1
|
Xu L, Halma MTJ, Wuite GJL. Mapping fast DNA polymerase exchange during replication. Nat Commun 2024; 15:5328. [PMID: 38909023 PMCID: PMC11193749 DOI: 10.1038/s41467-024-49612-3] [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: 10/30/2023] [Accepted: 06/11/2024] [Indexed: 06/24/2024] Open
Abstract
Despite extensive studies on DNA replication, the exchange mechanisms of DNA polymerase during replication remain unclear. Existing models propose that this exchange is facilitated by protein partners like helicase. Here we present data, employing a combination of mechanical DNA manipulation and single fluorescent protein observation, that reveal DNA polymerase undergoing rapid and autonomous exchange during replication not coordinated by other proteins. The DNA polymerase shows fast unbinding and rebinding dynamics, displaying a preference for either exonuclease or polymerase activity, or pausing events, during each brief binding event. We also observed a 'memory effect' in DNA polymerase rebinding, i.e., the enzyme tends to preserve its prior activity upon reassociation. This effect, potentially linked to the ssDNA/dsDNA junction's conformation, might play a role in regulating binding preference enabling high processivity amidst rapid protein exchange. Taken together, our findings support an autonomous replication model that includes rapid protein exchange, burst of activity, and a 'memory effect' while moving processively forward.
Collapse
Affiliation(s)
- Longfu Xu
- Department of Physics and Astronomy and LaserLab, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Matthew T J Halma
- Department of Physics and Astronomy and LaserLab, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Gijs J L Wuite
- Department of Physics and Astronomy and LaserLab, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
| |
Collapse
|
2
|
Guo L, Bao Y, Zhao Y, Ren Z, Bi L, Zhang X, Liu C, Hou X, Wang MD, Sun B. Joint Efforts of Replicative Helicase and SSB Ensure Inherent Replicative Tolerance of G-Quadruplex. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2307696. [PMID: 38126671 PMCID: PMC10916570 DOI: 10.1002/advs.202307696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/28/2023] [Indexed: 12/23/2023]
Abstract
G-quadruplex (G4) is a four-stranded noncanonical DNA structure that has long been recognized as a potential hindrance to DNA replication. However, how replisomes effectively deal with G4s to avoid replication failure is still obscure. Here, using single-molecule and ensemble approaches, the consequence of the collision between bacteriophage T7 replisome and an intramolecular G4 located on either the leading or lagging strand is examined. It is found that the adjacent fork junctions induced by G4 formation incur the binding of T7 DNA polymerase (DNAP). In addition to G4, these inactive DNAPs present insuperable obstacles, impeding the progression of DNA synthesis. Nevertheless, T7 helicase can dismantle them and resolve lagging-strand G4s, paving the way for the advancement of the replication fork. Moreover, with the assistance of the single-stranded DNA binding protein (SSB) gp2.5, T7 helicase is also capable of maintaining a leading-strand G4 structure in an unfolded state, allowing for a fraction of T7 DNAPs to synthesize through without collapse. These findings broaden the functional repertoire of a replicative helicase and underscore the inherent G4 tolerance of a replisome.
Collapse
Affiliation(s)
- Lijuan Guo
- School of Life Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Yanling Bao
- School of Life Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Yilin Zhao
- School of Life Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Zhiyun Ren
- School of Life Science and TechnologyShanghaiTech UniversityShanghai201210China
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesShanghai200031China
- University of Chinese Academy of SciencesBeijing100049China
| | - Lulu Bi
- School of Life Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Xia Zhang
- School of Life Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai201210China
| | - Xi‐Miao Hou
- College of Life SciencesNorthwest A&F UniversityYanglingShaanxi712100China
| | - Michelle D. Wang
- Department of Physics, Laboratory of Atomic and Solid State PhysicsCornell UniversityIthacaNY14853USA
- Howard Hughes Medical InstituteCornell UniversityIthacaNY14853USA
| | - Bo Sun
- School of Life Science and TechnologyShanghaiTech UniversityShanghai201210China
| |
Collapse
|
3
|
Dulin D. An Introduction to Magnetic Tweezers. Methods Mol Biol 2024; 2694:375-401. [PMID: 37824014 DOI: 10.1007/978-1-0716-3377-9_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Magnetic tweezers are a single-molecule force and torque spectroscopy technique that enable the mechanical interrogation in vitro of biomolecules, such as nucleic acids and proteins. They use a magnetic field originating from either permanent magnets or electromagnets to attract a magnetic particle, thus stretching the tethering biomolecule. They nicely complement other force spectroscopy techniques such as optical tweezers and atomic force microscopy (AFM) as they operate as a very stable force clamp, enabling long-duration experiments over a very broad range of forces spanning from 10 fN to 1 nN, with 1-10 milliseconds time and sub-nanometer spatial resolution. Their simplicity, robustness, and versatility have made magnetic tweezers a key technique within the field of single-molecule biophysics, being broadly applied to study the mechanical properties of, e.g., nucleic acids, genome processing molecular motors, protein folding, and nucleoprotein filaments. Furthermore, magnetic tweezers allow for high-throughput single-molecule measurements by tracking hundreds of biomolecules simultaneously both in real-time and at high spatiotemporal resolution. Magnetic tweezers naturally combine with surface-based fluorescence spectroscopy techniques, such as total internal reflection fluorescence microscopy, enabling correlative fluorescence and force/torque spectroscopy on biomolecules. This chapter presents an introduction to magnetic tweezers including a description of the hardware, the theory behind force calibration, its spatiotemporal resolution, combining it with other techniques, and a (non-exhaustive) overview of biological applications.
Collapse
Affiliation(s)
- David Dulin
- LaserLaB Amsterdam and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.
| |
Collapse
|
4
|
Bai J, Zou J, Cao Y, Du Y, Chen T. Recognition of an Unnatural Base Pair by Tool Enzymes from Bacteriophages and Its Application in the Enzymatic Preparation of DNA with an Expanded Genetic Alphabet. ACS Synth Biol 2023; 12:2676-2690. [PMID: 37590442 DOI: 10.1021/acssynbio.3c00250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
Unnatural base pairs (UBPs) have been developed to expand the genetic alphabet in vitro and in vivo. UBP dNaM-dTPT3 and its analogues have been successfully used to construct the first set of semi-synthetic organisms, which suggested the great potential of UBPs to be used for producing novel synthetic biological parts. Two prerequisites for doing so are the facile manipulation of DNA containing UBPs with common tool enzymes, including DNA polymerases and ligases, and the easy availability of UBP-containing DNA strands. Besides, for the application of UBPs in phage synthetic biology, the recognition of UBPs by phage enzymes is essential. Here, we first explore the recognition of dNaM-dTPT3 by a family B DNA polymerase from bacteriophage, T4 DNA polymerase D219A. Results from primer extension, steady-state kinetics, and gap-filling experiments suggest that T4 DNA polymerase D219A can efficiently and faithfully replicate dNaM-dTPT3, and efficiently fill a gap by inserting dTPT3TP or its analogues opposite dNaM. We then systematically explore the recognition of dNaM-dTPT3 and its analogues by different DNA ligases from bacteriophages and find that these DNA ligases are generally able to efficiently ligate the DNA nick next to dNaM-dTPT3 or its analogues, albeit with slightly different efficiencies. These results suggest more enzymatic tools for the manipulation of dNaM-dTPT3 and indicate the potential use of dNaM-dTPT3 for expanding the genetic alphabet in bacteriophages. Based on these results, we next develop and comprehensively optimize an upgraded method for enzymatic preparation of unnatural nucleobase (UB)-containing DNA oligonucleotides with good simplicity and universality.
Collapse
Affiliation(s)
- Jingsi Bai
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - Jinrong Zou
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - Yijun Cao
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - Yuhui Du
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - Tingjian Chen
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
| |
Collapse
|
5
|
Oscorbin I, Filipenko M. Bst polymerase - a humble relative of Taq polymerase. Comput Struct Biotechnol J 2023; 21:4519-4535. [PMID: 37767105 PMCID: PMC10520511 DOI: 10.1016/j.csbj.2023.09.008] [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: 05/14/2023] [Revised: 08/31/2023] [Accepted: 09/10/2023] [Indexed: 09/29/2023] Open
Abstract
DNA polymerases are a superfamily of enzymes synthesizing DNA using DNA as a template. They are essential for nucleic acid metabolism and for DNA replication and repair. Modern biotechnology and molecular diagnostics rely heavily on DNA polymerases in analyzing nucleic acids. Among a variety of discovered DNA polymerases, Bst polymerase, a large fragment of DNA polymerase I from Geobacillus stearothermophilus, is one of the most commonly used but is not as well studied as Taq polymerase. The ability of Bst polymerase to displace an upstream DNA strand during synthesis, coupled with its moderate thermal stability, has provided the basis for several isothermal DNA amplification methods, including LAMP, WGA, RCA, and many others. Bst polymerase is one of the key components defining the robustness and analytical characteristics of diagnostic test systems based on isothermal amplification. Here, we present an overview of the biochemical and structural features of Bst polymerase and provide information on its mutated analogs.
Collapse
Affiliation(s)
- Igor Oscorbin
- Laboratory of Pharmacogenomics, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences (ICBFM SB RAS), 8 Lavrentiev Avenue, Novosibirsk 630090, Russia
| | - Maxim Filipenko
- Laboratory of Pharmacogenomics, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences (ICBFM SB RAS), 8 Lavrentiev Avenue, Novosibirsk 630090, Russia
| |
Collapse
|
6
|
Ordóñez CD, Redrejo-Rodríguez M. DNA Polymerases for Whole Genome Amplification: Considerations and Future Directions. Int J Mol Sci 2023; 24:ijms24119331. [PMID: 37298280 DOI: 10.3390/ijms24119331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 06/12/2023] Open
Abstract
In the same way that specialized DNA polymerases (DNAPs) replicate cellular and viral genomes, only a handful of dedicated proteins from various natural origins as well as engineered versions are appropriate for competent exponential amplification of whole genomes and metagenomes (WGA). Different applications have led to the development of diverse protocols, based on various DNAPs. Isothermal WGA is currently widely used due to the high performance of Φ29 DNA polymerase, but PCR-based methods are also available and can provide competent amplification of certain samples. Replication fidelity and processivity must be considered when selecting a suitable enzyme for WGA. However, other properties, such as thermostability, capacity to couple replication, and double helix unwinding, or the ability to maintain DNA replication opposite to damaged bases, are also very relevant for some applications. In this review, we provide an overview of the different properties of DNAPs widely used in WGA and discuss their limitations and future research directions.
Collapse
Affiliation(s)
- Carlos D Ordóñez
- CIC bioGUNE, Bizkaia Science and Technology Park, Building 800, 48160 Derio, Spain
| | - Modesto Redrejo-Rodríguez
- Department of Biochemistry, Universidad Autónoma de Madrid and Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, 28029 Madrid, Spain
| |
Collapse
|
7
|
Plaza-G A I, Lemishko KM, Crespo R, Truong TQ, Kaguni LS, Cao-García FJ, Ciesielski GL, Ibarra B. Mechanism of strand displacement DNA synthesis by the coordinated activities of human mitochondrial DNA polymerase and SSB. Nucleic Acids Res 2023; 51:1750-1765. [PMID: 36744436 PMCID: PMC9976888 DOI: 10.1093/nar/gkad037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 12/16/2022] [Accepted: 01/12/2023] [Indexed: 02/07/2023] Open
Abstract
Many replicative DNA polymerases couple DNA replication and unwinding activities to perform strand displacement DNA synthesis, a critical ability for DNA metabolism. Strand displacement is tightly regulated by partner proteins, such as single-stranded DNA (ssDNA) binding proteins (SSBs) by a poorly understood mechanism. Here, we use single-molecule optical tweezers and biochemical assays to elucidate the molecular mechanism of strand displacement DNA synthesis by the human mitochondrial DNA polymerase, Polγ, and its modulation by cognate and noncognate SSBs. We show that Polγ exhibits a robust DNA unwinding mechanism, which entails lowering the energy barrier for unwinding of the first base pair of the DNA fork junction, by ∼55%. However, the polymerase cannot prevent the reannealing of the parental strands efficiently, which limits by ∼30-fold its strand displacement activity. We demonstrate that SSBs stimulate the Polγ strand displacement activity through several mechanisms. SSB binding energy to ssDNA additionally increases the destabilization energy at the DNA junction, by ∼25%. Furthermore, SSB interactions with the displaced ssDNA reduce the DNA fork reannealing pressure on Polγ, in turn promoting the productive polymerization state by ∼3-fold. These stimulatory effects are enhanced by species-specific functional interactions and have significant implications in the replication of the human mitochondrial DNA.
Collapse
Affiliation(s)
- Ismael Plaza-G A
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Faraday 9, 28049 Madrid, Spain
| | - Kateryna M Lemishko
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Faraday 9, 28049 Madrid, Spain
| | - Rodrigo Crespo
- Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid, Pza. de Ciencias, 1, 28040 Madrid, Spain
| | - Thinh Q Truong
- Department of Chemistry, Auburn University at Montgomery, Montgomery, AL 36117, USA
| | - Laurie S Kaguni
- Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI 48823, USA
| | - Francisco J Cao-García
- Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid, Pza. de Ciencias, 1, 28040 Madrid, Spain
| | - Grzegorz L Ciesielski
- Department of Chemistry, Auburn University at Montgomery, Montgomery, AL 36117, USA.,Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI 48823, USA
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Faraday 9, 28049 Madrid, Spain.,Nanobiotecnología (IMDEA-Nanociencia), Unidad Asociada al Centro Nacional de Biotecnología (CSIC), 28049 Madrid, Spain
| |
Collapse
|
8
|
Xu L, Halma MTJ, Wuite GJL. Unravelling How Single-Stranded DNA Binding Protein Coordinates DNA Metabolism Using Single-Molecule Approaches. Int J Mol Sci 2023; 24:ijms24032806. [PMID: 36769124 PMCID: PMC9917605 DOI: 10.3390/ijms24032806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 01/23/2023] [Accepted: 01/28/2023] [Indexed: 02/05/2023] Open
Abstract
Single-stranded DNA-binding proteins (SSBs) play vital roles in DNA metabolism. Proteins of the SSB family exclusively and transiently bind to ssDNA, preventing the DNA double helix from re-annealing and maintaining genome integrity. In the meantime, they interact and coordinate with various proteins vital for DNA replication, recombination, and repair. Although SSB is essential for DNA metabolism, proteins of the SSB family have been long described as accessory players, primarily due to their unclear dynamics and mechanistic interaction with DNA and its partners. Recently-developed single-molecule tools, together with biochemical ensemble techniques and structural methods, have enhanced our understanding of the different coordination roles that SSB plays during DNA metabolism. In this review, we discuss how single-molecule assays, such as optical tweezers, magnetic tweezers, Förster resonance energy transfer, and their combinations, have advanced our understanding of the binding dynamics of SSBs to ssDNA and their interaction with other proteins partners. We highlight the central coordination role that the SSB protein plays by directly modulating other proteins' activities, rather than as an accessory player. Many possible modes of SSB interaction with protein partners are discussed, which together provide a bigger picture of the interaction network shaped by SSB.
Collapse
|
9
|
Optical Tweezers to Force Information out of Biological and Synthetic Systems One Molecule at a Time. BIOPHYSICA 2022. [DOI: 10.3390/biophysica2040047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Over the last few decades, in vitro single-molecule manipulation techniques have enabled the use of force and displacement as controlled variables in biochemistry. Measuring the effect of mechanical force on the real-time kinetics of a biological process gives us access to the rates, equilibrium constants and free-energy landscapes of the mechanical steps of the reaction; this information is not accessible by ensemble assays. Optical tweezers are the current method of choice in single-molecule manipulation due to their versatility, high force and spatial and temporal resolutions. The aim of this review is to describe the contributions of our lab in the single-molecule manipulation field. We present here several optical tweezers assays refined in our laboratory to probe the dynamics and mechano-chemical properties of biological molecular motors and synthetic molecular devices at the single-molecule level.
Collapse
|
10
|
Valle-Orero J, Rieu M, Tran P, Joubert A, Raj S, Allemand JF, Croquette V, Boulé JB. Strand switching mechanism of Pif1 helicase induced by its collision with a G-quadruplex embedded in dsDNA. Nucleic Acids Res 2022; 50:8767-8778. [PMID: 35947696 PMCID: PMC9410907 DOI: 10.1093/nar/gkac667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 07/01/2022] [Accepted: 07/24/2022] [Indexed: 12/24/2022] Open
Abstract
G-rich sequences found at multiple sites throughout all genomes may form secondary structures called G-quadruplexes (G4), which act as roadblocks for molecular motors. Among the enzymes thought to process these structures, the Pif1 DNA helicase is considered as an archetypical G4-resolvase and its absence has been linked to G4-related genomic instabilities in yeast. Here we developed a single-molecule assay to observe Pif1 opening a DNA duplex and resolving the G4 in real time. In support of former enzymological studies, we show that the helicase reduces the lifetime of G4 from hours to seconds. However, we observe that in the presence of a G4, Pif1 exhibits a strong strand switching behavior, which can lead to Pif1 escaping G4 resolution, depending on the structural context surrounding the substrate. This behavior is also detected in the presence of other roadblocks (LNA or RNA). We propose that the efficiency of Pif1 to remove a roadblock (G4 or other) is affected by its strand switching behavior and depends on the context surrounding the obstacle. We discuss how this switching behavior may explain several aspects of Pif1 substrate preference and affect its activity as a G4 resolvase in vivo.
Collapse
Affiliation(s)
| | - Martin Rieu
- Laboratoire de physique de L’École Normale Supérieure de Paris, CNRS, ENS, Université PSL, Sorbonne Université, Université Paris Cité, 75005 Paris, France,Institut de Biologie de l’École Normale Supérieure de Paris (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Phong Lan Thao Tran
- Structure et Instabilité des Génomes, Museum National d’Histoire Naturelle, INSERM, CNRS, Alliance Sorbonne Université, 75005 Paris, France
| | - Alexandra Joubert
- Structure et Instabilité des Génomes, Museum National d’Histoire Naturelle, INSERM, CNRS, Alliance Sorbonne Université, 75005 Paris, France
| | - Saurabh Raj
- Laboratoire de physique de L’École Normale Supérieure de Paris, CNRS, ENS, Université PSL, Sorbonne Université, Université Paris Cité, 75005 Paris, France
| | - Jean-François Allemand
- Laboratoire de physique de L’École Normale Supérieure de Paris, CNRS, ENS, Université PSL, Sorbonne Université, Université Paris Cité, 75005 Paris, France,Institut de Biologie de l’École Normale Supérieure de Paris (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | | | - Jean-Baptiste Boulé
- To whom correspondence should be addressed. Tel: +33 140795616; Fax: +33 1407937050;
| |
Collapse
|
11
|
Millar DP. Conformational Dynamics of DNA Polymerases Revealed at the Single-Molecule Level. Front Mol Biosci 2022; 9:826593. [PMID: 35281261 PMCID: PMC8913937 DOI: 10.3389/fmolb.2022.826593] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/20/2022] [Indexed: 12/25/2022] Open
Abstract
DNA polymerases are intrinsically dynamic macromolecular machines. The purpose of this review is to describe the single-molecule Förster resonance energy transfer (smFRET) methods that are used to probe the conformational dynamics of DNA polymerases, focusing on E. coli DNA polymerase I. The studies reviewed here reveal the conformational dynamics underpinning the nucleotide selection, proofreading and 5′ nuclease activities of Pol I. Moreover, the mechanisms revealed for Pol I are likely employed across the DNA polymerase family. smFRET methods have also been used to examine other aspects of DNA polymerase activity.
Collapse
|
12
|
DNA Polymerase-Parental DNA Interaction Is Essential for Helicase-Polymerase Coupling during Bacteriophage T7 DNA Replication. Int J Mol Sci 2022; 23:ijms23031342. [PMID: 35163266 PMCID: PMC8835902 DOI: 10.3390/ijms23031342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/19/2022] [Accepted: 01/22/2022] [Indexed: 11/17/2022] Open
Abstract
DNA helicase and polymerase work cooperatively at the replication fork to perform leading-strand DNA synthesis. It was believed that the helicase migrates to the forefront of the replication fork where it unwinds the duplex to provide templates for DNA polymerases. However, the molecular basis of the helicase-polymerase coupling is not fully understood. The recently elucidated T7 replisome structure suggests that the helicase and polymerase sandwich parental DNA and each enzyme pulls a daughter strand in opposite directions. Interestingly, the T7 polymerase, but not the helicase, carries the parental DNA with a positively charged cleft and stacks at the fork opening using a β-hairpin loop. Here, we created and characterized T7 polymerases each with a perturbed β-hairpin loop and positively charged cleft. Mutations on both structural elements significantly reduced the strand-displacement synthesis by T7 polymerase but had only a minor effect on DNA synthesis performed against a linear DNA substrate. Moreover, the aforementioned mutations eliminated synergistic helicase-polymerase binding and unwinding at the DNA fork and processive fork progressions. Thus, our data suggested that T7 polymerase plays a dominant role in helicase-polymerase coupling and replisome progression.
Collapse
|
13
|
Lo CY, Gao Y. Assembling bacteriophage T7 leading-strand replisome for structural investigation. Methods Enzymol 2022; 672:103-123. [PMID: 35934471 DOI: 10.1016/bs.mie.2022.03.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Replicative helicase and polymerase form the leading-strand replisome that unwinds parental DNA and performs continuous leading-strand DNA synthesis. Uncoupling of the helicase-polymerase complex results in replication stress, replication errors, and genome instability. Although numerous replisomes from different biological systems have been reconstituted and characterized, structural investigations of the leading-strand replisome complex are hindered by its large size and dynamics. We have determined the first replisome structure on a fork substrate with bacteriophage T7 replisome as a model system. Here, we summarized our protocols to prepare and characterize the coupled T7 replisome complex. Similar methods can potentially be applied for structural investigations of more complicated replisomes.
Collapse
|
14
|
Singh A, Patel SS. Quantitative methods to study helicase, DNA polymerase, and exonuclease coupling during DNA replication. Methods Enzymol 2022; 672:75-102. [PMID: 35934486 PMCID: PMC9933136 DOI: 10.1016/bs.mie.2022.03.011] [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: 01/31/2023]
Abstract
Genome replication is accomplished by highly regulated activities of enzymes in a multi-protein complex called the replisome. Two major enzymes, DNA polymerase and helicase, catalyze continuous DNA synthesis on the leading strand of the parental DNA duplex while the lagging strand is synthesized discontinuously. The helicase and DNA polymerase on their own are catalytically inefficient and weak motors for unwinding/replicating double-stranded DNA. However, when a helicase and DNA polymerase are functionally and physically coupled, they catalyze fast and highly processive leading strand DNA synthesis. DNA polymerase has a 3'-5' exonuclease activity, which removes nucleotides misincorporated in the nascent DNA. DNA synthesis kinetics, processivity, and accuracy are governed by the interplay of the helicase, DNA polymerase, and exonuclease activities within the replisome. This chapter describes quantitative biochemical and biophysical methods to study the coupling of these three critical activities during DNA replication. The methods include real-time quantitation of kinetics of DNA unwinding-synthesis by a coupled helicase-DNA polymerase complex, a 2-aminopurine fluorescence-based assay to map the precise positions of helicase and DNA polymerase with respect to the replication fork junction, and a radiometric assay to study the coupling of DNA polymerase, exonuclease, and helicase activities during processive leading strand DNA synthesis. These methods are presented here with bacteriophage T7 replication proteins as an example but can be applied to other systems with appropriate modifications.
Collapse
|
15
|
Bocanegra R, Plaza G A I, Ibarra B. In vitro single-molecule manipulation studies of viral DNA replication. Enzymes 2021; 49:115-148. [PMID: 34696830 DOI: 10.1016/bs.enz.2021.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Faithfull replication of genomic information relies on the coordinated activity of the multi-protein machinery known as the replisome. Several constituents of the replisome operate as molecular motors that couple thermal and chemical energy to a mechanical task. Over the last few decades, in vitro single-molecule manipulation techniques have been used to monitor and manipulate mechanically the activities of individual molecular motors involved in DNA replication with nanometer, millisecond, and picoNewton resolutions. These studies have uncovered the real-time kinetics of operation of these biological systems, the nature of their transient intermediates, and the processes by which they convert energy to work (mechano-chemistry), ultimately providing new insights into their inner workings of operation not accessible by ensemble assays. In this chapter, we describe two of the most widely used single-molecule manipulation techniques for the study of DNA replication, optical and magnetic tweezers, and their application in the study of the activities of proteins involved in viral DNA replication.
Collapse
Affiliation(s)
- Rebeca Bocanegra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Madrid, Spain
| | - Ismael Plaza G A
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Madrid, Spain
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Madrid, Spain.
| |
Collapse
|
16
|
Spinks RR, Spenkelink LM, Dixon NE, van Oijen AM. Single-Molecule Insights Into the Dynamics of Replicative Helicases. Front Mol Biosci 2021; 8:741718. [PMID: 34513934 PMCID: PMC8426354 DOI: 10.3389/fmolb.2021.741718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 08/13/2021] [Indexed: 11/13/2022] Open
Abstract
Helicases are molecular motors that translocate along single-stranded DNA and unwind duplex DNA. They rely on the consumption of chemical energy from nucleotide hydrolysis to drive their translocation. Specialized helicases play a critically important role in DNA replication by unwinding DNA at the front of the replication fork. The replicative helicases of the model systems bacteriophages T4 and T7, Escherichia coli and Saccharomyces cerevisiae have been extensively studied and characterized using biochemical methods. While powerful, their averaging over ensembles of molecules and reactions makes it challenging to uncover information related to intermediate states in the unwinding process and the dynamic helicase interactions within the replisome. Here, we describe single-molecule methods that have been developed in the last few decades and discuss the new details that these methods have revealed about replicative helicases. Applying methods such as FRET and optical and magnetic tweezers to individual helicases have made it possible to access the mechanistic aspects of unwinding. It is from these methods that we understand that the replicative helicases studied so far actively translocate and then passively unwind DNA, and that these hexameric enzymes must efficiently coordinate the stepping action of their subunits to achieve unwinding, where the size of each step is prone to variation. Single-molecule fluorescence microscopy methods have made it possible to visualize replicative helicases acting at replication forks and quantify their dynamics using multi-color colocalization, FRAP and FLIP. These fluorescence methods have made it possible to visualize helicases in replication initiation and dissect this intricate protein-assembly process. In a similar manner, single-molecule visualization of fluorescent replicative helicases acting in replication identified that, in contrast to the replicative polymerases, the helicase does not exchange. Instead, the replicative helicase acts as the stable component that serves to anchor the other replication factors to the replisome.
Collapse
Affiliation(s)
- Richard R Spinks
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - Lisanne M Spenkelink
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - Nicholas E Dixon
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - Antoine M van Oijen
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| |
Collapse
|
17
|
Lo CY, Gao Y. DNA Helicase-Polymerase Coupling in Bacteriophage DNA Replication. Viruses 2021; 13:v13091739. [PMID: 34578319 PMCID: PMC8472574 DOI: 10.3390/v13091739] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 12/28/2022] Open
Abstract
Bacteriophages have long been model systems to study the molecular mechanisms of DNA replication. During DNA replication, a DNA helicase and a DNA polymerase cooperatively unwind the parental DNA. By surveying recent data from three bacteriophage replication systems, we summarized the mechanistic basis of DNA replication by helicases and polymerases. Kinetic data have suggested that a polymerase or a helicase alone is a passive motor that is sensitive to the base-pairing energy of the DNA. When coupled together, the helicase-polymerase complex is able to unwind DNA actively. In bacteriophage T7, helicase and polymerase reside right at the replication fork where the parental DNA is separated into two daughter strands. The two motors pull the two daughter strands to opposite directions, while the polymerase provides a separation pin to split the fork. Although independently evolved and containing different replisome components, bacteriophage T4 replisome shares mechanistic features of Hel-Pol coupling that are similar to T7. Interestingly, in bacteriophages with a limited size of genome like Φ29, DNA polymerase itself can form a tunnel-like structure, which encircles the DNA template strand and facilitates strand displacement synthesis in the absence of a helicase. Studies on bacteriophage replication provide implications for the more complicated replication systems in bacteria, archaeal, and eukaryotic systems, as well as the RNA genome replication in RNA viruses.
Collapse
Affiliation(s)
| | - Yang Gao
- Correspondence: ; Tel.: +1-713-348-2619
| |
Collapse
|
18
|
The nucleotide addition cycle of the SARS-CoV-2 polymerase. Cell Rep 2021; 36:109650. [PMID: 34433083 PMCID: PMC8367775 DOI: 10.1016/j.celrep.2021.109650] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/10/2021] [Accepted: 08/11/2021] [Indexed: 12/29/2022] Open
Abstract
Coronaviruses have evolved elaborate multisubunit machines to replicate and transcribe their genomes. Central to these machines are the RNA-dependent RNA polymerase subunit (nsp12) and its intimately associated cofactors (nsp7 and nsp8). We use a high-throughput magnetic-tweezers approach to develop a mechanochemical description of this core polymerase. The core polymerase exists in at least three catalytically distinct conformations, one being kinetically consistent with incorporation of incorrect nucleotides. We provide evidence that the RNA-dependent RNA polymerase (RdRp) uses a thermal ratchet instead of a power stroke to transition from the pre- to post-translocated state. Ultra-stable magnetic tweezers enable the direct observation of coronavirus polymerase deep and long-lived backtracking that is strongly stimulated by secondary structures in the template. The framework we present here elucidates one of the most important structure-dynamics-function relationships in human health today and will form the grounds for understanding the regulation of this complex.
Collapse
|
19
|
Zhang S, Xiao X, Kong J, Lu K, Dou SX, Wang PY, Ma L, Liu Y, Li G, Li W, Zhang H. DNA polymerase Gp90 activities and regulations on strand displacement DNA synthesis revealed at single-molecule level. FASEB J 2021; 35:e21607. [PMID: 33908664 DOI: 10.1096/fj.202100033rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/18/2021] [Accepted: 04/05/2021] [Indexed: 11/11/2022]
Abstract
Strand displacement DNA synthesis (SDDS) is an essential step in DNA replication. With magnetic tweezers, we investigated SDDS kinetics of wild-type gp90 and its exonuclease-deficient polymerase gp90 exo- at single-molecule level. A novel binding state of gp90 to the fork flap was confirmed prior to SDDS, suggesting an intermediate in the initiation of SDDS. The rate and processivity of SDDS by gp90 exo- or wt-gp90 are increased with force and dNTP concentration. The rate and processivity of exonuclease by wt-gp90 are decreased with force. High GC content decreases SDDS and exonuclease processivity but increases exonuclease rate for wt-gp90. The high force and dNTP concentration and low GC content facilitate the successive SDDS but retard the successive exonuclease for wt-gp90. Furthermore, increasing GC content accelerates the transition from SDDS or exonuclease to exonuclease. This work reveals the kinetics of SDDS in detail and offers a broader cognition on the regulation of various factors on SDDS at single-polymerase level.
Collapse
Affiliation(s)
- Shuming Zhang
- Key Laboratory of Environment and Female Reproductive Health, West China School of Public Health & West China Fourth Hospital, Sichuan University, Chengdu, China.,National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Xue Xiao
- National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jingwei Kong
- National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Ke Lu
- National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Shuo-Xing Dou
- National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Peng-Ye Wang
- National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China.,Songshan Lake Materials Laboratory, Dongguan, China
| | - Lu Ma
- National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Yuru Liu
- National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Guohong Li
- National Laboratory of Biomacromolecules, CAS Centre for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Wei Li
- National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.,Songshan Lake Materials Laboratory, Dongguan, China
| | - Huidong Zhang
- Key Laboratory of Environment and Female Reproductive Health, West China School of Public Health & West China Fourth Hospital, Sichuan University, Chengdu, China.,Research Center for Environment and Female Reproductive Health, the Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| |
Collapse
|
20
|
Jarillo J, Ibarra B, Cao-García FJ. DNA replication: In vitro single-molecule manipulation data analysis and models. Comput Struct Biotechnol J 2021; 19:3765-3778. [PMID: 34285777 PMCID: PMC8267548 DOI: 10.1016/j.csbj.2021.06.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 11/05/2022] Open
Abstract
Data analysis allows to extract information from the noisy single-molecule data. Models provide insight in the underlying biochemical processes. Ligands can activate or inhibit DNA replication and DNA unwinding.
DNA replication is a key biochemical process of the cell cycle. In the last years, analysis of in vitro single-molecule DNA replication events has provided new information that cannot be obtained with ensembles studies. Here, we introduce crucial techniques for the proper analysis and modelling of DNA replication in vitro single-molecule manipulation data. Specifically, we review some of the main methods to analyze and model the real-time kinetics of the two main molecular motors of the replisome: DNA polymerase and DNA helicase. Our goal is to facilitate access to and understanding of these techniques to promotetheir use in the study of DNA replication at the single-molecule level. A proper analysis of single-molecule data is crucial to obtain a detailed picture of, among others, the kinetics rates, equilibrium contants and conformational changes of the system under study. The techniques presented here have been used or can be adapted to study the operation of other proteins involved in nucleic acids metabolism.
Collapse
Affiliation(s)
- Javier Jarillo
- University of Namur, Institute of Life-Earth-Environment, Namur Center for Complex Systems, Rue de Bruxelles 61, 5000 Namur, Belgium
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, C/ Faraday 9, 28049 Madrid, Spain
| | - Francisco Javier Cao-García
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, C/ Faraday 9, 28049 Madrid, Spain.,Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid, Pza. de Ciencias, 1, 28040 Madrid, Spain
| |
Collapse
|
21
|
Measurements of Real-Time Replication Kinetics of DNA Polymerases on ssDNA Templates Coated with Single-Stranded DNA-Binding Proteins. Methods Mol Biol 2021; 2281:289-301. [PMID: 33847966 DOI: 10.1007/978-1-0716-1290-3_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Optical tweezers can monitor and control the activity of individual DNA polymerase molecules in real time, providing in this way unprecedented insight into the complex dynamics and mechanochemical processes that govern their operation. Here, we describe an optical tweezers-based assay to determine at the single-molecule level the effect of single-stranded DNA-binding proteins (SSB) on the real-time replication kinetics of the human mitochondrial DNA polymerase during the synthesis of the lagging strand.
Collapse
|
22
|
Magnetic Tweezers-Based Single-Molecule Assays to Study Interaction of E. coli SSB with DNA and RecQ Helicase. Methods Mol Biol 2021; 2281:93-115. [PMID: 33847954 DOI: 10.1007/978-1-0716-1290-3_6] [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: 02/04/2023]
Abstract
The ability of magnetic tweezers to apply forces and measure molecular displacements has resulted in its extensive use to study the activity of enzymes involved in various aspects of nucleic acid metabolism. These studies have led to the discovery of key aspects of protein-protein and protein-nucleic acid interaction, uncovering dynamic heterogeneities that are lost to ensemble averaging in bulk experiments. The versatility of magnetic tweezers lies in the possibility and ease of tracking multiple parallel single-molecule events to yield statistically relevant single-molecule data. Moreover, they allow tracking both fast millisecond dynamics and slow processes (spanning several hours). In this chapter, we present the protocols used to study the interaction between E. coli SSB, single-stranded DNA (ssDNA), and E. coli RecQ helicase using magnetic tweezers. In particular, we propose constant force and force modulation assays to investigate SSB binding to DNA, as well as to characterize various facets of RecQ helicase activity stimulation by SSB.
Collapse
|
23
|
Benkovic SJ. From Bioorganic Models to Cells. Annu Rev Biochem 2021; 90:57-76. [PMID: 34153218 DOI: 10.1146/annurev-biochem-062320-062929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
I endeavor to share how various choices-some deliberate, some unconscious-and the unmistakable influence of many others shaped my scientific pursuits. I am fascinated by how two long-term, major streams of my research, DNA replication and purine biosynthesis, have merged with unexpected interconnections. If I have imparted to many of the talented individuals who have passed through my lab a degree of my passion for uncloaking the mysteries hidden in scientific research and an understanding of the honesty and rigor it demands and its impact on the world community, then my mentorship has been successful.
Collapse
Affiliation(s)
- Stephen J Benkovic
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA;
| |
Collapse
|
24
|
Bocanegra R, Ismael Plaza GA, Pulido CR, Ibarra B. DNA replication machinery: Insights from in vitro single-molecule approaches. Comput Struct Biotechnol J 2021; 19:2057-2069. [PMID: 33995902 PMCID: PMC8085672 DOI: 10.1016/j.csbj.2021.04.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/03/2021] [Accepted: 04/03/2021] [Indexed: 11/16/2022] Open
Abstract
The replisome is the multiprotein molecular machinery that replicates DNA. The replisome components work in precise coordination to unwind the double helix of the DNA and replicate the two strands simultaneously. The study of DNA replication using in vitro single-molecule approaches provides a novel quantitative understanding of the dynamics and mechanical principles that govern the operation of the replisome and its components. ‘Classical’ ensemble-averaging methods cannot obtain this information. Here we describe the main findings obtained with in vitro single-molecule methods on the performance of individual replisome components and reconstituted prokaryotic and eukaryotic replisomes. The emerging picture from these studies is that of stochastic, versatile and highly dynamic replisome machinery in which transient protein-protein and protein-DNA associations are responsible for robust DNA replication.
Collapse
Affiliation(s)
- Rebeca Bocanegra
- IMDEA Nanociencia, Faraday 9, Campus Cantoblanco, 28049 Madrid, Spain
| | - G A Ismael Plaza
- IMDEA Nanociencia, Faraday 9, Campus Cantoblanco, 28049 Madrid, Spain
| | - Carlos R Pulido
- IMDEA Nanociencia, Faraday 9, Campus Cantoblanco, 28049 Madrid, Spain
| | - Borja Ibarra
- IMDEA Nanociencia, Faraday 9, Campus Cantoblanco, 28049 Madrid, Spain
| |
Collapse
|
25
|
Bera SC, Seifert M, Kirchdoerfer RN, van Nies P, Wubulikasimu Y, Quack S, Papini FS, Arnold JJ, Canard B, Cameron CE, Depken M, Dulin D. The nucleotide addition cycle of the SARS-CoV-2 polymerase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2021.03.27.437309. [PMID: 33791706 PMCID: PMC8010733 DOI: 10.1101/2021.03.27.437309] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Coronaviruses have evolved elaborate multisubunit machines to replicate and transcribe their genomes. Central to these machines are the RNA-dependent RNA polymerase subunit (nsp12) and its intimately associated cofactors (nsp7 and nsp8). We have used a high-throughput magnetic-tweezers approach to develop a mechanochemical description of this core polymerase. The core polymerase exists in at least three catalytically distinct conformations, one being kinetically consistent with incorporation of incorrect nucleotides. We provide the first evidence that an RdRp uses a thermal ratchet instead of a power stroke to transition from the pre- to post-translocated state. Ultra-stable magnetic tweezers enables the direct observation of coronavirus polymerase deep and long-lived backtrack that are strongly stimulated by secondary structure in the template. The framework presented here elucidates one of the most important structure-dynamics-function relationships in human health today, and will form the grounds for understanding the regulation of this complex.
Collapse
Affiliation(s)
- Subhas Chandra Bera
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Mona Seifert
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Robert N. Kirchdoerfer
- Department of Biochemistry and Institute for Molecular Virology, University of Wisconsin-Madison, Madison, WI 53706
| | - Pauline van Nies
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Yibulayin Wubulikasimu
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Salina Quack
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Flávia S. Papini
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
| | - Jamie J. Arnold
- Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC 27599 USA
| | - Bruno Canard
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Aix-Marseille Université, UMR 7257, Polytech Case 925, 13009 Marseille, France
| | - Craig E. Cameron
- Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC 27599 USA
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - David Dulin
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Cauerstr. 3, 91058 Erlangen, Germany
- Department of Physics and Astronomy, and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| |
Collapse
|
26
|
Zhou X, Chen X, An Y, Lu H, Wang L, Xu H, Tian B, Zhao Y, Hua Y. Biochemical characterization of a unique DNA polymerase A from the extreme radioresistant organism Deinococcus radiodurans. Biochimie 2021; 185:22-32. [PMID: 33727139 DOI: 10.1016/j.biochi.2021.02.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/30/2021] [Accepted: 02/19/2021] [Indexed: 01/07/2023]
Abstract
Deinococcus radiodurans survives extraordinary doses of ionizing radiation and desiccation that cause numerous DNA strand breaks. D. radiodurans DNA polymerase A (DrPolA) is essential for reassembling the shattered genome, while its biochemical property has not been fully demonstrated. In this study, we systematically examined the enzymatic activities of DrPolA and characterized its unique features. DrPolA contains an N-terminal nuclease domain (DrPolA-NTD) and a C-terminal Klenow fragment (KlenDr). Compared with the Klenow fragment of E. coli Pol I, KlenDr shows higher fidelity despite the lacking of 3'-5' exonuclease proofreading activity and prefers double-strand DNA rather than Primer-Template substrates. Apart from the well-annotated 5'-3' exonuclease and flap endonuclease activities, DrPolA-NTD displays approximately 140-fold higher gap endonuclease activity than its homolog in E. coli and Human FEN1. Its 5'-3' exonuclease activity on ssDNA, gap endonuclease, and Holliday junction cleavage activities are greatly enhanced by Mn2+. The DrPolA-NTD deficient strain shows increased sensitivity to UV and gamma-ray radiation. Collectively, our results reveal distinct biochemical characteristics of DrPolA during DNA degradation and re-synthesis, which provide new insight into the outstanding DNA repair capacity of D. radiodurans.
Collapse
Affiliation(s)
- Xingru Zhou
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Biophysics, College of Life Sciences, Zhejiang University, China
| | - Xuanyi Chen
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Biophysics, College of Life Sciences, Zhejiang University, China
| | - Ying An
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Biophysics, College of Life Sciences, Zhejiang University, China
| | - Huizhi Lu
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Biophysics, College of Life Sciences, Zhejiang University, China
| | - Liangyan Wang
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Biophysics, College of Life Sciences, Zhejiang University, China
| | - Hong Xu
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Biophysics, College of Life Sciences, Zhejiang University, China
| | - Bing Tian
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Biophysics, College of Life Sciences, Zhejiang University, China
| | - Ye Zhao
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Biophysics, College of Life Sciences, Zhejiang University, China
| | - Yuejin Hua
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Institute of Biophysics, College of Life Sciences, Zhejiang University, China.
| |
Collapse
|
27
|
Wang Z, Maluenda J, Giraut L, Vieille T, Lefevre A, Salthouse D, Radou G, Moulinas R, Astete S, D'Avezac P, Smith G, André C, Allemand JF, Bensimon D, Croquette V, Ouellet J, Hamilton G. Detection of genetic variation and base modifications at base-pair resolution on both DNA and RNA. Commun Biol 2021; 4:128. [PMID: 33514840 PMCID: PMC7846774 DOI: 10.1038/s42003-021-01648-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 12/28/2020] [Indexed: 11/14/2022] Open
Abstract
Accurate decoding of nucleic acid variation is critical to understand the complexity and regulation of genome function. Here we use a single-molecule magnetic tweezer (MT) platform to identify sequence variation and map a range of important epigenetic base modifications with high sensitivity, specificity, and precision in the same single molecules of DNA or RNA. We have also developed a highly specific amplification-free CRISPR-Cas enrichment strategy to isolate genomic regions from native DNA. We demonstrate enrichment of DNA from both E. coli and the FMR1 5'UTR coming from cells derived from a Fragile X carrier. From these kilobase-length enriched molecules we could characterize the differential levels of adenine and cytosine base modifications on E. coli, and the repeat expansion length and methylation status of FMR1. Together these results demonstrate that our platform can detect a variety of genetic, epigenetic, and base modification changes concomitantly within the same single molecules.
Collapse
Affiliation(s)
- Zhen Wang
- Depixus SAS, 3/5 Impasse Reille, 75014, Paris, France
| | | | | | | | | | | | - Gaël Radou
- Depixus SAS, 3/5 Impasse Reille, 75014, Paris, France
| | - Rémi Moulinas
- Depixus SAS, 3/5 Impasse Reille, 75014, Paris, France
| | - Sandra Astete
- Depixus SAS, 3/5 Impasse Reille, 75014, Paris, France
| | - Pol D'Avezac
- Depixus SAS, 3/5 Impasse Reille, 75014, Paris, France
| | - Geoff Smith
- Depixus SAS, 3/5 Impasse Reille, 75014, Paris, France
| | - Charles André
- Depixus SAS, 3/5 Impasse Reille, 75014, Paris, France
| | - Jean-François Allemand
- Laboratoire de physique de L'École normale supérieure de Paris, CNRS, ENS, Université PSL, Sorbonne Université, Université de Paris, Paris, 75005, France
- IBENS, Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University, 75005, Paris, France
| | - David Bensimon
- Laboratoire de physique de L'École normale supérieure de Paris, CNRS, ENS, Université PSL, Sorbonne Université, Université de Paris, Paris, 75005, France
- IBENS, Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University, 75005, Paris, France
- Department of Chemistry and Biochemistry, UCLA, 607 Charles E Young Drive East, Los Angeles, 90095, USA
| | - Vincent Croquette
- Laboratoire de physique de L'École normale supérieure de Paris, CNRS, ENS, Université PSL, Sorbonne Université, Université de Paris, Paris, 75005, France
- IBENS, Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University, 75005, Paris, France
- ESPCI Paris, PSL University, 10 rue Vauquelin, 75005, Paris, France
| | - Jimmy Ouellet
- Depixus SAS, 3/5 Impasse Reille, 75014, Paris, France
| | | |
Collapse
|
28
|
Prasannakumar MK, Parivallal BP, Manjunatha C, Pramesh D, Narayan KS, Venkatesh G, Banakar SN, Mahesh HB, Vemanna RS, Rangaswamy KT. Rapid genotyping of bacterial leaf blight resistant genes of rice using loop-mediated isothermal amplification assay. Mol Biol Rep 2021; 48:467-474. [PMID: 33394228 DOI: 10.1007/s11033-020-06077-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 12/10/2020] [Indexed: 01/15/2023]
Abstract
The use of resistant (R) genes is the most effective strategy to manage bacterial leaf blight (BLB) disease of rice. Several attempts were made to incorporate R genes into susceptible rice cultivars using marker-assisted backcross breeding (MABB). However, MABB relies exclusively on PCR for foreground selection of R genes, which requires expensive equipment for thermo-cycling and visualization of results; hence, it is limited to sophisticated research facilities. Isothermal nucleic acid amplification techniques such as loop-mediated isothermal amplification (LAMP) assay do not require thermo-cycling during the assay. Therefore, it will be the best alternative to PCR-based genotyping. In this study, we have developed a LAMP assay for the specific and sensitive genotyping of seven BLB resistance (R) genes viz., Xa1, Xa3, Xa4, Xa7, Xa10, Xa11, and Xa21 in rice. Gene-specific primers were designed for the LAMP assay. The LAMP assay was optimized for time, temperature, and template DNA concentration. For effective detection, incubation at 60 °C for 30 min was optimum for all seven R genes. A DNA intercalating dye ethidium bromide and a calorimetric dye hydroxynaphthol blue was used for result visualization. Further, sensitivity assay revealed that the LAMP assay could detect R genes at 100 fg of template DNA compared to 1 ng and 10 pg, respectively, in conventional PCR and q-PCR assays. The LAMP assay developed in this study provides a simple, specific, sensitive, robust, and cost-effective method for foreground selection of R genes in the resistance breeding programs of resource-poor laboratory.
Collapse
Affiliation(s)
- M K Prasannakumar
- Department of Plant Pathology, University of Agricultural Sciences, Bangalore, India.
| | - Buela P Parivallal
- Department of Plant Pathology, University of Agricultural Sciences, Bangalore, India
| | - Chennappa Manjunatha
- ICAR-Indian Agricultural Research Institute, Regional Station Wellington, Nilgiris, Tamil Nadu, India
| | - Devanna Pramesh
- Rice Pathology Laboratory, All India Coordinated Rice Improvement Programme, Gangavathi, University of Agricultural Sciences, Raichur, Karnataka, India.
| | - Karthik S Narayan
- Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai, India
| | - Gopal Venkatesh
- Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai, India
| | - Sahana N Banakar
- Department of Plant Pathology, University of Agricultural Sciences, Bangalore, India
| | - H B Mahesh
- Department of Genetics and Plant Breeding, University of Agricultural Sciences, Bangalore, Karnataka, India
| | - Ramu S Vemanna
- Department of Biotechnology, Regional Centre for Biotechnology, Gurgaon, Haryana, India
| | - K T Rangaswamy
- Department of Plant Pathology, University of Agricultural Sciences, Bangalore, India
| |
Collapse
|
29
|
Zhang H. Mechanisms of mutagenesis induced by DNA lesions: multiple factors affect mutations in translesion DNA synthesis. Crit Rev Biochem Mol Biol 2020; 55:219-251. [PMID: 32448001 DOI: 10.1080/10409238.2020.1768205] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Environmental mutagens lead to mutagenesis. However, the mechanisms are very complicated and not fully understood. Environmental mutagens produce various DNA lesions, including base-damaged or sugar-modified DNA lesions, as well as epigenetically modified DNA. DNA polymerases produce mutation spectra in translesion DNA synthesis (TLS) through misincorporation of incorrect nucleotides, frameshift deletions, blockage of DNA replication, imbalance of leading- and lagging-strand DNA synthesis, and genome instability. Motif or subunit in DNA polymerases further affects the mutations in TLS. Moreover, protein interactions and accessory proteins in DNA replisome also alter mutations in TLS, demonstrated by several representative DNA replisomes. Finally, in cells, multiple DNA polymerases or cellular proteins collaborate in TLS and reduce in vivo mutagenesis. Summaries and perspectives were listed. This review shows mechanisms of mutagenesis induced by DNA lesions and the effects of multiple factors on mutations in TLS in vitro and in vivo.
Collapse
Affiliation(s)
- Huidong Zhang
- Key Laboratory of Environment and Female Reproductive Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| |
Collapse
|
30
|
Papini FS, Seifert M, Dulin D. High-yield fabrication of DNA and RNA constructs for single molecule force and torque spectroscopy experiments. Nucleic Acids Res 2020; 47:e144. [PMID: 31584079 PMCID: PMC6902051 DOI: 10.1093/nar/gkz851] [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: 06/05/2019] [Revised: 08/20/2019] [Accepted: 10/02/2019] [Indexed: 12/19/2022] Open
Abstract
Single molecule biophysics experiments have enabled the observation of biomolecules with a great deal of precision in space and time, e.g. nucleic acids mechanical properties and protein–nucleic acids interactions using force and torque spectroscopy techniques. The success of these experiments strongly depends on the capacity of the researcher to design and fabricate complex nucleic acid structures, as the outcome and the yield of the experiment also strongly depend on the high quality and purity of the final construct. Though the molecular biology techniques involved are well known, the fabrication of nucleic acid constructs for single molecule experiments still remains a difficult task. Here, we present new protocols to generate high quality coilable double-stranded DNA and RNA, as well as DNA and RNA hairpins with ∼500–1000 bp long stems. Importantly, we present a new approach based on single-stranded DNA (ssDNA) annealing and we use magnetic tweezers to show that this approach simplifies the fabrication of complex DNA constructs, such as hairpins, and converts more efficiently the input DNA into construct than the standard PCR-digestion-ligation approach. The protocols we describe here enable the design of a large range of nucleic acid construct for single molecule biophysics experiments.
Collapse
Affiliation(s)
- Flávia S Papini
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Cauerstrasse 3, 91058 Erlangen, Germany
| | - Mona Seifert
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Cauerstrasse 3, 91058 Erlangen, Germany
| | - David Dulin
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Cauerstrasse 3, 91058 Erlangen, Germany
| |
Collapse
|
31
|
Mi C, Zhang S, Huang W, Dai M, Chai Z, Yang W, Deng S, Ao L, Zhang H. Strand displacement DNA synthesis by DNA polymerase gp90 exo - of Pseudomonas aeruginosa phage 1. Biochimie 2020; 170:73-87. [PMID: 31911177 DOI: 10.1016/j.biochi.2019.12.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 12/31/2019] [Indexed: 12/27/2022]
Abstract
Strand displacement DNA synthesis is essential for DNA replication. Gp90, the sole DNA polymerase of Pseudomonas aeruginosa phage 1, can bypass multiply DNA lesions. However, whether it can perform strand displacement synthesis is still unknown. In this work, we found that gp90 exo- could perform strand displacement synthesis, albeit its activity and processivity were lower than those of primer extension. Gp90 exo- itself could not unwind Y-shaped or fork DNA. Tail and gap at DNA fork were necessary for efficient synthesis. High GC content obviously inhibited strand displacement synthesis. Consecutive GC sequence at the entrance of fork showed more inhibition effect on DNA synthesis than that in the downstream DNA fork. The fraction of productive polymerase and DNA complex (A values) was higher for fork than gap; while their average extension rates (kp values) were similar. However, both A and kp values were lower than those for the primer/template (P/T) substrate. The binding of gp90 exo- to fork was tighter than P/T or gap in the absence of dATP. In the presence of dATP to form ternary complex, the binding affinity of gp90 exo- to P/T or gap was increased compared with that in the binary complex. Abasic site, 8-oxoG, and O6-MeG inhibited and even blocked strand displacement synthesis. This work shows that gp90 exo- could perform strand displacement DNA synthesis at DNA fork, discovering the presence of new functions of PaP1 DNA polymerase in DNA replication and propagation of PaP1.
Collapse
Affiliation(s)
- Chenyang Mi
- Key Laboratory of Environment and Female Reproductive Health, West China School of Public Health & West China Fourth Hospital, Sichuan University, Chengdu, 610041, China
| | - Shuming Zhang
- Key Laboratory of Environment and Female Reproductive Health, West China School of Public Health & West China Fourth Hospital, Sichuan University, Chengdu, 610041, China
| | - Wenxin Huang
- Key Laboratory of Environment and Female Reproductive Health, West China School of Public Health & West China Fourth Hospital, Sichuan University, Chengdu, 610041, China
| | - Mengyuan Dai
- Key Laboratory of Environment and Female Reproductive Health, West China School of Public Health & West China Fourth Hospital, Sichuan University, Chengdu, 610041, China
| | - Zili Chai
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China
| | - Wang Yang
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China
| | - Shanshan Deng
- Non-Coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, 610500, China
| | - Lin Ao
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, PR China.
| | - Huidong Zhang
- Key Laboratory of Environment and Female Reproductive Health, West China School of Public Health & West China Fourth Hospital, Sichuan University, Chengdu, 610041, China.
| |
Collapse
|
32
|
Cerrón F, de Lorenzo S, Lemishko KM, Ciesielski GL, Kaguni LS, Cao FJ, Ibarra B. Replicative DNA polymerases promote active displacement of SSB proteins during lagging strand synthesis. Nucleic Acids Res 2019; 47:5723-5734. [PMID: 30968132 PMCID: PMC6582349 DOI: 10.1093/nar/gkz249] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 03/22/2019] [Accepted: 03/29/2019] [Indexed: 11/23/2022] Open
Abstract
Genome replication induces the generation of large stretches of single-stranded DNA (ssDNA) intermediates that are rapidly protected by single-stranded DNA-binding (SSB) proteins. To date, the mechanism by which tightly bound SSBs are removed from ssDNA by the lagging strand DNA polymerase without compromising the advance of the replication fork remains unresolved. Here, we aimed to address this question by measuring, with optical tweezers, the real-time replication kinetics of the human mitochondrial and bacteriophage T7 DNA polymerases on free-ssDNA, in comparison with ssDNA covered with homologous and non-homologous SSBs under mechanical tension. We find important differences between the force dependencies of the instantaneous replication rates of each polymerase on different substrates. Modeling of the data supports a mechanism in which strong, specific polymerase-SSB interactions, up to ∼12 kBT, are required for the polymerase to dislodge SSB from the template without compromising its instantaneous replication rate, even under stress conditions that may affect SSB–DNA organization and/or polymerase–SSB communication. Upon interaction, the elimination of template secondary structure by SSB binding facilitates the maximum replication rate of the lagging strand polymerase. In contrast, in the absence of polymerase–SSB interactions, SSB poses an effective barrier for the advance of the polymerase, slowing down DNA synthesis.
Collapse
Affiliation(s)
- Fernando Cerrón
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia. 28049 Madrid, Spain.,Departamento Estructura de la Materia, Física Térmica y Electrónica. Universidad Complutense. 28040 Madrid, Spain
| | - Sara de Lorenzo
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia. 28049 Madrid, Spain
| | - Kateryna M Lemishko
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia. 28049 Madrid, Spain.,Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia) & CNB-CSIC-IMDEA Nanociencia Associated Unit "Unidad de Nanobiotecnología". 28049 Madrid, Spain
| | - Grzegorz L Ciesielski
- Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI 48823, USA
| | - Laurie S Kaguni
- Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI 48823, USA
| | - Francisco J Cao
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia. 28049 Madrid, Spain.,Departamento Estructura de la Materia, Física Térmica y Electrónica. Universidad Complutense. 28040 Madrid, Spain
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia. 28049 Madrid, Spain.,Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia) & CNB-CSIC-IMDEA Nanociencia Associated Unit "Unidad de Nanobiotecnología". 28049 Madrid, Spain
| |
Collapse
|
33
|
Parallelized DNA tethered bead measurements to scrutinize DNA mechanical structure. Methods 2019; 169:46-56. [PMID: 31351926 DOI: 10.1016/j.ymeth.2019.07.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 07/01/2019] [Accepted: 07/22/2019] [Indexed: 01/05/2023] Open
Abstract
Tethering beads to DNA offers a panel of single molecule techniques for the refined analysis of the conformational dynamics of DNA and the elucidation of the mechanisms of enzyme activity. Recent developments include the massive parallelization of these techniques achieved by the fabrication of dedicated nanoarrays by soft nanolithography. We focus here on two of these techniques: the Tethered Particle motion and Magnetic Tweezers allowing analysis of the behavior of individual DNA molecules in the absence of force and under the application of a force and/or a torque, respectively. We introduce the experimental protocols for the parallelization and discuss the benefits already gained, and to come, for these single molecule investigations.
Collapse
|
34
|
Zananiri R, Malik O, Rudnizky S, Gaydar V, Kreiserman R, Henn A, Kaplan A. Synergy between RecBCD subunits is essential for efficient DNA unwinding. eLife 2019; 8:e40836. [PMID: 30601118 PMCID: PMC6338465 DOI: 10.7554/elife.40836] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 01/01/2019] [Indexed: 12/12/2022] Open
Abstract
The subunits of the bacterial RecBCD act in coordination, rapidly and processively unwinding DNA at the site of a double strand break. RecBCD is able to displace DNA-binding proteins, suggesting that it generates high forces, but the specific role of each subunit in the force generation is unclear. Here, we present a novel optical tweezers assay that allows monitoring the activity of RecBCD's individual subunits, when they are part of an intact full complex. We show that RecBCD and its subunits are able to generate forces up to 25-40 pN without a significant effect on their velocity. Moreover, the isolated RecD translocates fast but is a weak helicase with limited processivity. Experiments at a broad range of [ATP] and forces suggest that RecD unwinds DNA as a Brownian ratchet, rectified by ATP binding, and that the presence of the other subunits shifts the ratchet equilibrium towards the post-translocation state.
Collapse
Affiliation(s)
- Rani Zananiri
- Faculty of BiologyTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Omri Malik
- Faculty of BiologyTechnion – Israel Institute of TechnologyHaifaIsrael
- Russell Berrie Nanotechnology InstituteTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Sergei Rudnizky
- Faculty of BiologyTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Vera Gaydar
- Faculty of BiologyTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Roman Kreiserman
- Faculty of BiologyTechnion – Israel Institute of TechnologyHaifaIsrael
- Faculty of PhysicsTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Arnon Henn
- Faculty of BiologyTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Ariel Kaplan
- Faculty of BiologyTechnion – Israel Institute of TechnologyHaifaIsrael
| |
Collapse
|
35
|
Ostrofet E, Papini FS, Dulin D. Correction-free force calibration for magnetic tweezers experiments. Sci Rep 2018; 8:15920. [PMID: 30374099 PMCID: PMC6206022 DOI: 10.1038/s41598-018-34360-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 10/12/2018] [Indexed: 11/09/2022] Open
Abstract
Magnetic tweezers are a powerful technique to perform high-throughput and high-resolution force spectroscopy experiments at the single-molecule level. The camera-based detection of magnetic tweezers enables the observation of hundreds of magnetic beads in parallel, and therefore the characterization of the mechanochemical behavior of hundreds of nucleic acids and enzymes. However, magnetic tweezers experiments require an accurate force calibration to extract quantitative data, which is limited to low forces if the deleterious effect of the finite camera open shutter time (τsh) is not corrected. Here, we provide a simple method to perform correction-free force calibration for high-throughput magnetic tweezers at low image acquisition frequency (fac). By significantly reducing τsh to at least 4-fold the characteristic times of the tethered magnetic bead, we accurately evaluated the variance of the magnetic bead position along the axis parallel to the magnetic field, estimating the force with a relative error of ~10% (standard deviation), being only limited by the bead-to-bead difference. We calibrated several magnets - magnetic beads configurations, covering a force range from ~50 fN to ~60 pN. In addition, for the presented configurations, we provide a table with the mathematical expressions that describe the force as a function of the magnets position.
Collapse
Affiliation(s)
- Eugen Ostrofet
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Hartmannstr. 14, 91052, Erlangen, Germany
| | - Flávia Stal Papini
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Hartmannstr. 14, 91052, Erlangen, Germany
| | - David Dulin
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Hartmannstr. 14, 91052, Erlangen, Germany.
| |
Collapse
|
36
|
Malik O, Khamis H, Rudnizky S, Kaplan A. The mechano-chemistry of a monomeric reverse transcriptase. Nucleic Acids Res 2018; 45:12954-12962. [PMID: 29165701 PMCID: PMC5728418 DOI: 10.1093/nar/gkx1168] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/08/2017] [Indexed: 01/28/2023] Open
Abstract
Retroviral reverse transcriptase catalyses the synthesis of an integration-competent dsDNA molecule, using as a substrate the viral RNA. Using optical tweezers, we follow the Murine Leukemia Virus reverse transcriptase as it performs strand-displacement polymerization on a template under mechanical force. Our results indicate that reverse transcriptase functions as a Brownian ratchet, with dNTP binding as the rectifying reaction of the ratchet. We also found that reverse transcriptase is a relatively passive enzyme, able to polymerize on structured templates by exploiting their thermal breathing. Finally, our results indicate that the enzyme enters the recently characterized backtracking state from the pre-translocation complex.
Collapse
Affiliation(s)
- Omri Malik
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Hadeel Khamis
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Faculty of Physics, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Sergei Rudnizky
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Ariel Kaplan
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| |
Collapse
|
37
|
Malik O, Khamis H, Rudnizky S, Marx A, Kaplan A. Pausing kinetics dominates strand-displacement polymerization by reverse transcriptase. Nucleic Acids Res 2017; 45:10190-10205. [PMID: 28973474 PMCID: PMC5737391 DOI: 10.1093/nar/gkx720] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 08/08/2017] [Indexed: 12/20/2022] Open
Abstract
Reverse transcriptase (RT) catalyzes the conversion of the viral RNA into an integration-competent double-stranded DNA, with a variety of enzymatic activities that include the ability to displace a non-template strand concomitantly with polymerization. Here, using high-resolution optical tweezers to follow the activity of the murine leukemia Virus RT, we show that strand-displacement polymerization is frequently interrupted. Abundant pauses are modulated by the strength of the DNA duplex ∼8 bp ahead, indicating the existence of uncharacterized RT/DNA interactions, and correspond to backtracking of the enzyme, whose recovery is also modulated by the duplex strength. Dissociation and reinitiation events, which induce long periods of inactivity and are likely the rate-limiting step in the synthesis of the genome in vivo, are modulated by the template structure and the viral nucleocapsid protein. Our results emphasize the potential regulatory role of conserved structural motifs, and may provide useful information for the development of potent and specific inhibitors.
Collapse
Affiliation(s)
- Omri Malik
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Hadeel Khamis
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Faculty of Physics, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Sergei Rudnizky
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Ailie Marx
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Ariel Kaplan
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| |
Collapse
|
38
|
Le TT, Furukohri A, Tatsumi-Akiyama M, Maki H. Collision with duplex DNA renders Escherichia coli DNA polymerase III holoenzyme susceptible to DNA polymerase IV-mediated polymerase switching on the sliding clamp. Sci Rep 2017; 7:12755. [PMID: 29038530 PMCID: PMC5643309 DOI: 10.1038/s41598-017-13080-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 09/18/2017] [Indexed: 11/12/2022] Open
Abstract
Organisms possess multiple DNA polymerases (Pols) and use each for a different purpose. One of the five Pols in Escherichia coli, DNA polymerase IV (Pol IV), encoded by the dinB gene, is known to participate in lesion bypass at certain DNA adducts. To understand how cells choose Pols when the replication fork encounters an obstacle on template DNA, the process of polymerase exchange from the primary replicative enzyme DNA polymerase III (Pol III) to Pol IV was studied in vitro. Replicating Pol III forming a tight holoenzyme (Pol III HE) with the sliding clamp was challenged by Pol IV on a primed ssDNA template carrying a short inverted repeat. A rapid and lesion-independent switch from Pol III to Pol IV occurred when Pol III HE encountered a hairpin stem duplex, implying that the loss of Pol III-ssDNA contact induces switching to Pol IV. Supporting this idea, mutant Pol III with an increased affinity for ssDNA was more resistant to Pol IV than wild-type Pol III was. We observed that an exchange between Pol III and Pol IV also occurred when Pol III HE collided with primer/template duplex. Our data suggest that Pol III-ssDNA interaction may modulate the susceptibility of Pol III HE to Pol IV-mediated polymerase exchange.
Collapse
Affiliation(s)
- Thanh Thi Le
- Division of Systems Biology, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan
| | - Asako Furukohri
- Division of Systems Biology, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan.
| | - Masahiro Tatsumi-Akiyama
- Division of Systems Biology, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan
| | - Hisaji Maki
- Division of Systems Biology, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan
| |
Collapse
|
39
|
Benkovic SJ, Spiering MM. Understanding DNA replication by the bacteriophage T4 replisome. J Biol Chem 2017; 292:18434-18442. [PMID: 28972188 DOI: 10.1074/jbc.r117.811208] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The T4 replisome has provided a unique opportunity to investigate the intricacies of DNA replication. We present a comprehensive review of this system focusing on the following: its 8-protein composition, their individual and synergistic activities, and assembly in vitro and in vivo into a replisome capable of coordinated leading/lagging strand DNA synthesis. We conclude with a brief comparison with other replisomes with emphasis on how coordinated DNA replication is achieved.
Collapse
Affiliation(s)
- Stephen J Benkovic
- From the Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Michelle M Spiering
- From the Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802
| |
Collapse
|
40
|
A DNA-centered explanation of the DNA polymerase translocation mechanism. Sci Rep 2017; 7:7566. [PMID: 28790383 PMCID: PMC5548866 DOI: 10.1038/s41598-017-08038-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 07/05/2017] [Indexed: 11/08/2022] Open
Abstract
DNA polymerase couples chemical energy to translocation along a DNA template with a specific directionality while it replicates genetic information. According to single-molecule manipulation experiments, the polymerase-DNA complex can work against loads greater than 50 pN. It is not known, on the one hand, how chemical energy is transduced into mechanical motion, accounting for such large forces on sub-nanometer steps, and, on the other hand, how energy consumption in fidelity maintenance integrates in this non-equilibrium cycle. Here, we propose a translocation mechanism that points to the flexibility of the DNA, including its overstretching transition, as the principal responsible for the DNA polymerase ratcheting motion. By using thermodynamic analyses, we then find that an external load hardly affects the fidelity of the copying process and, consequently, that translocation and fidelity maintenance are loosely coupled processes. The proposed translocation mechanism is compatible with single-molecule experiments, structural data and stereochemical details of the DNA-protein complex that is formed during replication, and may be extended to RNA transcription.
Collapse
|
41
|
Hoekstra TP, Depken M, Lin SN, Cabanas-Danés J, Gross P, Dame RT, Peterman EJG, Wuite GJL. Switching between Exonucleolysis and Replication by T7 DNA Polymerase Ensures High Fidelity. Biophys J 2017; 112:575-583. [PMID: 28256218 DOI: 10.1016/j.bpj.2016.12.044] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 12/02/2016] [Accepted: 12/27/2016] [Indexed: 12/11/2022] Open
Abstract
DNA polymerase catalyzes the accurate transfer of genetic information from one generation to the next, and thus it is vitally important for replication to be faithful. DNA polymerase fulfills the strict requirements for fidelity by a combination of mechanisms: 1) high selectivity for correct nucleotide incorporation, 2) a slowing down of the replication rate after misincorporation, and 3) proofreading by excision of misincorporated bases. To elucidate the kinetic interplay between replication and proofreading, we used high-resolution optical tweezers to probe how DNA-duplex stability affects replication by bacteriophage T7 DNA polymerase. Our data show highly irregular replication dynamics, with frequent pauses and direction reversals as the polymerase cycles through the states that govern the mechanochemistry behind high-fidelity T7 DNA replication. We constructed a kinetic model that incorporates both existing biochemical data and the, to our knowledge, novel states we observed. We fit the model directly to the acquired pause-time and run-time distributions. Our findings indicate that the main pathway for error correction is DNA polymerase dissociation-mediated DNA transfer, followed by biased binding into the exonuclease active site. The number of bases removed by this proofreading mechanism is much larger than the number of erroneous bases that would be expected to be incorporated, ensuring a high-fidelity replication of the bacteriophage T7 genome.
Collapse
Affiliation(s)
- Tjalle P Hoekstra
- Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, the Netherlands; LaserLaB Amsterdam, Vrije Universiteit, Amsterdam, the Netherlands
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Szu-Ning Lin
- Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, the Netherlands; LaserLaB Amsterdam, Vrije Universiteit, Amsterdam, the Netherlands; Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Jordi Cabanas-Danés
- Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, the Netherlands; LaserLaB Amsterdam, Vrije Universiteit, Amsterdam, the Netherlands
| | - Peter Gross
- Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, the Netherlands; LaserLaB Amsterdam, Vrije Universiteit, Amsterdam, the Netherlands
| | - Remus T Dame
- Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Erwin J G Peterman
- Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, the Netherlands; LaserLaB Amsterdam, Vrije Universiteit, Amsterdam, the Netherlands
| | - Gijs J L Wuite
- Department of Physics and Astronomy, Vrije Universiteit, Amsterdam, the Netherlands; LaserLaB Amsterdam, Vrije Universiteit, Amsterdam, the Netherlands.
| |
Collapse
|
42
|
Hodeib S, Raj S, Manosas M, Zhang W, Bagchi D, Ducos B, Fiorini F, Kanaan J, Le Hir H, Allemand J, Bensimon D, Croquette V. A mechanistic study of helicases with magnetic traps. Protein Sci 2017; 26:1314-1336. [PMID: 28474797 PMCID: PMC5477542 DOI: 10.1002/pro.3187] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 04/29/2017] [Accepted: 05/02/2017] [Indexed: 01/08/2023]
Abstract
Helicases are a broad family of enzymes that separate nucleic acid double strand structures (DNA/DNA, DNA/RNA, or RNA/RNA) and thus are essential to DNA replication and the maintenance of nucleic acid integrity. We review the picture that has emerged from single molecule studies of the mechanisms of DNA and RNA helicases and their interactions with other proteins. Many features have been uncovered by these studies that were obscured by bulk studies, such as DNA strands switching, mechanical (rather than biochemical) coupling between helicases and polymerases, helicase-induced re-hybridization and stalled fork rescue.
Collapse
Affiliation(s)
- Samar Hodeib
- Laboratoire de physique statistiqueDépartement de physique de l'ENS, École normale supérieure, PSL Research University, Université Paris Diderot, Sorbonne Paris Cité, Sorbonne Universités, UPMC Univ. Paris 06, CNRS75005ParisFrance
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS)Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University75005ParisFrance
| | - Saurabh Raj
- Laboratoire de physique statistiqueDépartement de physique de l'ENS, École normale supérieure, PSL Research University, Université Paris Diderot, Sorbonne Paris Cité, Sorbonne Universités, UPMC Univ. Paris 06, CNRS75005ParisFrance
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS)Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University75005ParisFrance
| | - Maria Manosas
- Departament de Física FonamentalFacultat de Física, Universitat de BarcelonaBarcelona08028Spain
- CIBER‐BBN de BioingenieriaBiomateriales y Nanomedicina, Instituto de Sanidad Carlos IIIMadridSpain
| | - Weiting Zhang
- Laboratoire de physique statistiqueDépartement de physique de l'ENS, École normale supérieure, PSL Research University, Université Paris Diderot, Sorbonne Paris Cité, Sorbonne Universités, UPMC Univ. Paris 06, CNRS75005ParisFrance
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS)Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University75005ParisFrance
| | - Debjani Bagchi
- Laboratoire de physique statistiqueDépartement de physique de l'ENS, École normale supérieure, PSL Research University, Université Paris Diderot, Sorbonne Paris Cité, Sorbonne Universités, UPMC Univ. Paris 06, CNRS75005ParisFrance
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS)Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University75005ParisFrance
- Present address: Physics DepartmentFaculty of Science, The M.S. University of BarodaVadodaraGujarat390002India
| | - Bertrand Ducos
- Laboratoire de physique statistiqueDépartement de physique de l'ENS, École normale supérieure, PSL Research University, Université Paris Diderot, Sorbonne Paris Cité, Sorbonne Universités, UPMC Univ. Paris 06, CNRS75005ParisFrance
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS)Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University75005ParisFrance
| | - Francesca Fiorini
- Univ Lyon, Molecular Microbiology and Structural Biochemistry, MMSB‐IBCP UMR5086 CNRS/Lyon1Lyon Cedex 769367France
| | - Joanne Kanaan
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS)Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University75005ParisFrance
| | - Hervé Le Hir
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS)Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University75005ParisFrance
| | - Jean‐François Allemand
- Laboratoire de physique statistiqueDépartement de physique de l'ENS, École normale supérieure, PSL Research University, Université Paris Diderot, Sorbonne Paris Cité, Sorbonne Universités, UPMC Univ. Paris 06, CNRS75005ParisFrance
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS)Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University75005ParisFrance
| | - David Bensimon
- Laboratoire de physique statistiqueDépartement de physique de l'ENS, École normale supérieure, PSL Research University, Université Paris Diderot, Sorbonne Paris Cité, Sorbonne Universités, UPMC Univ. Paris 06, CNRS75005ParisFrance
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS)Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University75005ParisFrance
- Department of Chemistry and BiochemistryUniversity of California Los AngelesLos AngelesCalifornia90095
| | - Vincent Croquette
- Laboratoire de physique statistiqueDépartement de physique de l'ENS, École normale supérieure, PSL Research University, Université Paris Diderot, Sorbonne Paris Cité, Sorbonne Universités, UPMC Univ. Paris 06, CNRS75005ParisFrance
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS)Département de biologie, École normale supérieure, CNRS, INSERM, PSL Research University75005ParisFrance
| |
Collapse
|
43
|
Dulin D, Cui TJ, Cnossen J, Docter MW, Lipfert J, Dekker NH. High Spatiotemporal-Resolution Magnetic Tweezers: Calibration and Applications for DNA Dynamics. Biophys J 2016; 109:2113-25. [PMID: 26588570 DOI: 10.1016/j.bpj.2015.10.018] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 10/05/2015] [Accepted: 10/13/2015] [Indexed: 11/16/2022] Open
Abstract
The observation of biological processes at the molecular scale in real time requires high spatial and temporal resolution. Magnetic tweezers are straightforward to implement, free of radiation or photodamage, and provide ample multiplexing capability, but their spatiotemporal resolution has lagged behind that of other single-molecule manipulation techniques, notably optical tweezers and AFM. Here, we present, to our knowledge, a new high-resolution magnetic tweezers apparatus. We systematically characterize the achievable spatiotemporal resolution for both incoherent and coherent light sources, different types and sizes of beads, and different types and lengths of tethered molecules. Using a bright coherent laser source for illumination and tracking at 6 kHz, we resolve 3 Å steps with a 1 s period for surface-melted beads and 5 Å steps with a 0.5 s period for double-stranded-dsDNA-tethered beads, in good agreement with a model of stochastic bead motion in the magnetic tweezers. We demonstrate how this instrument can be used to monitor the opening and closing of a DNA hairpin on millisecond timescales in real time, together with attendant changes in the hairpin dynamics upon the addition of deoxythymidine triphosphate. Our approach opens up the possibility of observing biological events at submillisecond timescales with subnanometer resolution using camera-based detection.
Collapse
Affiliation(s)
- David Dulin
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
| | - Tao Ju Cui
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Jelmer Cnossen
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Margreet W Docter
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Jan Lipfert
- Department of Physics, Nanosystems Initiative Munich and Center for Nanoscience, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Nynke H Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
| |
Collapse
|
44
|
Ganai RA, Zhang XP, Heyer WD, Johansson E. Strand displacement synthesis by yeast DNA polymerase ε. Nucleic Acids Res 2016; 44:8229-40. [PMID: 27325747 PMCID: PMC5041465 DOI: 10.1093/nar/gkw556] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/09/2016] [Indexed: 11/30/2022] Open
Abstract
DNA polymerase ε (Pol ε) is a replicative DNA polymerase with an associated 3′–5′ exonuclease activity. Here, we explored the capacity of Pol ε to perform strand displacement synthesis, a process that influences many DNA transactions in vivo. We found that Pol ε is unable to carry out extended strand displacement synthesis unless its 3′–5′ exonuclease activity is removed. However, the wild-type Pol ε holoenzyme efficiently displaced one nucleotide when encountering double-stranded DNA after filling a gap or nicked DNA. A flap, mimicking a D-loop or a hairpin structure, on the 5′ end of the blocking primer inhibited Pol ε from synthesizing DNA up to the fork junction. This inhibition was observed for Pol ε but not with Pol δ, RB69 gp43 or Pol η. Neither was Pol ε able to extend a D-loop in reconstitution experiments. Finally, we show that the observed strand displacement synthesis by exonuclease-deficient Pol ε is distributive. Our results suggest that Pol ε is unable to extend the invading strand in D-loops during homologous recombination or to add more than two nucleotides during long-patch base excision repair. Our results support the hypothesis that Pol ε participates in short-patch base excision repair and ribonucleotide excision repair.
Collapse
Affiliation(s)
- Rais A Ganai
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden Howard Hughes Medical Institute, Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, NY 10016, USA
| | - Xiao-Ping Zhang
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616-8665, USA
| | - Wolf-Dietrich Heyer
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616-8665, USA
| | - Erik Johansson
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
| |
Collapse
|
45
|
Resolving individual steps of Okazaki-fragment maturation at a millisecond timescale. Nat Struct Mol Biol 2016; 23:402-8. [PMID: 27065195 PMCID: PMC4857878 DOI: 10.1038/nsmb.3207] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/18/2016] [Indexed: 11/08/2022]
Abstract
DNA polymerase delta (Pol δ) is responsible for elongation and maturation of Okazaki fragments. Pol δ and the flap endonuclease FEN1, coordinated by the PCNA clamp, remove RNA primers and produce ligatable nicks. We studied this process in the Saccharomyces cerevisiae machinery at millisecond resolution. During elongation, PCNA increased the Pol δ catalytic rate by >30-fold. When Pol δ invaded double-stranded RNA-DNA representing unmatured Okazaki fragments, the incorporation rate of each nucleotide decreased successively to 10-20% that of the preceding nucleotide. Thus, the nascent flap acts as a progressive molecular brake on the polymerase, and consequently FEN1 cuts predominantly single-nucleotide flaps. Kinetic and enzyme-trapping experiments support a model in which a stable PCNA-DNA-Pol δ-FEN1 complex moves processively through iterative steps of nick translation, ultimately completely removing primer RNA. Finally, whereas elongation rates are under dynamic dNTP control, maturation rates are buffered against changes in dNTP concentrations.
Collapse
|
46
|
Abstract
The machines that decode and regulate genetic information require the translation, transcription and replication pathways essential to all living cells. Thus, it might be expected that all cells share the same basic machinery for these pathways that were inherited from the primordial ancestor cell from which they evolved. A clear example of this is found in the translation machinery that converts RNA sequence to protein. The translation process requires numerous structural and catalytic RNAs and proteins, the central factors of which are homologous in all three domains of life, bacteria, archaea and eukarya. Likewise, the central actor in transcription, RNA polymerase, shows homology among the catalytic subunits in bacteria, archaea and eukarya. In contrast, while some "gears" of the genome replication machinery are homologous in all domains of life, most components of the replication machine appear to be unrelated between bacteria and those of archaea and eukarya. This review will compare and contrast the central proteins of the "replisome" machines that duplicate DNA in bacteria, archaea and eukarya, with an eye to understanding the issues surrounding the evolution of the DNA replication apparatus.
Collapse
Affiliation(s)
- Nina Y Yao
- a DNA Replication Laboratory, The Rockefeller University , New York , NY , USA and
| | - Mike E O'Donnell
- a DNA Replication Laboratory, The Rockefeller University , New York , NY , USA and.,b Howard Hughes Medical Institute, The Rockefeller University , New York , NY , USA
| |
Collapse
|
47
|
Sun B, Pandey M, Inman JT, Yang Y, Kashlev M, Patel SS, Wang MD. T7 replisome directly overcomes DNA damage. Nat Commun 2015; 6:10260. [PMID: 26675048 PMCID: PMC4703881 DOI: 10.1038/ncomms10260] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/22/2015] [Indexed: 11/09/2022] Open
Abstract
Cells and viruses possess several known ‘restart' pathways to overcome lesions during DNA replication. However, these ‘bypass' pathways leave a gap in replicated DNA or require recruitment of accessory proteins, resulting in significant delays to fork movement or even cell division arrest. Using single-molecule and ensemble methods, we demonstrate that the bacteriophage T7 replisome is able to directly replicate through a leading-strand cyclobutane pyrimidine dimer (CPD) lesion. We show that when a replisome encounters the lesion, a substantial fraction of DNA polymerase (DNAP) and helicase stay together at the lesion, the replisome does not dissociate and the helicase does not move forward on its own. The DNAP is able to directly replicate through the lesion by working in conjunction with helicase through specific helicase–DNAP interactions. These observations suggest that the T7 replisome is fundamentally permissive of DNA lesions via pathways that do not require fork adjustment or replisome reassembly. Genomic instability can result from stalled or collapsed replication fork at sites of unrepaired DNA lesions. Here the authors uncover a new lesion bypass pathway for the T7 replisome, where leading strand template lesions can be overcome through interaction between the replisome's helicase and polymerase components.
Collapse
Affiliation(s)
- Bo Sun
- Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.,Howard Hughes Medical Institute, Cornell University, Ithaca, New York 14853, USA.,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Manjula Pandey
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
| | - James T Inman
- Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.,Howard Hughes Medical Institute, Cornell University, Ithaca, New York 14853, USA
| | - Yi Yang
- Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.,Howard Hughes Medical Institute, Cornell University, Ithaca, New York 14853, USA
| | - Mikhail Kashlev
- NCI Center for Cancer Research, Frederick, Maryland 21702, USA
| | - Smita S Patel
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
| | - Michelle D Wang
- Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.,Howard Hughes Medical Institute, Cornell University, Ithaca, New York 14853, USA
| |
Collapse
|
48
|
Untangling reaction pathways through modern approaches to high-throughput single-molecule force-spectroscopy experiments. Curr Opin Struct Biol 2015; 34:116-22. [PMID: 26434413 DOI: 10.1016/j.sbi.2015.08.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 08/06/2015] [Accepted: 08/10/2015] [Indexed: 11/22/2022]
Abstract
Single-molecule experiments provide a unique means for real-time observation of the activity of individual biomolecular machines. Through such techniques, insights into the mechanics of for example, polymerases, helicases, and packaging motors have been gleaned. Here we describe the recent advances in single-molecule force spectroscopy instrumentation that have facilitated high-throughput acquisition at high spatiotemporal resolution. The large datasets attained by such methods can capture rare but important events, and contain information regarding stochastic behaviors covering many orders of magnitude in time. We further discuss analysis of such data sets, and with a special focus on the pause states described in the general literature on RNA polymerase pausing we compare and contrast the signatures of different reaction pathways.
Collapse
|
49
|
Yang Z, Price NE, Johnson KM, Gates KS. Characterization of Interstrand DNA-DNA Cross-Links Derived from Abasic Sites Using Bacteriophage ϕ29 DNA Polymerase. Biochemistry 2015; 54:4259-66. [PMID: 26103998 PMCID: PMC4826736 DOI: 10.1021/acs.biochem.5b00482] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Interstrand cross-links in cellular DNA are highly deleterious lesions that block transcription and replication. We recently characterized two new structural types of interstrand cross-links derived from the reaction of abasic (Ap) sites with either guanine or adenine residues in duplex DNA. Interestingly, these Ap-derived cross-links are forged by chemically reversible processes, in which the two strands of the duplex are joined by hemiaminal, imine, or aminoglycoside linkages. Therefore, understanding the stability of Ap-derived cross-links may be critical in defining the potential biological consequences of these lesions. Here we employed bacteriophage φ29 DNA polymerase, which can couple DNA synthesis and strand displacement, as a model system to examine whether dA-Ap cross-links can withstand DNA-processing enzymes. We first demonstrated that a chemically stable interstrand cross-link generated by hydride reduction of the dG-Ap cross-link completely blocked primer extension by φ29 DNA polymerase at the last unmodified nucleobase preceding cross-link. We then showed that the nominally reversible dA-Ap cross-link behaved, for all practical purposes, like an irreversible, covalent DNA-DNA cross-link. The dA-Ap cross-link completely blocked progress of the φ29 DNA polymerase at the last unmodified base before the cross-link. This suggests that Ap-derived cross-links have the power to block various DNA-processing enzymes in the cell. In addition, our results reveal φ29 DNA polymerase as a tool for detecting the presence and mapping the location of interstrand cross-links (and possibly other lesions) embedded within regions of duplex DNA.
Collapse
Affiliation(s)
- Zhiyu Yang
- Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211
| | - Nathan E. Price
- Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211
| | - Kevin M. Johnson
- Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211
| | - Kent S. Gates
- Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211
- Department of Biochemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211
| |
Collapse
|
50
|
Nandakumar D, Pandey M, Patel SS. Cooperative base pair melting by helicase and polymerase positioned one nucleotide from each other. eLife 2015; 4. [PMID: 25970034 PMCID: PMC4460406 DOI: 10.7554/elife.06562] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 05/13/2015] [Indexed: 12/19/2022] Open
Abstract
Leading strand DNA synthesis requires functional coupling between replicative helicase and DNA polymerase (DNAP) enzymes, but the structural and mechanistic basis of coupling is poorly understood. This study defines the precise positions of T7 helicase and T7 DNAP at the replication fork junction with single-base resolution to create a structural model that explains the mutual stimulation of activities. Our 2-aminopurine studies show that helicase and polymerase both participate in DNA melting, but each enzyme melts the junction base pair partially. When combined, the junction base pair is melted cooperatively provided the helicase is located one nucleotide ahead of the primer-end. The synergistic shift in equilibrium of junction base pair melting by combined enzymes explains the cooperativity, wherein helicase stimulates the polymerase by promoting dNTP binding (decreasing dNTP Km), polymerase stimulates the helicase by increasing the unwinding rate-constant (kcat), consequently the combined enzymes unwind DNA with kinetic parameters resembling enzymes translocating on single-stranded DNA. DOI:http://dx.doi.org/10.7554/eLife.06562.001 DNA replication is the process whereby a molecule of DNA is copied to form two identical molecules. First, an enzyme called a DNA helicase separates the two strands of the DNA double helix. This forms a structure called a replication fork that has two exposed single strands. Other enzymes called DNA polymerases then use each strand as a template to build a new matching DNA strand. DNA polymerases build the new DNA strands by joining together smaller molecules called nucleotides. One of the new DNA strands—called the ‘leading strand’—is built continuously, while the other—the ‘lagging strand’—is made as a series of short fragments that are later joined together. Building the leading strand requires the helicase and DNA polymerase to work closely together. However, it was not clear how these two enzymes coordinate their activity. Now, Nandakumar et al. have studied the helicase and DNA polymerase from a virus that infects bacteria and have pinpointed the exact positions of the enzymes at a replication fork. The experiments revealed that both the polymerase and helicase contribute to the separating of the DNA strands, and that this process is most efficient when the helicase is only a single nucleotide ahead of the polymerase. Further experiments showed that the helicase stimulates the polymerase by helping it to bind to nucleotides, and that the polymerase stimulates the helicase by helping it to separate the DNA strands at a faster rate. The next challenge is to investigate the molecular setup that allows the helicase and polymerase to increase each other's activities. DOI:http://dx.doi.org/10.7554/eLife.06562.002
Collapse
Affiliation(s)
- Divya Nandakumar
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, United States
| | - Manjula Pandey
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, United States
| | - Smita S Patel
- Department of Biochemistry and Molecular Biology, Rutgers-Robert Wood Johnson Medical School, Piscataway, United States
| |
Collapse
|