1
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Ouyang Y, Dong J, Willner I. Dynamic DNA Networks-Guided Directional and Orthogonal Transient Biocatalytic Cascades. J Am Chem Soc 2023; 145:22135-22149. [PMID: 37773962 PMCID: PMC10571085 DOI: 10.1021/jacs.3c08020] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Indexed: 10/01/2023]
Abstract
DNA frameworks, consisting of constitutional dynamic networks (CDNs) undergoing fuel-driven reconfiguration, are coupled to a dissipative reaction module that triggers the reconfigured CDNs into a transient intermediate CDNs recovering the parent CDN state. Biocatalytic cascades consisting of the glucose oxidase (GOx)/horseradish peroxidase (HRP) couple or the lactate dehydrogenase (LDH)/nicotinamide adenine dinucleotide (NAD+) couple are tethered to the constituents of two different CDNs, allowing the CDNs-guided operation of the spatially confined GOx/HRP or LDH/NAD+ biocatalytic cascades. By applying two different fuel triggers, the directional transient CDN-guided upregulation/downregulation of the two biocatalytic cascades are demonstrated. By mixing the GOx/HRP-biocatalyst-modified CDN with the LDH/NAD+-biocatalyst-functionalized CDN, a composite CDN is assembled. Triggering the composite CDN with two different fuel strands results in orthogonal transient upregulation of the GOx/HRP cascade and transient downregulation of the LDH/NAD+ cascade or vice versa. The transient CDNs-guided biocatalytic cascades are computationally simulated by kinetic models, and the computational analyses allow the prediction of the performance of transient biocatalytic cascades under different auxiliary conditions. The concept of orthogonally triggered temporal, transient, biocatalytic cascades by means of CDN frameworks is applied to design an orthogonally operating CDN for the temporal upregulated or downregulated transient thrombin-induced coagulation of fibrinogen to fibrin.
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Affiliation(s)
- Yu Ouyang
- The Institute of Chemistry,
Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Jiantong Dong
- The Institute of Chemistry,
Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Itamar Willner
- The Institute of Chemistry,
Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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2
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Blair K, Tehseen M, Raducanu VS, Shahid T, Lancey C, Rashid F, Crehuet R, Hamdan SM, De Biasio A. Mechanism of human Lig1 regulation by PCNA in Okazaki fragment sealing. Nat Commun 2022; 13:7833. [PMID: 36539424 PMCID: PMC9767926 DOI: 10.1038/s41467-022-35475-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
During lagging strand synthesis, DNA Ligase 1 (Lig1) cooperates with the sliding clamp PCNA to seal the nicks between Okazaki fragments generated by Pol δ and Flap endonuclease 1 (FEN1). We present several cryo-EM structures combined with functional assays, showing that human Lig1 recruits PCNA to nicked DNA using two PCNA-interacting motifs (PIPs) located at its disordered N-terminus (PIPN-term) and DNA binding domain (PIPDBD). Once Lig1 and PCNA assemble as two-stack rings encircling DNA, PIPN-term is released from PCNA and only PIPDBD is required for ligation to facilitate the substrate handoff from FEN1. Consistently, we observed that PCNA forms a defined complex with FEN1 and nicked DNA, and it recruits Lig1 to an unoccupied monomer creating a toolbelt that drives the transfer of DNA to Lig1. Collectively, our results provide a structural model on how PCNA regulates FEN1 and Lig1 during Okazaki fragments maturation.
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Affiliation(s)
- Kerry Blair
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell Biology, University of Leicester, Lancaster Rd, Leicester, LE1 7HB, UK
| | - Muhammad Tehseen
- Bioscience Program, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia
| | - Vlad-Stefan Raducanu
- Bioscience Program, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia
| | - Taha Shahid
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell Biology, University of Leicester, Lancaster Rd, Leicester, LE1 7HB, UK
- Bioscience Program, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia
| | - Claudia Lancey
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell Biology, University of Leicester, Lancaster Rd, Leicester, LE1 7HB, UK
| | - Fahad Rashid
- Bioscience Program, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia
| | - Ramon Crehuet
- CSIC-Institute for Advanced Chemistry of Catalonia (IQAC) C/ Jordi Girona 18-26, 08034, Barcelona, Spain
| | - Samir M Hamdan
- Bioscience Program, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia.
| | - Alfredo De Biasio
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell Biology, University of Leicester, Lancaster Rd, Leicester, LE1 7HB, UK.
- Bioscience Program, Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia.
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3
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Rajendran A, Krishnamurthy K, Giridasappa A, Nakata E, Morii T. Stabilization and structural changes of 2D DNA origami by enzymatic ligation. Nucleic Acids Res 2021; 49:7884-7900. [PMID: 34289063 PMCID: PMC8373134 DOI: 10.1093/nar/gkab611] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 06/16/2021] [Accepted: 07/06/2021] [Indexed: 12/15/2022] Open
Abstract
The low thermal stability of DNA nanostructures is the major drawback in their practical applications. Most of the DNA nanotubes/tiles and the DNA origami structures melt below 60°C due to the presence of discontinuities in the phosphate backbone (i.e., nicks) of the staple strands. In molecular biology, enzymatic ligation is commonly used to seal the nicks in the duplex DNA. However, in DNA nanotechnology, the ligation procedures are neither optimized for the DNA origami nor routinely applied to link the nicks in it. Here, we report a detailed analysis and optimization of the conditions for the enzymatic ligation of the staple strands in four types of 2D square lattice DNA origami. Our results indicated that the ligation takes overnight, efficient at 37°C rather than the usual 16°C or room temperature, and typically requires much higher concentration of T4 DNA ligase. Under the optimized conditions, up to 10 staples ligation with a maximum ligation efficiency of 55% was achieved. Also, the ligation is found to increase the thermal stability of the origami as low as 5°C to as high as 20°C, depending on the structure. Further, our studies indicated that the ligation of the staple strands influences the globular structure/planarity of the DNA origami, and the origami is more compact when the staples are ligated. The globular structure of the native and ligated origami was also found to be altered dynamically and progressively upon ethidium bromide intercalation in a concentration-dependent manner.
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Affiliation(s)
| | | | - Amulya Giridasappa
- Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Eiji Nakata
- Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Takashi Morii
- Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
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4
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Çağlayan M. Interplay between DNA Polymerases and DNA Ligases: Influence on Substrate Channeling and the Fidelity of DNA Ligation. J Mol Biol 2019; 431:2068-2081. [PMID: 31034893 DOI: 10.1016/j.jmb.2019.04.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 04/18/2019] [Accepted: 04/18/2019] [Indexed: 02/06/2023]
Abstract
DNA ligases are a highly conserved group of nucleic acid enzymes that play an essential role in DNA repair, replication, and recombination. This review focuses on functional interaction between DNA polymerases and DNA ligases in the repair of single- and double-strand DNA breaks, and discusses the notion that the substrate channeling during DNA polymerase-mediated nucleotide insertion coupled to DNA ligation could be a mechanism to minimize the release of potentially mutagenic repair intermediates. Evidence suggesting that DNA ligases are essential for cell viability includes the fact that defects or insufficiency in DNA ligase are casually linked to genome instability. In the future, it may be possible to develop small molecule inhibitors of mammalian DNA ligases and/or their functional protein partners that potentiate the effects of chemotherapeutic compounds and improve cancer treatment outcomes.
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Affiliation(s)
- Melike Çağlayan
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA.
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5
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Milton ME, Nelson SW. Replication and maintenance of the Plasmodium falciparum apicoplast genome. Mol Biochem Parasitol 2016; 208:56-64. [PMID: 27338018 DOI: 10.1016/j.molbiopara.2016.06.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 06/14/2016] [Accepted: 06/19/2016] [Indexed: 12/18/2022]
Abstract
Members of the phylum Apicomplexa are responsible for many devastating diseases including malaria (Plasmodium spp.), toxoplasmosis (Toxoplasma gondii), babesiosis (Babesia bovis), and cyclosporiasis (Cyclospora cayetanensis). Most Apicomplexans contain a unique and essential organelle called the apicoplast. Derived from an ancient chloroplast, the apicoplast replicates and maintains a 35 kilobase (kb) circular genome. Due to its essential nature within the parasite, drugs targeted to proteins involved in DNA replication and repair of the apicoplast should be potent and specific. This review summarizes the current knowledge surrounding the replication and repair of the Plasmodium falciparum apicoplast genome and identifies several putative proteins involved in replication and repair pathways.
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Affiliation(s)
- Morgan E Milton
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames IA 50011, USA
| | - Scott W Nelson
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames IA 50011, USA.
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6
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Abstract
The base sequence in nucleic acids encodes substantial structural and functional information into the biopolymer. This encoded information provides the basis for the tailoring and assembly of DNA machines. A DNA machine is defined as a molecular device that exhibits the following fundamental features. (1) It performs a fuel-driven mechanical process that mimics macroscopic machines. (2) The mechanical process requires an energy input, "fuel." (3) The mechanical operation is accompanied by an energy consumption process that leads to "waste products." (4) The cyclic operation of the DNA devices, involves the use of "fuel" and "anti-fuel" ingredients. A variety of DNA-based machines are described, including the construction of "tweezers," "walkers," "robots," "cranes," "transporters," "springs," "gears," and interlocked cyclic DNA structures acting as reconfigurable catenanes, rotaxanes, and rotors. Different "fuels", such as nucleic acid strands, pH (H⁺/OH⁻), metal ions, and light, are used to trigger the mechanical functions of the DNA devices. The operation of the devices in solution and on surfaces is described, and a variety of optical, electrical, and photoelectrochemical methods to follow the operations of the DNA machines are presented. We further address the possible applications of DNA machines and the future perspectives of molecular DNA devices. These include the application of DNA machines as functional structures for the construction of logic gates and computing, for the programmed organization of metallic nanoparticle structures and the control of plasmonic properties, and for controlling chemical transformations by DNA machines. We further discuss the future applications of DNA machines for intracellular sensing, controlling intracellular metabolic pathways, and the use of the functional nanostructures for drug delivery and medical applications.
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7
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Wang F, Lu CH, Willner I. From cascaded catalytic nucleic acids to enzyme-DNA nanostructures: controlling reactivity, sensing, logic operations, and assembly of complex structures. Chem Rev 2014; 114:2881-941. [PMID: 24576227 DOI: 10.1021/cr400354z] [Citation(s) in RCA: 493] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Fuan Wang
- Institute of Chemistry, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
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8
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Van Cor-Hosmer SK, Kim DH, Daly MB, Daddacha W, Kim B. Restricted 5'-end gap repair of HIV-1 integration due to limited cellular dNTP concentrations in human primary macrophages. J Biol Chem 2013; 288:33253-62. [PMID: 24097986 DOI: 10.1074/jbc.m113.486787] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
HIV-1 proviral DNA integration into host chromosomal DNA is only partially completed by the viral integrase, leaving two single-stranded DNA gaps with 5'-end mismatched viral DNA flaps. It has been inferred that these gaps are repaired by the cellular DNA repair machinery. Here, we investigated the efficiency of gap repair at integration sites in different HIV-1 target cell types. First, we found that the general gap repair machinery in macrophages was attenuated compared with that in dividing CD4(+) T cells. In fact, the repair in macrophages was heavily reliant upon host DNA polymerase β (Pol β). Second, we tested whether the poor dNTP availability found in macrophages is responsible for the delayed HIV-1 proviral DNA integration in this cell type because the Km value of Pol β is much higher than the dNTP concentrations found in macrophages. Indeed, with the use of a modified quantitative AluI PCR assay, we demonstrated that the elevation of cellular dNTP concentrations accelerated DNA gap repair in macrophages at HIV-1 proviral DNA integration sites. Finally, we found that human monocytes, which are resistant to HIV-1 infection, exhibited severely restricted gap repair capacity due not only to the very low levels of dNTPs detected but also to the significantly reduced expression of Pol β. Taken together, these results suggest that the low dNTP concentrations found in macrophages and monocytes can restrict the repair steps necessary for HIV-1 integration.
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Affiliation(s)
- Sarah K Van Cor-Hosmer
- From the Department of Microbiology and Immunology, University of Rochester, Rochester, New York 14627
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9
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Al-Manasra AM, Al-Razem F. Cloning and expression of a new bacteriophage (SHPh) DNA ligase isolated from sewage. J Genet Eng Biotechnol 2012. [DOI: 10.1016/j.jgeb.2012.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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10
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Bichara M, Meier M, Wagner J, Cordonnier A, Lambert IB. Postreplication repair mechanisms in the presence of DNA adducts in Escherichia coli. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2011; 727:104-22. [DOI: 10.1016/j.mrrev.2011.04.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 04/25/2011] [Accepted: 04/26/2011] [Indexed: 02/02/2023]
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11
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Ferrer M, Golyshina OV, Beloqui A, Böttger LH, Andreu JM, Polaina J, De Lacey AL, Trautwein AX, Timmis KN, Golyshin PN. A purple acidophilic di-ferric DNA ligase from Ferroplasma. Proc Natl Acad Sci U S A 2008; 105:8878-83. [PMID: 18577594 PMCID: PMC2438275 DOI: 10.1073/pnas.0800071105] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Indexed: 11/18/2022] Open
Abstract
We describe here an extraordinary purple-colored DNA ligase, LigFa, from the acidophilic ferrous iron-oxidizing archaeon Ferroplasma acidiphilum, a di-ferric enzyme with an extremely low pH activity optimum. Unlike any other DNA ligase studied to date, LigFa contains two Fe(3+)-tyrosinate centers and lacks any requirement for either Mg(2+) or K(+) for activity. DNA ligases from closest phylogenetic and ecophysiological relatives have normal pH optima (6.0-7.5), lack iron, and require Mg(2+)/K(+) for activity. Ferric iron retention is pH-dependent, with release resulting in partial protein unfolding and loss of activity. Reduction of the Fe(3+) to Fe(2+) results in an 80% decrease in DNA substrate binding and an increase in the pH activity optimum to 5.0. DNA binding induces significant conformational change around the iron site(s), suggesting that the ferric irons of LigFa act both as structure organizing and stabilizing elements and as Lewis acids facilitating DNA binding at low pH.
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Affiliation(s)
- Manuel Ferrer
- *Consejo Superior de Investigaciones Científicas, Institute of Catalysis, 28049 Madrid, Spain
| | - Olga V. Golyshina
- Environmental Microbiology Laboratory, Helmholtz Centre for Infection Research (HZI), 38124 Braunschweig, Germany
| | - Ana Beloqui
- *Consejo Superior de Investigaciones Científicas, Institute of Catalysis, 28049 Madrid, Spain
| | - Lars H. Böttger
- Institute of Physics, University of Lübeck, 23538 Lübeck, Germany
| | - José M. Andreu
- Consejo Superior de Investigaciones Científicas, Centro de Investigaciones Biológicas, 28040 Madrid, Spain
| | - Julio Polaina
- Consejo Superior de Investigaciones Científicas, Instituto de Agroquímica y Tecnología de Alimentos, 46980 Valencia, Spain
| | - Antonio L. De Lacey
- *Consejo Superior de Investigaciones Científicas, Institute of Catalysis, 28049 Madrid, Spain
| | | | - Kenneth N. Timmis
- Environmental Microbiology Laboratory, Helmholtz Centre for Infection Research (HZI), 38124 Braunschweig, Germany
- **Institute of Microbiology, Carolo-Wilhelmina Technical University of Braunschweig, 38106 Braunschweig, Germany
| | - Peter N. Golyshin
- Environmental Microbiology Laboratory, Helmholtz Centre for Infection Research (HZI), 38124 Braunschweig, Germany
- **Institute of Microbiology, Carolo-Wilhelmina Technical University of Braunschweig, 38106 Braunschweig, Germany
- School of Biological Sciences, Bangor University, Gwynedd, LL57 2UW, United Kingdom; and
- Centre for Integrated Research in the Rural Environment, Aberystwyth University–Bangor University Partnership (CIRRE), Aberystwyth, Ceredigion SY23 2AX, United Kingdom
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12
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Buguliskis JS, Casta LJ, Butz CE, Matsumoto Y, Taraschi TF. Expression and biochemical characterization of Plasmodium falciparum DNA ligase I. Mol Biochem Parasitol 2007; 155:128-37. [PMID: 17688957 PMCID: PMC2692355 DOI: 10.1016/j.molbiopara.2007.06.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Revised: 06/21/2007] [Accepted: 06/22/2007] [Indexed: 11/18/2022]
Abstract
We report that Plasmodium falciparum (Pf) encodes a 912 amino acid ATP-dependent DNA ligase. Protein sequence analysis of Pf DNA ligase I indicates a strong sequence similarity, particularly in the C-terminal region, to DNA ligase I homologues. The activity of recombinant Pf DNA ligase I (PfLigI) was investigated using protein expressed in HEK293 cells. The PfLigI gene product is approximately 94kDa and catalyzes phosphodiester bond formation on a singly nicked DNA substrate. The enzyme is most active at alkaline pH (8.5) and with Mg(2+) or Mn(2+) and ATP as cofactors. Kinetic studies of PfLigI revealed that the enzyme has similar substrate affinity (K(m) 2.6nM) as compared to human DNA ligase I and k(cat) (2.3x10(-3)s(-1)) and k(cat)/K(m) (8.8x10(5)M(-1)s(-1)) which are similar to other ATP-dependent DNA ligases. PfLigI was able to join RNA-DNA substrates only when the RNA sequence was upstream of the nick, confirming that it is DNA ligase I and has no associated DNA ligase III like activity.
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Affiliation(s)
- Jeffrey S. Buguliskis
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Louis J. Casta
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Charles E. Butz
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Yoshihiro Matsumoto
- Medical Science Division, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, Pennsylvania 19111
| | - Theodore F. Taraschi
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
- Address Correspondence: Theodore F. Taraschi, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, Pennsylvania, 19107-6731, Tel. 215-503-5020 Fax. 215-503-0206 E-mail:
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13
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O'Neill P, Rothemund PWK, Kumar A, Fygenson DK. Sturdier DNA nanotubes via ligation. NANO LETTERS 2006; 6:1379-83. [PMID: 16834415 DOI: 10.1021/nl0603505] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
DNA nanotubes are crystalline self-assemblies of DNA tiles approximately 10 nm in diameter that readily grow tens of micrometers in length. Easy assembly, programmability, and stiffness make them interesting for many applications, but DNA nanotubes begin to melt at temperatures below 40 degrees C, break open when deposited on mica or scanned by AFM, and disintegrate in deionized water. These weaknesses can be traced to the presence of discontinuities in the phosphate backbone, called nicks. The nanotubes studied here have five nicks, one in the core of a tile and one at each corner. We report the successful ligation of all four corner nicks by T4 DNA ligase. Although ligation does not change the nanotubes' stiffness, ligated nanotubes withstand temperatures over 70 degrees C, resist breaking during AFM, and are stable in pure water for over a month. Ligated DNA nanotubes are thus physically and chemically sturdy enough to withstand the manipulations necessary for many technological applications.
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Affiliation(s)
- Patrick O'Neill
- Department of Physics, University of California, Santa Barbara, 93106, USA
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14
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Indiani C, McInerney P, Georgescu R, Goodman MF, O'Donnell M. A Sliding-Clamp Toolbelt Binds High- and Low-Fidelity DNA Polymerases Simultaneously. Mol Cell 2005; 19:805-15. [PMID: 16168375 DOI: 10.1016/j.molcel.2005.08.011] [Citation(s) in RCA: 165] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2005] [Revised: 07/13/2005] [Accepted: 08/11/2005] [Indexed: 12/01/2022]
Abstract
This report demonstrates that the beta sliding clamp of E. coli binds two different DNA polymerases at the same time. One is the high-fidelity Pol III chromosomal replicase and the other is Pol IV, a low-fidelity lesion bypass Y family polymerase. Further, polymerase switching on the primed template junction is regulated in a fashion that limits the action of the low-fidelity Pol IV. Under conditions that cause Pol III to stall on DNA, Pol IV takes control of the primed template. After the stall is relieved, Pol III rapidly regains control of the primed template junction from Pol IV and retains it while it is moving, becoming resistant to further Pol IV takeover events. These polymerase dynamics within the beta toolbelt complex restrict the action of the error-prone Pol IV to only the area on DNA where it is required.
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Affiliation(s)
- Chiara Indiani
- Laboratory of DNA Replication, The Rockefeller University, 1230 York Avenue, New York, New York 10021, USA
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