1
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de la Gándara Á, Spínola-Amilibia M, Araújo-Bazán L, Núñez-Ramírez R, Berger JM, Arias-Palomo E. Molecular basis for transposase activation by a dedicated AAA+ ATPase. Nature 2024; 630:1003-1011. [PMID: 38926614 PMCID: PMC11208146 DOI: 10.1038/s41586-024-07550-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 05/09/2024] [Indexed: 06/28/2024]
Abstract
Transposases drive chromosomal rearrangements and the dissemination of drug-resistance genes and toxins1-3. Although some transposases act alone, many rely on dedicated AAA+ ATPase subunits that regulate site selectivity and catalytic function through poorly understood mechanisms. Using IS21 as a model transposase system, we show how an ATPase regulator uses nucleotide-controlled assembly and DNA deformation to enable structure-based site selectivity, transposase recruitment, and activation and integration. Solution and cryogenic electron microscopy studies show that the IstB ATPase self-assembles into an autoinhibited pentamer of dimers that tightly curves target DNA into a half-coil. Two of these decamers dimerize, which stabilizes the target nucleic acid into a kinked S-shaped configuration that engages the IstA transposase at the interface between the two IstB oligomers to form an approximately 1 MDa transpososome complex. Specific interactions stimulate regulator ATPase activity and trigger a large conformational change on the transposase that positions the catalytic site to perform DNA strand transfer. These studies help explain how AAA+ ATPase regulators-which are used by classical transposition systems such as Tn7, Mu and CRISPR-associated elements-can remodel their substrate DNA and cognate transposases to promote function.
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Affiliation(s)
| | | | - Lidia Araújo-Bazán
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
| | | | - James M Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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2
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Senavirathne G, London J, Gardner A, Fishel R, Yoder KE. DNA strand breaks and gaps target retroviral intasome binding and integration. Nat Commun 2023; 14:7072. [PMID: 37923737 PMCID: PMC10624929 DOI: 10.1038/s41467-023-42641-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 10/17/2023] [Indexed: 11/06/2023] Open
Abstract
Retrovirus integration into a host genome is essential for productive infections. The integration strand transfer reaction is catalyzed by a nucleoprotein complex (Intasome) containing the viral integrase (IN) and the reverse transcribed (RT) copy DNA (cDNA). Previous studies suggested that DNA target-site recognition limits intasome integration. Using single molecule Förster resonance energy transfer (smFRET), we show prototype foamy virus (PFV) intasomes specifically bind to DNA strand breaks and gaps. These break and gap DNA discontinuities mimic oxidative base excision repair (BER) lesion-processing intermediates that have been shown to affect retrovirus integration in vivo. The increased DNA binding events targeted strand transfer to the break/gap site without inducing substantial intasome conformational changes. The major oxidative BER substrate 8-oxo-guanine as well as a G/T mismatch or +T nucleotide insertion that typically introduce a bend or localized flexibility into the DNA, did not increase intasome binding or targeted integration. These results identify DNA breaks or gaps as modulators of dynamic intasome-target DNA interactions that encourage site-directed integration.
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Affiliation(s)
- Gayan Senavirathne
- Department of Cancer Biology and Genetics, The Ohio State University College of Medicine, Columbus, OH, 43210, USA
| | - James London
- Department of Cancer Biology and Genetics, The Ohio State University College of Medicine, Columbus, OH, 43210, USA
| | - Anne Gardner
- Department of Cancer Biology and Genetics, The Ohio State University College of Medicine, Columbus, OH, 43210, USA
| | - Richard Fishel
- Department of Cancer Biology and Genetics, The Ohio State University College of Medicine, Columbus, OH, 43210, USA.
- Molecular Carcinogenesis and Chemoprevention Program, The James Comprehensive Cancer Center and Ohio State University, Columbus, OH, 43210, USA.
| | - Kristine E Yoder
- Department of Cancer Biology and Genetics, The Ohio State University College of Medicine, Columbus, OH, 43210, USA.
- Molecular Carcinogenesis and Chemoprevention Program, The James Comprehensive Cancer Center and Ohio State University, Columbus, OH, 43210, USA.
- Center for Retrovirus Research, The Ohio State University, Columbus, OH, 43210, USA.
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3
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Zeng T, Yin J, Liu Z, Li Z, Zhang Y, Lv Y, Lu ML, Luo M, Chen M, Xiao Y. Mechanistic insights into transposon cleavage and integration by TnsB of ShCAST system. Cell Rep 2023; 42:112698. [PMID: 37379212 DOI: 10.1016/j.celrep.2023.112698] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 04/02/2023] [Accepted: 06/09/2023] [Indexed: 06/30/2023] Open
Abstract
The type V-K CRISPR-associated transposons (CASTs) allow RNA-guided DNA integration and have great potential as a programmable site-specific gene insertion tool. Although all core components have been independently characterized structurally, the mechanism of how the transposase TnsB associates with AAA+ ATPase TnsC and catalyzes donor DNA cleavage and integration remains ambiguous. In this study, we demonstrate that TniQ-dCas9 fusion can direct site-specific transposition by TnsB/TnsC in ShCAST. TnsB is a 3'-5' exonuclease that specifically cleaves donor DNA at the end of the terminal repeats and integrates the left end prior to the right end. The nucleotide preference and the cleavage site of TnsB are markedly different from those of the well-documented MuA. We also find that TnsB/TnsC association is enhanced in a half-integration state. Overall, our results provide valuable insights into the mechanism and application expansion of CRISPR-mediated site-specific transposition by TnsB/TnsC.
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Affiliation(s)
- Ting Zeng
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Jie Yin
- Department of Biochemistry, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Ziwen Liu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Zhaoxing Li
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Yu Zhang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Yang Lv
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Mei-Ling Lu
- Department of Biochemistry, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Min Luo
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Meirong Chen
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
| | - Yibei Xiao
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China; Chongqing Innovation Institute of China Pharmaceutical University, Chongqing 401135, China.
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4
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Fernandez M, Shkumatov AV, Liu Y, Stulemeijer C, Derclaye S, Efremov R, Hallet B, Alsteens D. AFM-based force spectroscopy unravels stepwise formation of the DNA transposition complex in the widespread Tn3 family mobile genetic elements. Nucleic Acids Res 2023; 51:4929-4941. [PMID: 37026471 PMCID: PMC10250215 DOI: 10.1093/nar/gkad241] [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: 12/21/2022] [Revised: 03/03/2023] [Accepted: 03/23/2023] [Indexed: 04/08/2023] Open
Abstract
Transposon Tn4430 belongs to a widespread family of bacterial transposons, the Tn3 family, which plays a prevalent role in the dissemination of antibiotic resistance among pathogens. Despite recent data on the structural architecture of the transposition complex, the molecular mechanisms underlying the replicative transposition of these elements are still poorly understood. Here, we use force-distance curve-based atomic force microscopy to probe the binding of the TnpA transposase of Tn4430 to DNA molecules containing one or two transposon ends and to extract the thermodynamic and kinetic parameters of transposition complex assembly. Comparing wild-type TnpA with previously isolated deregulated TnpA mutants supports a stepwise pathway for transposition complex formation and activation during which TnpA first binds as a dimer to a single transposon end and then undergoes a structural transition that enables it to bind the second end cooperatively and to become activated for transposition catalysis, the latter step occurring at a much faster rate for the TnpA mutants. Our study thus provides an unprecedented approach to probe the dynamic of a complex DNA processing machinery at the single-particle level.
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Affiliation(s)
- Maricruz Fernandez
- NanoBioPhysics lab, Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
- Biochemistry and Genetics of Microorganisms, Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Alexander V Shkumatov
- Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Yun Liu
- Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Claire Stulemeijer
- Biochemistry and Genetics of Microorganisms, Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Sylvie Derclaye
- NanoBioPhysics lab, Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Rouslan G Efremov
- Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Bernard Hallet
- Biochemistry and Genetics of Microorganisms, Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - David Alsteens
- NanoBioPhysics lab, Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
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5
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Smiley AT, Tompkins KJ, Pawlak MR, Krueger AJ, Evans RL, Shi K, Aihara H, Gordon WR. Watson-Crick Base-Pairing Requirements for ssDNA Recognition and Processing in Replication-Initiating HUH Endonucleases. mBio 2023; 14:e0258722. [PMID: 36541758 PMCID: PMC9973303 DOI: 10.1128/mbio.02587-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Replication-initiating HUH endonucleases (Reps) are sequence-specific nucleases that cleave and rejoin single-stranded DNA (ssDNA) during rolling-circle replication. These functions are mediated by covalent linkage of the Rep to its substrate post cleavage. Here, we describe the structures of the endonuclease domain from the Muscovy duck circovirus Rep in complex with its cognate ssDNA 10-mer with and without manganese in the active site. Structural and functional analyses demonstrate that divalent cations play both catalytic and structural roles in Reps by polarizing and positioning their substrate. Further structural comparisons highlight the importance of an intramolecular substrate Watson-Crick (WC) base pairing between the -4 and +1 positions. Subsequent kinetic and functional analyses demonstrate a functional dependency on WC base pairing between these positions regardless of the pair's identity (i.e., A·T, T·A, G·C, or C·G), highlighting a structural specificity for substrate interaction. Finally, considering how well WC swaps were tolerated in vitro, we sought to determine to what extent the canonical -4T·+1A pairing is conserved in circular Rep-encoding single-stranded DNA viruses and found evidence of noncanonical pairings in a minority of these genomes. Altogether, our data suggest that substrate intramolecular WC base pairing is a universal requirement for separation and reunion of ssDNA in Reps. IMPORTANCE Circular Rep-encoding single-stranded DNA (CRESS-DNA) viruses are a ubiquitous group of viruses that infect organisms across all domains of life. These viruses negatively impact both agriculture and human health. All members of this viral family employ a multifunctional nuclease (Rep) to initiate replication. Reps are structurally similar throughout this family, making them targets of interest for viral inhibition strategies. Here, we investigate the functional dependencies of the Rep protein from Muscovy duck circovirus for ssDNA interaction. We demonstrate that this Rep requires an intramolecular Watson-Crick base pairing for origin of replication (Ori) recognition and interaction. We show that noncognate base pair swaps are well tolerated, highlighting a local structural specificity over sequence specificity. Bioinformatic analysis found that the vast majority of CRESS-DNA Oris form base pairs in conserved positions, suggesting this pairing is a universal requirement for replication initiation in the CRESS-DNA virus family.
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Affiliation(s)
- Adam T. Smiley
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Kassidy J. Tompkins
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Matthew R. Pawlak
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - August J. Krueger
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Robert L. Evans
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Ke Shi
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Wendy R. Gordon
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
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6
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First full views of a CRISPR-guided system for gene insertion. Nature 2023; 613:634-635. [PMID: 36631579 DOI: 10.1038/d41586-022-04584-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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7
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Ten TB, Zvoda V, Sarangi MK, Kuznetsov SV, Ansari A. "Flexible hinge" dynamics in mismatched DNA revealed by fluorescence correlation spectroscopy. J Biol Phys 2022; 48:253-272. [PMID: 35451661 PMCID: PMC9411374 DOI: 10.1007/s10867-022-09607-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 03/22/2022] [Indexed: 10/18/2022] Open
Abstract
Altered unwinding/bending fluctuations at DNA lesion sites are implicated as plausible mechanisms for damage sensing by DNA-repair proteins. These dynamics are expected to occur on similar timescales as one-dimensional (1D) diffusion of proteins on DNA if effective in stalling these proteins as they scan DNA. We examined the flexibility and dynamics of DNA oligomers containing 3 base pair (bp) mismatched sites specifically recognized in vitro by nucleotide excision repair protein Rad4 (yeast ortholog of mammalian XPC). A previous Forster resonance energy transfer (FRET) study mapped DNA conformational distributions with cytosine analog FRET pair primarily sensitive to DNA twisting/unwinding deformations (Chakraborty et al. Nucleic Acids Res. 46: 1240-1255 (2018)). These studies revealed B-DNA conformations for nonspecific (matched) constructs but significant unwinding for mismatched constructs specifically recognized by Rad4, even in the absence of Rad4. The timescales of these unwinding fluctuations, however, remained elusive. Here, we labeled DNA with Atto550/Atto647N FRET dyes suitable for fluorescence correlation spectroscopy (FCS). With these probes, we detected higher FRET in specific, mismatched DNA compared with matched DNA, reaffirming unwinding/bending deformations in mismatched DNA. FCS unveiled the dynamics of these spontaneous deformations at ~ 300 µs with no fluctuations detected for matched DNA within the ~ 600 ns-10 ms FCS time window. These studies are the first to visualize anomalous unwinding/bending fluctuations in mismatched DNA on timescales that overlap with the < 500 µs "stepping" times of repair proteins on DNA. Such "flexible hinge" dynamics at lesion sites could arrest a diffusing protein to facilitate damage interrogation and recognition.
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Affiliation(s)
- Timour B Ten
- Department of Physics (M/C 273), University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Viktoriya Zvoda
- Department of Physics (M/C 273), University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Manas K Sarangi
- Department of Physics (M/C 273), University of Illinois at Chicago, Chicago, IL, 60607, USA
- Present Address: Department of Physics, Indian Institute of Technology, Patna, 801103, India
| | - Serguei V Kuznetsov
- Department of Physics (M/C 273), University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Anjum Ansari
- Department of Physics (M/C 273), University of Illinois at Chicago, Chicago, IL, 60607, USA.
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8
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Jóźwik IK, Li W, Zhang DW, Wong D, Grawenhoff J, Ballandras-Colas A, Aiyer S, Cherepanov P, Engelman A, Lyumkis D. B-to-A transition in target DNA during retroviral integration. Nucleic Acids Res 2022; 50:8898-8918. [PMID: 35947647 PMCID: PMC9410886 DOI: 10.1093/nar/gkac644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 07/06/2022] [Accepted: 07/19/2022] [Indexed: 01/21/2023] Open
Abstract
Integration into host target DNA (tDNA), a hallmark of retroviral replication, is mediated by the intasome, a multimer of integrase (IN) assembled on viral DNA (vDNA) ends. To ascertain aspects of tDNA recognition during integration, we have solved the 3.5 Å resolution cryo-EM structure of the mouse mammary tumor virus (MMTV) strand transfer complex (STC) intasome. The tDNA adopts an A-like conformation in the region encompassing the sites of vDNA joining, which exposes the sugar-phosphate backbone for IN-mediated strand transfer. Examination of existing retroviral STC structures revealed conservation of A-form tDNA in the analogous regions of these complexes. Furthermore, analyses of sequence preferences in genomic integration sites selectively targeted by six different retroviruses highlighted consistent propensity for A-philic sequences at the sites of vDNA joining. Our structure additionally revealed several novel MMTV IN-DNA interactions, as well as contacts seen in prior STC structures, including conserved Pro125 and Tyr149 residues interacting with tDNA. In infected cells, Pro125 substitutions impacted the global pattern of MMTV integration without significantly altering local base sequence preferences at vDNA insertion sites. Collectively, these data advance our understanding of retroviral intasome structure and function, as well as factors that influence patterns of vDNA integration in genomic DNA.
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Affiliation(s)
- Ilona K Jóźwik
- The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Wen Li
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Center, Boston, MA 02215, USA,Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Da-Wei Zhang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Center, Boston, MA 02215, USA,Department of Medicine, Harvard Medical School, Boston, MA 02115, USA,Institute of Bioinformatics and Medical Engineering, School of Electrical and Information Engineering, Jiangsu University of Technology, Changzhou 213001, China
| | - Doris Wong
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Center, Boston, MA 02215, USA
| | - Julia Grawenhoff
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Center, Boston, MA 02215, USA
| | | | - Sriram Aiyer
- The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Peter Cherepanov
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London NW1 1AT, UK,Department of Infectious Disease, St-Mary's Campus, Imperial College London, London W2 1PG, UK
| | - Alan N Engelman
- Correspondence may also be addressed to Alan N. Engelman. Tel: +1 617 632 4361; Fax: +1 617 632 4338;
| | - Dmitry Lyumkis
- To whom correspondence should be addressed. Tel: +1 858 453 4100 (Ext 1155);
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9
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Park JU, Tsai AWL, Chen TH, Peters JE, Kellogg EH. Mechanistic details of CRISPR-associated transposon recruitment and integration revealed by cryo-EM. Proc Natl Acad Sci U S A 2022; 119:e2202590119. [PMID: 35914146 PMCID: PMC9371665 DOI: 10.1073/pnas.2202590119] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 06/04/2022] [Indexed: 11/18/2022] Open
Abstract
CRISPR-associated transposons (CASTs) are Tn7-like elements that are capable of RNA-guided DNA integration. Although structural data are known for nearly all core transposition components, the transposase component, TnsB, remains uncharacterized. Using cryo-electron microscopy (cryo-EM) structure determination, we reveal the conformation of TnsB during transposon integration for the type V-K CAST system from Scytonema hofmanni (ShCAST). Our structure of TnsB is a tetramer, revealing strong mechanistic relationships with the overall architecture of RNaseH transposases/integrases in general, and in particular the MuA transposase from bacteriophage Mu. However, key structural differences in the C-terminal domains indicate that TnsB's tetrameric architecture is stabilized by a different set of protein-protein interactions compared with MuA. We describe the base-specific interactions along the TnsB binding site, which explain how different CAST elements can function on cognate mobile elements independent of one another. We observe that melting of the 5' nontransferred strand of the transposon end is a structural feature stabilized by TnsB and furthermore is crucial for donor-DNA integration. Although not observed in the TnsB strand-transfer complex, the C-terminal end of TnsB serves a crucial role in transposase recruitment to the target site. The C-terminal end of TnsB adopts a short, structured 15-residue "hook" that decorates TnsC filaments. Unlike full-length TnsB, C-terminal fragments do not appear to stimulate filament disassembly using two different assays, suggesting that additional interactions between TnsB and TnsC are required for redistributing TnsC to appropriate targets. The structural information presented here will help guide future work in modifying these important systems as programmable gene integration tools.
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Affiliation(s)
- Jung-Un Park
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Amy Wei-Lun Tsai
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Tiffany H Chen
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Joseph E Peters
- Department of Microbiology, Cornell University, Ithaca, NY 14853
| | - Elizabeth H Kellogg
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
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10
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Ballandras-Colas A, Chivukula V, Gruszka DT, Shan Z, Singh PK, Pye VE, McLean RK, Bedwell GJ, Li W, Nans A, Cook NJ, Fadel HJ, Poeschla EM, Griffiths DJ, Vargas J, Taylor IA, Lyumkis D, Yardimci H, Engelman AN, Cherepanov P. Multivalent interactions essential for lentiviral integrase function. Nat Commun 2022; 13:2416. [PMID: 35504909 PMCID: PMC9065133 DOI: 10.1038/s41467-022-29928-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 04/07/2022] [Indexed: 12/24/2022] Open
Abstract
A multimer of retroviral integrase (IN) synapses viral DNA ends within a stable intasome nucleoprotein complex for integration into a host cell genome. Reconstitution of the intasome from the maedi-visna virus (MVV), an ovine lentivirus, revealed a large assembly containing sixteen IN subunits1. Herein, we report cryo-EM structures of the lentiviral intasome prior to engagement of target DNA and following strand transfer, refined at 3.4 and 3.5 Å resolution, respectively. The structures elucidate details of the protein-protein and protein-DNA interfaces involved in lentiviral intasome formation. We show that the homomeric interfaces involved in IN hexadecamer formation and the α-helical configuration of the linker connecting the C-terminal and catalytic core domains are critical for MVV IN strand transfer activity in vitro and for virus infectivity. Single-molecule microscopy in conjunction with photobleaching reveals that the MVV intasome can bind a variable number, up to sixteen molecules, of the lentivirus-specific host factor LEDGF/p75. Concordantly, ablation of endogenous LEDGF/p75 results in gross redistribution of MVV integration sites in human and ovine cells. Our data confirm the importance of the expanded architecture observed in cryo-EM studies of lentiviral intasomes and suggest that this organization underlies multivalent interactions with chromatin for integration targeting to active genes.
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Affiliation(s)
- Allison Ballandras-Colas
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
- Institut de Biologie Structurale (IBS) CNRS, CEA, University Grenoble, Grenoble, France
| | - Vidya Chivukula
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, 10016, USA
| | - Dominika T Gruszka
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, London, UK
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics and Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Zelin Shan
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Parmit K Singh
- Department of Cancer Immunology & Virology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Valerie E Pye
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
| | - Rebecca K McLean
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, UK
- The Pirbright Institute, Ash Road, Pirbright, Woking, GU24 0NF, UK
| | - Gregory J Bedwell
- Department of Cancer Immunology & Virology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Wen Li
- Department of Cancer Immunology & Virology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Andrea Nans
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, UK
| | - Nicola J Cook
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK
| | - Hind J Fadel
- Division of Infectious Diseases, Mayo Clinic, Rochester, MN, USA
| | - Eric M Poeschla
- Division of Infectious Diseases, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - David J Griffiths
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, UK
| | - Javier Vargas
- Departmento de Óptica, Universidad Complutense de Madrid, Madrid, Spain
| | - Ian A Taylor
- Macromolecular Structure Laboratory, The Francis Crick Institute, London, UK
| | - Dmitry Lyumkis
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA.
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA.
| | - Hasan Yardimci
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, London, UK.
| | - Alan N Engelman
- Department of Cancer Immunology & Virology, Dana-Farber Cancer Institute, Boston, MA, USA.
- Department of Medicine, Harvard Medical School, Boston, MA, USA.
| | - Peter Cherepanov
- Chromatin Structure and Mobile DNA Laboratory, The Francis Crick Institute, London, UK.
- Department of Infectious Disease, St-Mary's Campus, Imperial College London, London, UK.
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11
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Sklyar T, Kurahina N, Lavrentieva K, Burlaka V, Lykholat T, Lykholat O. Autonomic (Mobile) Genetic Elements of Bacteria and Their Hierarchy. CYTOL GENET+ 2021. [DOI: 10.3103/s0095452721030099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Ochmann MT, Ivics Z. Jumping Ahead with Sleeping Beauty: Mechanistic Insights into Cut-and-Paste Transposition. Viruses 2021; 13:76. [PMID: 33429848 PMCID: PMC7827188 DOI: 10.3390/v13010076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/16/2020] [Accepted: 12/28/2020] [Indexed: 12/13/2022] Open
Abstract
Sleeping Beauty (SB) is a transposon system that has been widely used as a genetic engineering tool. Central to the development of any transposon as a research tool is the ability to integrate a foreign piece of DNA into the cellular genome. Driven by the need for efficient transposon-based gene vector systems, extensive studies have largely elucidated the molecular actors and actions taking place during SB transposition. Close transposon relatives and other recombination enzymes, including retroviral integrases, have served as useful models to infer functional information relevant to SB. Recently obtained structural data on the SB transposase enable a direct insight into the workings of this enzyme. These efforts cumulatively allowed the development of novel variants of SB that offer advanced possibilities for genetic engineering due to their hyperactivity, integration deficiency, or targeting capacity. However, many aspects of the process of transposition remain poorly understood and require further investigation. We anticipate that continued investigations into the structure-function relationships of SB transposition will enable the development of new generations of transposition-based vector systems, thereby facilitating the use of SB in preclinical studies and clinical trials.
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Affiliation(s)
| | - Zoltán Ivics
- Division of Medical Biotechnology, Paul Ehrlich Institute, 63225 Langen, Germany;
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13
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Radukic MT, Brandt D, Haak M, Müller KM, Kalinowski J. Nanopore sequencing of native adeno-associated virus (AAV) single-stranded DNA using a transposase-based rapid protocol. NAR Genom Bioinform 2020; 2:lqaa074. [PMID: 33575623 PMCID: PMC7671332 DOI: 10.1093/nargab/lqaa074] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 08/06/2020] [Accepted: 09/21/2020] [Indexed: 12/14/2022] Open
Abstract
Next-generation sequencing of single-stranded DNA (ssDNA) enables transgene characterization of gene therapy vectors such as adeno-associated virus (AAV), but current library generation uses complicated and potentially biased second-strand synthesis. We report that libraries for nanopore sequencing of ssDNA can be conveniently created without second-strand synthesis using a transposase-based protocol. We show for bacteriophage M13 ssDNA that the MuA transposase has unexpected residual activity on ssDNA, explained in part by transposase action on transient double-stranded hairpins. In case of AAV, library creation is additionally aided by genome hybridization. We demonstrate the power of direct sequencing combined with nanopore long reads by characterizing AAV vector transgenes. Sequencing yielded reads up to full genome length, including GC-rich inverted terminal repeats. Unlike short-read techniques, single reads covered genome-genome and genome-contaminant fusions and other recombination events, whilst additionally providing information on epigenetic methylation. Single-nucleotide variants across the transgene cassette were revealed and secondary genome packaging signals were readily identified. Moreover, comparison of sequence abundance with quantitative polymerase chain reaction results demonstrated the technique's future potential for quantification of DNA impurities in AAV vector stocks. The findings promote direct nanopore sequencing as a fast and versatile platform for ssDNA characterization, such as AAV ssDNA in research and clinical settings.
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Affiliation(s)
- Marco T Radukic
- Faculty of Technology, Bielefeld University, D-33501 Bielefeld, Germany
| | - David Brandt
- Center for Biotechnology (CeBiTec), Bielefeld University, D-33501 Bielefeld, Germany
| | - Markus Haak
- Center for Biotechnology (CeBiTec), Bielefeld University, D-33501 Bielefeld, Germany
| | - Kristian M Müller
- Faculty of Technology, Bielefeld University, D-33501 Bielefeld, Germany
| | - Jörn Kalinowski
- Center for Biotechnology (CeBiTec), Bielefeld University, D-33501 Bielefeld, Germany
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14
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Walker DM, Harshey RM. Deep sequencing reveals new roles for MuB in transposition immunity and target-capture, and redefines the insular Ter region of E. coli. Mob DNA 2020; 11:26. [PMID: 32670425 PMCID: PMC7350765 DOI: 10.1186/s13100-020-00217-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/18/2020] [Indexed: 01/12/2023] Open
Abstract
Background The target capture protein MuB is responsible for the high efficiency of phage Mu transposition within the E. coli genome. However, some targets are off-limits, such as regions immediately outside the Mu ends (cis-immunity) as well as the entire ~ 37 kb genome of Mu (Mu genome immunity). Paradoxically, MuB is responsible for cis-immunity and is also implicated in Mu genome immunity, but via different mechanisms. This study was undertaken to dissect the role of MuB in target choice in vivo. Results We tracked Mu transposition from six different starting locations on the E. coli genome, in the presence and absence of MuB. The data reveal that Mu’s ability to sample the entire genome during a single hop in a clonal population is independent of MuB, and that MuB is responsible for cis-immunity, plays a minor role in Mu genome immunity, and facilitates insertions into transcriptionally active regions. Unexpectedly, transposition patterns in the absence of MuB have helped extend the boundaries of the insular Ter segment of the E. coli genome. Conclusions The results in this study demonstrate unambiguously the operation of two distinct mechanisms of Mu target immunity, only one of which is wholly dependent on MuB. The study also reveals several interesting and hitherto unknown aspects of Mu target choice in vivo, particularly the role of MuB in facilitating the capture of promoter and translation start site targets, likely by displacing macromolecular complexes engaged in gene expression. So also, MuB facilitates transposition into the restricted Ter region of the genome.
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Affiliation(s)
- David M Walker
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712 USA
| | - Rasika M Harshey
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712 USA
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15
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Structure of the P element transpososome reveals new twists on the DD(E/D) theme. Nat Struct Mol Biol 2020; 26:989-990. [PMID: 31659331 DOI: 10.1038/s41594-019-0329-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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16
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Arinkin V, Smyshlyaev G, Barabas O. Jump ahead with a twist: DNA acrobatics drive transposition forward. Curr Opin Struct Biol 2019; 59:168-177. [PMID: 31590109 PMCID: PMC6900584 DOI: 10.1016/j.sbi.2019.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 08/27/2019] [Accepted: 08/29/2019] [Indexed: 11/29/2022]
Abstract
Transposases move discrete pieces of DNA between genomic locations and had a profound impact on evolution. They drove the emergence of important biological functions and are the most frequent proteins encoded in modern genomes. Yet, the molecular principles of their actions have remained largely unclear. Here we review recent structural studies of transposase-DNA complexes and related cellular machineries, which provided unmatched mechanistic insights. We highlight how transposases introduce major DNA twists and kinks at various stages of their reaction and discuss the functional impact of these astounding DNA acrobatics on several aspects of transposition. By comparison with distantly related DNA recombination systems, we propose that forcing DNA into unnatural shapes may be a general strategy to drive rearrangements forward.
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Affiliation(s)
- Vladimir Arinkin
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Georgy Smyshlyaev
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany; European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, UK
| | - Orsolya Barabas
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
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17
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Structure of a P element transposase-DNA complex reveals unusual DNA structures and GTP-DNA contacts. Nat Struct Mol Biol 2019; 26:1013-1022. [PMID: 31659330 DOI: 10.1038/s41594-019-0319-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 09/11/2019] [Indexed: 01/19/2023]
Abstract
P element transposase catalyzes the mobility of P element DNA transposons within the Drosophila genome. P element transposase exhibits several unique properties, including the requirement for a guanosine triphosphate cofactor and the generation of long staggered DNA breaks during transposition. To gain insights into these features, we determined the atomic structure of the Drosophila P element transposase strand transfer complex using cryo-EM. The structure of this post-transposition nucleoprotein complex reveals that the terminal single-stranded transposon DNA adopts unusual A-form and distorted B-form helical geometries that are stabilized by extensive protein-DNA interactions. Additionally, we infer that the bound guanosine triphosphate cofactor interacts with the terminal base of the transposon DNA, apparently to position the P element DNA for catalysis. Our structure provides the first view of the P element transposase superfamily, offers new insights into P element transposition and implies a transposition pathway fundamentally distinct from other cut-and-paste DNA transposases.
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18
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Hickman AB, Voth AR, Ewis H, Li X, Craig NL, Dyda F. Structural insights into the mechanism of double strand break formation by Hermes, a hAT family eukaryotic DNA transposase. Nucleic Acids Res 2019; 46:10286-10301. [PMID: 30239795 PMCID: PMC6212770 DOI: 10.1093/nar/gky838] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/07/2018] [Indexed: 12/12/2022] Open
Abstract
Some DNA transposons relocate from one genomic location to another using a mechanism that involves generating double-strand breaks at their transposon ends by forming hairpins on flanking DNA. The same double-strand break mode is employed by the V(D)J recombinase at signal-end/coding-end junctions during the generation of antibody diversity. How flanking hairpins are formed during DNA transposition has remained elusive. Here, we describe several co-crystal structures of the Hermes transposase bound to DNA that mimics the reaction step immediately prior to hairpin formation. Our results reveal a large DNA conformational change between the initial cleavage step and subsequent hairpin formation that changes which strand is acted upon by a single active site. We observed that two factors affect the conformational change: the complement of divalent metal ions bound by the catalytically essential DDE residues, and the identity of the –2 flanking base pair. Our data also provides a mechanistic link between the efficiency of hairpin formation (an A:T basepair is favored at the –2 position) and Hermes' strong target site preference. Furthermore, we have established that the histidine residue within a conserved C/DxxH motif present in many transposase families interacts directly with the scissile phosphate, suggesting a crucial role in catalysis.
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Affiliation(s)
- Alison B Hickman
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrea Regier Voth
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hosam Ewis
- Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Xianghong Li
- Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Nancy L Craig
- Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Fred Dyda
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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19
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Rasila TS, Pulkkinen E, Kiljunen S, Haapa-Paananen S, Pajunen MI, Salminen A, Paulin L, Vihinen M, Rice PA, Savilahti H. Mu transpososome activity-profiling yields hyperactive MuA variants for highly efficient genetic and genome engineering. Nucleic Acids Res 2019; 46:4649-4661. [PMID: 29294068 PMCID: PMC5961161 DOI: 10.1093/nar/gkx1281] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 12/21/2017] [Indexed: 11/22/2022] Open
Abstract
The phage Mu DNA transposition system provides a versatile species non-specific tool for molecular biology, genetic engineering and genome modification applications. Mu transposition is catalyzed by MuA transposase, with DNA cleavage and integration reactions ultimately attaching the transposon DNA to target DNA. To improve the activity of the Mu DNA transposition machinery, we mutagenized MuA protein and screened for hyperactivity-causing substitutions using an in vivo assay. The individual activity-enhancing substitutions were mapped onto the MuA–DNA complex structure, containing a tetramer of MuA transposase, two Mu end segments and a target DNA. This analysis, combined with the varying effect of the mutations in different assays, implied that the mutations exert their effects in several ways, including optimizing protein–protein and protein–DNA contacts. Based on these insights, we engineered highly hyperactive versions of MuA, by combining several synergistically acting substitutions located in different subdomains of the protein. Purified hyperactive MuA variants are now ready for use as second-generation tools in a variety of Mu-based DNA transposition applications. These variants will also widen the scope of Mu-based gene transfer technologies toward medical applications such as human gene therapy. Moreover, the work provides a platform for further design of custom transposases.
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Affiliation(s)
- Tiina S Rasila
- Division of Genetics and Physiology, Department of Biology, FI-20014 University of Turku, Turku, Finland.,Institute of Biotechnology, Viikki Biocenter, P. O. Box 56, FI-00014 University of Helsinki, Helsinki, Finland
| | - Elsi Pulkkinen
- Division of Genetics and Physiology, Department of Biology, FI-20014 University of Turku, Turku, Finland
| | - Saija Kiljunen
- Division of Genetics and Physiology, Department of Biology, FI-20014 University of Turku, Turku, Finland
| | - Saija Haapa-Paananen
- Division of Genetics and Physiology, Department of Biology, FI-20014 University of Turku, Turku, Finland
| | - Maria I Pajunen
- Division of Biochemistry and Biotechnology, Department of Biosciences, FI-00014 University of Helsinki, Helsinki, Finland
| | - Anu Salminen
- Department of Biochemistry, FI-20014 University of Turku, Turku, Finland
| | - Lars Paulin
- Institute of Biotechnology, Viikki Biocenter, P. O. Box 56, FI-00014 University of Helsinki, Helsinki, Finland
| | - Mauno Vihinen
- Department of Experimental Medical Science, Lund University, SE-221 84, Lund, Sweden
| | - Phoebe A Rice
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Harri Savilahti
- Division of Genetics and Physiology, Department of Biology, FI-20014 University of Turku, Turku, Finland.,Institute of Biotechnology, Viikki Biocenter, P. O. Box 56, FI-00014 University of Helsinki, Helsinki, Finland
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20
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Toussaint A, Rice PA. Transposable phages, DNA reorganization and transfer. Curr Opin Microbiol 2017; 38:88-94. [PMID: 28551392 DOI: 10.1016/j.mib.2017.04.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/13/2017] [Accepted: 04/19/2017] [Indexed: 02/07/2023]
Abstract
Transposable bacteriophages have long been known to necessarily and randomly integrate their DNA in their host genome, where they amplify by successive rounds of replicative transposition, profoundly reorganizing that genome. As a result of such transposition, a conjugative element (plasmid or genomic island), can either become integrated in the chromosome or receive chromosome segments, which can then be transferred to new hosts by conjugation. In recent years, more and more transposable phages have been isolated or detected by sequence similarity searches in a wide range of bacteria, supporting the idea that this mode of HGT may be pervasive in natural bacterial populations.
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Affiliation(s)
- Ariane Toussaint
- Génétique et Physiologie Bactérienne, Université Libre de Bruxelles, IBMM-DBM, 12 Rue des Professeurs Jeneer et Brachet, B 6041 Gosselies, Belgium.
| | - Phoebe A Rice
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 E. 57th St., Chicago, IL 60637, USA
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