | - Gregory D. Van Duyne
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 10104, USA
- To whom correspondence should be addressed. Tel: +1 215 898 3058;
| |
Collapse
|
30
|
Bowyer JE, Hsiao V, Wong WW, Bates DG. Mechanistic modelling of a recombinase‐based two‐input temporal logic gate. ENGINEERING BIOLOGY 2017. [DOI: 10.1049/enb.2017.0006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- Jack E. Bowyer
- Warwick Integrative Synthetic Biology Centre, School of Engineering University of Warwick Coventry CV4 7AL UK
| | - Victoria Hsiao
- Biology and Biological Engineering California Institute of Technology Pasadena CA 91125 USA
| | - Wilson W. Wong
- Department of Biomedical Engineering Boston University Boston MA 02215 USA
| | - Declan G. Bates
- Warwick Integrative Synthetic Biology Centre, School of Engineering University of Warwick Coventry CV4 7AL UK
| |
Collapse
|
31
|
Abstract
One of the major mechanisms driving the evolution of all organisms is genomic rearrangement. In hyperthermophilic Archaea of the order Thermococcales, large chromosomal inversions occur so frequently that even closely related genomes are difficult to align. Clearly not resulting from the native homologous recombination machinery, the causative agent of these inversions has remained elusive. We present a model in which genomic inversions are catalyzed by the integrase enzyme encoded by a family of mobile genetic elements. We characterized the integrase from Thermococcus nautili plasmid pTN3 and showed that besides canonical site-specific reactions, it catalyzes low sequence specificity recombination reactions with the same outcome as homologous recombination events on DNA segments as short as 104bp both in vitro and in vivo, in contrast to other known tyrosine recombinases. Through serial culturing, we showed that the integrase-mediated divergence of T. nautili strains occurs at an astonishing rate, with at least four large-scale genomic inversions appearing within 60 generations. Our results and the ubiquitous distribution of pTN3-like integrated elements suggest that a major mechanism of evolution of an entire order of Archaea results from the activity of a selfish mobile genetic element. Mobile elements (MEs) such as viruses, plasmids and transposons infect most living organisms and often encode recombinases promoting their insertion into cellular genomes. These insertions alter the genome of their host according to two main mechanisms. First, MEs provide new functions to the cell by integrating their own genetic information into the DNA of the host, at one or more locations. Secondly, cellular homologous recombination will act upon multiple integrated copies and produce a variety of large-scale chromosomal rearrangements. If such modifications are advantageous, they will spread into the population by natural selection. Typically, enzymes involved in cellular homologous recombination and the integration of MEs are distinct. We describe here a novel plasmid-encoded archaeal integrase which in addition to site-specific recombination can catalyze low sequence specificity recombination reactions akin to homologous recombination.
Collapse
|
32
|
Bowyer J, Zhao J, Subsoontorn P, Wong W, Rosser S, Bates D. Mechanistic Modeling of a Rewritable Recombinase Addressable Data Module. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2016; 10:1161-1170. [PMID: 27244749 DOI: 10.1109/tbcas.2016.2526668] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Many of the most important applications predicted to arise from Synthetic Biology will require engineered cellular memory with the capability to store data in a rewritable and reversible manner upon induction by transient stimuli. DNA recombination provides an ideal platform for cellular data storage and has allowed the development of a rewritable recombinase addressable data (RAD) module, capable of efficient data storage within a chromosome. Here, we develop the first detailed mechanistic model of DNA recombination, and validate it against a new set of in vitro data on recombination efficiencies across a range of different concentrations of integrase and gp3. Investigation of in vivo recombination dynamics using our model reveals the importance of fully accounting for all mechanistic features of DNA recombination in order to accurately predict the effect of different switching strategies on RAD module performance, and highlights its usefulness as a design tool for building future synthetic circuitry.
Collapse
|
33
|
Dorman CJ, Bogue MM. The interplay between DNA topology and accessory factors in site-specific recombination in bacteria and their bacteriophages. Sci Prog 2016; 99:420-437. [PMID: 28742481 PMCID: PMC10365484 DOI: 10.3184/003685016x14811202974921] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Site-specific recombination is employed widely in bacteria and bacteriophage as a basis for genetic switching events that control phenotypic variation. It plays a vital role in the life cycles of phages and in the replication cycles of chromosomes and plasmids in bacteria. Site-specific recombinases drive these processes using very short segments of identical (or nearly identical) DNA sequences. In some cases, the efficiencies of the recombination reactions are modulated by the topological state of the participating DNA sequences and by the availability of accessory proteins that shape the DNA. These dependencies link the molecular machines that conduct the recombination reactions to the physiological state of the cell. This is because the topological state of bacterial DNA varies constantly during the growth cycle and so does the availability of the accessory factors. In addition, some accessory factors are under allosteric control by metabolic products or second messengers that report the physiological status of the cell. The interplay between DNA topology, accessory factors and site-specific recombination provides a powerful illustration of the connectedness and integration of molecular events in bacterial cells and in viruses that parasitise bacterial cells.
Collapse
Affiliation(s)
| | - Marina M. Bogue
- Natural Science (Microbiology) from Trinity College Dublin, Ireland
| |
Collapse
|
34
|
Laxmikanthan G, Xu C, Brilot AF, Warren D, Steele L, Seah N, Tong W, Grigorieff N, Landy A, Van Duyne GD. Structure of a Holliday junction complex reveals mechanisms governing a highly regulated DNA transaction. eLife 2016; 5. [PMID: 27223329 PMCID: PMC4880445 DOI: 10.7554/elife.14313] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 04/07/2016] [Indexed: 11/13/2022] Open
Abstract
The molecular machinery responsible for DNA expression, recombination, and compaction has been difficult to visualize as functionally complete entities due to their combinatorial and structural complexity. We report here the structure of the intact functional assembly responsible for regulating and executing a site-specific DNA recombination reaction. The assembly is a 240-bp Holliday junction (HJ) bound specifically by 11 protein subunits. This higher-order complex is a key intermediate in the tightly regulated pathway for the excision of bacteriophage λ viral DNA out of the E. coli host chromosome, an extensively studied paradigmatic model system for the regulated rearrangement of DNA. Our results provide a structural basis for pre-existing data describing the excisive and integrative recombination pathways, and they help explain their regulation. DOI:http://dx.doi.org/10.7554/eLife.14313.001 Some viruses can remain dormant inside an infected cell and only become active when conditions are right to multiply and infect other cells. Bacteriophage λ is a much-studied model virus that adopts this lifecycle by inserting its genetic information into the chromosome of a bacterium called Escherichia coli. Certain signals can later trigger the viral DNA to be removed from the bacterial chromosome, often after many generations, so that it can replicate and make new copies of the virus. Specific sites on the viral and bacterial DNA earmark where the virus’s genetic information will insert and how it will be removed. Remarkably, each of these two site-specific reactions (i.e. insertion and removal) cannot be reversed once started, and their onset is precisely controlled. These reactions involve a molecular machine or complex that consists of four enzymes that cut and reconnect the DNA strands and seven DNA-bending proteins that bring distant sites closer together. Despite decades of work by many laboratories, no one had provided a three-dimensional image of this complete molecular machine together with the DNA it acts upon. Now, Laxmikanthan et al. reveal a three-dimensional structure of this machine with all its components by trapping and purifying the complex at the halfway point in the removal process, when the DNA forms a structure known as a “Holliday junction”. The structure was obtained using electron microscopy of complexes frozen in ice. The structure answers many of the long-standing questions about the removal and insertion reactions. For example, it shows how the DNA-bending proteins and enzymes assemble into a large complex to carry out the removal reaction, which is different from the complex that carries out the insertion reaction. It also shows that the removal and insertion reactions are each prevented from acting in the opposite direction because the two complexes have different requirements. These new findings improve our understanding of how the insertion and removal reactions are precisely regulated. Laxmikanthan et al.’s results also serve as examples for thinking about the complicated regulatory machines that are widespread in biology. DOI:http://dx.doi.org/10.7554/eLife.14313.002
Collapse
Affiliation(s)
- Gurunathan Laxmikanthan
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, United States.,Division of Biology and Medicine, Brown University, Providence, United States
| | - Chen Xu
- Department of Biochemistry, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, United States
| | - Axel F Brilot
- Department of Biochemistry, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, United States
| | - David Warren
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, United States.,Division of Biology and Medicine, Brown University, Providence, United States
| | - Lindsay Steele
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, United States.,Division of Biology and Medicine, Brown University, Providence, United States
| | - Nicole Seah
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, United States.,Division of Biology and Medicine, Brown University, Providence, United States
| | - Wenjun Tong
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, United States.,Division of Biology and Medicine, Brown University, Providence, United States
| | - Nikolaus Grigorieff
- Department of Biochemistry, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, United States.,Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Arthur Landy
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, United States.,Division of Biology and Medicine, Brown University, Providence, United States
| | - Gregory D Van Duyne
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| |
Collapse
|
35
|
Meinke G, Bohm A, Hauber J, Pisabarro MT, Buchholz F. Cre Recombinase and Other Tyrosine Recombinases. Chem Rev 2016; 116:12785-12820. [PMID: 27163859 DOI: 10.1021/acs.chemrev.6b00077] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tyrosine-type site-specific recombinases (T-SSRs) have opened new avenues for the predictable modification of genomes as they enable precise genome editing in heterologous hosts. These enzymes are ubiquitous in eubacteria, prevalent in archaea and temperate phages, present in certain yeast strains, but barely found in higher eukaryotes. As tools they find increasing use for the generation and systematic modification of genomes in a plethora of organisms. If applied in host organisms, they enable precise DNA cleavage and ligation without the gain or loss of nucleotides. Criteria directing the choice of the most appropriate T-SSR system for genetic engineering include that, whenever possible, the recombinase should act independent of cofactors and that the target sequences should be long enough to be unique in a given genome. This review is focused on recent advancements in our mechanistic understanding of simple T-SSRs and their application in developmental and synthetic biology, as well as in biomedical research.
Collapse
Affiliation(s)
- Gretchen Meinke
- Department of Developmental, Molecular & Chemical Biology, Tufts University School of Medicine , Boston, Massachusetts 02111, United States
| | - Andrew Bohm
- Department of Developmental, Molecular & Chemical Biology, Tufts University School of Medicine , Boston, Massachusetts 02111, United States
| | - Joachim Hauber
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology , 20251 Hamburg, Germany
| | | | - Frank Buchholz
- Medical Systems Biology, UCC, Medical Faculty Carl Gustav Carus TU Dresden , 01307 Dresden, Germany
| |
Collapse
|
36
|
Lunt BL, Hatfull GF. Brujita Integrase: A Simple, Arm-Less, Directionless, and Promiscuous Tyrosine Integrase System. J Mol Biol 2016; 428:2289-2306. [PMID: 27113630 DOI: 10.1016/j.jmb.2016.04.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 04/13/2016] [Accepted: 04/15/2016] [Indexed: 11/29/2022]
Abstract
Mycobacteriophage Brujita is an unusual temperate phage in which establishment of superinfection immunity is dependent on chromosomal integration. Integration is mediated by a non-canonical tyrosine integrase (Int) lacking an N-terminal domain typically associated with binding to arm-type sites within the phage attachment site (attP). This raises the question as to how these Ints bind their DNA substrates, if they form higher-order protein DNA complexes, and how site selection and recombinational directionality are determined. Here we show that Brujita Int is a simple recombinase, whose properties more closely resemble those of FLP and Cre than it does the canonical phage Ints. Brujita Int uses relatively small DNA substrates, fails to discriminate between attP and attB, cleaves attachment site DNA to form a 6-base overlap region, and lacks directional control. Brujita Int also has an unusual pattern of binding to its DNA substrates. It binds to two half sites (B and B') at attB, although binding to the B half site is strongly dependent on occupancy of B'. In contrast, binding to the P half site is not observed, even when Int is bound at P'. However, an additional Int binding site (P1) is displaced to the left of the crossover site at attP, is required for recombination and is predicted to facilitate binding of Int to the P half site during synapsis. These simple phage Int systems may reflect ancestral states of phage evolution with the complexities of higher-order complex formation and directional control representing subsequent adaptations.
Collapse
Affiliation(s)
- Bryce L Lunt
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Graham F Hatfull
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| |
Collapse
|
37
|
Unmasking the ancestral activity of integron integrases reveals a smooth evolutionary transition during functional innovation. Nat Commun 2016; 7:10937. [PMID: 26961432 PMCID: PMC4792948 DOI: 10.1038/ncomms10937] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 02/03/2016] [Indexed: 12/28/2022] Open
Abstract
Tyrosine (Y)-recombinases have evolved to deliver mechanistically different reactions on a variety of substrates, but these evolutionary transitions are poorly understood. Among them, integron integrases are hybrid systems recombining single- and double-stranded DNA partners. These reactions are asymmetric and need a replicative resolution pathway, an exception to the canonical second strand exchange model of Y-recombinases. Integron integrases possess a specific domain for this specialized pathway. Here we show that despite this, integrases are still capable of efficiently operating the ancestral second strand exchange in symmetrical reactions between double-stranded substrates. During these reactions, both strands are reactive and Holliday junction resolution can follow either pathway. A novel deep-sequencing approach allows mapping of the crossover point for the second strand exchange. The persistence of the ancestral activity in integrases illustrates their robustness and shows that innovation towards new recombination substrates and resolution pathways was a smooth evolutionary process. The integron integrases have evolved to perform recombination of single and double stranded DNA. Here the authors show that the ancestral pathway is still functional at double stranded sites, revealing the evolution towards the modern resolution pathway.
Collapse
|
38
|
Hancock SP, Stella S, Cascio D, Johnson RC. DNA Sequence Determinants Controlling Affinity, Stability and Shape of DNA Complexes Bound by the Nucleoid Protein Fis. PLoS One 2016; 11:e0150189. [PMID: 26959646 PMCID: PMC4784862 DOI: 10.1371/journal.pone.0150189] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 01/28/2016] [Indexed: 11/18/2022] Open
Abstract
The abundant Fis nucleoid protein selectively binds poorly related DNA sequences with high affinities to regulate diverse DNA reactions. Fis binds DNA primarily through DNA backbone contacts and selects target sites by reading conformational properties of DNA sequences, most prominently intrinsic minor groove widths. High-affinity binding requires Fis-stabilized DNA conformational changes that vary depending on DNA sequence. In order to better understand the molecular basis for high affinity site recognition, we analyzed the effects of DNA sequence within and flanking the core Fis binding site on binding affinity and DNA structure. X-ray crystal structures of Fis-DNA complexes containing variable sequences in the noncontacted center of the binding site or variations within the major groove interfaces show that the DNA can adapt to the Fis dimer surface asymmetrically. We show that the presence and position of pyrimidine-purine base steps within the major groove interfaces affect both local DNA bending and minor groove compression to modulate affinities and lifetimes of Fis-DNA complexes. Sequences flanking the core binding site also modulate complex affinities, lifetimes, and the degree of local and global Fis-induced DNA bending. In particular, a G immediately upstream of the 15 bp core sequence inhibits binding and bending, and A-tracts within the flanking base pairs increase both complex lifetimes and global DNA curvatures. Taken together, our observations support a revised DNA motif specifying high-affinity Fis binding and highlight the range of conformations that Fis-bound DNA can adopt. The affinities and DNA conformations of individual Fis-DNA complexes are likely to be tailored to their context-specific biological functions.
Collapse
Affiliation(s)
- Stephen P. Hancock
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, California, United States of America
| | - Stefano Stella
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, California, United States of America
| | - Duilio Cascio
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, California, United States of America
- Department of Energy Institute of Genomics and Proteomics, University of California at Los Angeles, Los Angeles, California, United States of America
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California, United States of America
| | - Reid C. Johnson
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, California, United States of America
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California, United States of America
- * E-mail:
| |
Collapse
|
39
|
Vijaya Chandra SH, Makhija H, Peter S, Myint Wai CM, Li J, Zhu J, Ren Z, D'Alcontres MS, Siau JW, Chee S, Ghadessy FJ, Dröge P. Conservative site-specific and single-copy transgenesis in human LINE-1 elements. Nucleic Acids Res 2015; 44:e55. [PMID: 26673710 PMCID: PMC4824084 DOI: 10.1093/nar/gkv1345] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 11/17/2015] [Indexed: 12/22/2022] Open
Abstract
Genome engineering of human cells plays an important role in biotechnology and molecular medicine. In particular, insertions of functional multi-transgene cassettes into suitable endogenous sequences will lead to novel applications. Although several tools have been exploited in this context, safety issues such as cytotoxicity, insertional mutagenesis and off-target cleavage together with limitations in cargo size/expression often compromise utility. Phage λ integrase (Int) is a transgenesis tool that mediates conservative site-specific integration of 48 kb DNA into a safe harbor site of the bacterial genome. Here, we show that an Int variant precisely recombines large episomes into a sequence, term edattH4X, found in 1000 human Long INterspersed Elements-1 (LINE-1). We demonstrate single-copy transgenesis through attH4X-targeting in various cell lines including hESCs, with the flexibility of selecting clones according to transgene performance and downstream applications. This is exemplified with pluripotency reporter cassettes and constitutively expressed payloads that remain functional in LINE1-targeted hESCs and differentiated progenies. Furthermore, LINE-1 targeting does not induce DNA damage-response or chromosomal aberrations, and neither global nor localized endogenous gene expression is substantially affected. Hence, this simple transgene addition tool should become particularly useful for applications that require engineering of the human genome with multi-transgenes.
Collapse
Affiliation(s)
| | - Harshyaa Makhija
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Sabrina Peter
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Cho Mar Myint Wai
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Jinming Li
- Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Tonghe GuangZhou 510515, People's Republic of China State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Tonghe, Guangzhou 510515, People's Republic of China
| | - Jindong Zhu
- Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Tonghe GuangZhou 510515, People's Republic of China State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Tonghe, Guangzhou 510515, People's Republic of China
| | - Zhonglu Ren
- Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Tonghe GuangZhou 510515, People's Republic of China State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Tonghe, Guangzhou 510515, People's Republic of China
| | | | - Jia Wei Siau
- p53Lab, Agency for Science Technology and Research, Singapore 138673
| | - Sharon Chee
- p53Lab, Agency for Science Technology and Research, Singapore 138673
| | | | - Peter Dröge
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| |
Collapse
|