1
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Kim S, Shin WH, Kang Y, Kim H, Lee JY. Direct visualization of replication and R-loop collision using single-molecule imaging. Nucleic Acids Res 2024; 52:259-273. [PMID: 37994723 PMCID: PMC10783495 DOI: 10.1093/nar/gkad1101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/12/2023] [Accepted: 11/06/2023] [Indexed: 11/24/2023] Open
Abstract
R-loops are three-stranded nucleic acid structures that can cause replication stress by blocking replication fork progression. However, the detailed mechanism underlying the collision of DNA replication forks and R-loops remains elusive. To investigate how R-loops induce replication stress, we use single-molecule fluorescence imaging to directly visualize the collision of replicating Phi29 DNA polymerase (Phi29 DNAp), the simplest replication system, and R-loops. We demonstrate that a single R-loop can block replication, and the blockage is more pronounced when an RNA-DNA hybrid is on the non-template strand. We show that this asymmetry results from secondary structure formation on the non-template strand, which impedes the progression of Phi29 DNAp. We also show that G-quadruplex formation on the displaced single-stranded DNA in an R-loop enhances the replication stalling. Moreover, we observe the collision between Phi29 DNAp and RNA transcripts synthesized by T7 RNA polymerase (T7 RNAp). RNA transcripts cause more stalling because of the presence of T7 RNAp. Our work provides insights into how R-loops impede DNA replication at single-molecule resolution.
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Affiliation(s)
- Subin Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Woo Hee Shin
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Yujin Kang
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Hongtae Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Ja Yil Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
- Institute of Basic Science Center for Genomic Integrity, Ulsan 44919, Republic of Korea
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2
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Pflug FG, Bhat D, Pigolotti S. Genome replication in asynchronously growing microbial populations. PLoS Comput Biol 2024; 20:e1011753. [PMID: 38181054 PMCID: PMC10796026 DOI: 10.1371/journal.pcbi.1011753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/18/2024] [Accepted: 12/11/2023] [Indexed: 01/07/2024] Open
Abstract
Biological cells replicate their genomes in a well-planned manner. The DNA replication program of an organism determines the timing at which different genomic regions are replicated, with fundamental consequences for cell homeostasis and genome stability. In a growing cell culture, genomic regions that are replicated early should be more abundant than regions that are replicated late. This abundance pattern can be experimentally measured using deep sequencing. However, a general quantitative theory linking this pattern to the replication program is still lacking. In this paper, we predict the abundance of DNA fragments in asynchronously growing cultures from any given stochastic model of the DNA replication program. As key examples, we present stochastic models of the DNA replication programs in budding yeast and Escherichia coli. In both cases, our model results are in excellent agreement with experimental data and permit to infer key information about the replication program. In particular, our method is able to infer the locations of known replication origins in budding yeast with high accuracy. These examples demonstrate that our method can provide insight into a broad range of organisms, from bacteria to eukaryotes.
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Affiliation(s)
- Florian G. Pflug
- Biological Complexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, Japan
| | - Deepak Bhat
- Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - Simone Pigolotti
- Biological Complexity Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, Japan
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3
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Schneider L, Richter M, Oelschlaeger C, Rabe KS, Domínguez CM, Niemeyer CM. Accurate quantification of DNA content in DNA hydrogels prepared by rolling circle amplification. Chem Commun (Camb) 2023; 59:12184-12187. [PMID: 37750315 DOI: 10.1039/d3cc04374f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Accurate quantification of polymerized DNA in rolling circle amplification (RCA)-based hydrogels is challenging due to the high viscosity of these materials, however, it can be achieved with a photometric nucleotide depletion assay or qPCR. We show that the DNA content strongly depends on the template sequence and correlates with the mechanical properties of the hydrogels.
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Affiliation(s)
- Leonie Schneider
- Institute of Biological Interfaces (IBG-1), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Madleen Richter
- Institute of Biological Interfaces (IBG-1), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Claude Oelschlaeger
- Institute for Mechanical Process Engineering and Mechanics, Karlsruhe Institute of Technology (KIT), Gotthard-Franz-Straße 3, 76131 Karlsruhe, Germany
| | - Kersten S Rabe
- Institute of Biological Interfaces (IBG-1), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Carmen M Domínguez
- Institute of Biological Interfaces (IBG-1), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Christof M Niemeyer
- Institute of Biological Interfaces (IBG-1), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
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4
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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.
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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
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5
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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.
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6
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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.
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7
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Shen C, Qin CR, Xu TL, Chen K, Tian WD. Structure and dynamics of an active polymer adsorbed on the surface of a cylinder. SOFT MATTER 2022; 18:1489-1497. [PMID: 35089305 DOI: 10.1039/d1sm01658j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The structure and dynamics of an active polymer on a smooth cylindrical surface are studied by Brownian dynamics simulations. The effect of an active force on the polymer adsorption behavior and the combined effect of chain mobility, length N, rigidity κ, and cylinder radius, R, on the phase diagrams are systemically investigated. We find that complete adsorption is replaced by the irregular alternative adsorption/desorption process at a large driving force. Three typical (spiral, helix-like, and rod-like) conformations of the active polymer are observed, dependent on N, κ, and R. Dynamically, the polymer shows rotational motion in the spiral state, snake-like motion in the intermediate state, and straight translational motion without turning back in the rod-like state. In the spiral state, we find that the rotation velocity ω and the chain length follow a power-law relation ω ∼ N-0.42, consistent with the torque-balance theory of general Archimedean spirals. And the polymer shows super-diffusive behavior along the cylinder for a long time in the helix-like and rod-like states. Our results highlight that the mobility, rigidity, and curvature of surface can be used to regulate the polymer behavior.
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Affiliation(s)
- Chen Shen
- Center for Soft Condensed Matter Physics & Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, China.
| | - Chao-Ran Qin
- Center for Soft Condensed Matter Physics & Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, China.
| | - Tian-Liang Xu
- Center for Soft Condensed Matter Physics & Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, China.
| | - Kang Chen
- Center for Soft Condensed Matter Physics & Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, China.
| | - Wen-de Tian
- Center for Soft Condensed Matter Physics & Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, China.
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8
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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.
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9
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Li J, Yu N, Li X, Cui M, Guo Q. The Single-Cell Sequencing: A Dazzling Light Shining on the Dark Corner of Cancer. Front Oncol 2021; 11:759894. [PMID: 34745998 PMCID: PMC8566994 DOI: 10.3389/fonc.2021.759894] [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: 08/17/2021] [Accepted: 09/30/2021] [Indexed: 11/30/2022] Open
Abstract
Tumorigenesis refers to the process of clonal dysplasia that occurs due to the collapse of normal growth regulation in cells caused by the action of various carcinogenic factors. These “successful” tumor cells pass on the genetic templates to their generations in evolutionary terms, but they also constantly adapt to ever-changing host environments. A unique peculiarity known as intratumor heterogeneity (ITH) is extensively involved in tumor development, metastasis, chemoresistance, and immune escape. An understanding of ITH is urgently required to identify the diversity and complexity of the tumor microenvironment (TME), but achieving this understanding has been a challenge. Single-cell sequencing (SCS) is a powerful tool that can gauge the distribution of genomic sequences in a single cell and the genetic variability among tumor cells, which can improve the understanding of ITH. SCS provides fundamental ideas about existing diversity in specific TMEs, thus improving cancer diagnosis and prognosis prediction, as well as improving the monitoring of therapeutic response. Herein, we will discuss advances in SCS and review SCS application in tumors based on current evidence.
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Affiliation(s)
- Jing Li
- Department of Clinical Pharmacy, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Nan Yu
- Department of Pharmacy, Qingdao Eighth People's Hospital, Qingdao, China
| | - Xin Li
- Department of Clinical Pharmacy, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Mengna Cui
- Department of Clinical Pharmacy, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Qie Guo
- Department of Clinical Pharmacy, The Affiliated Hospital of Qingdao University, Qingdao, China
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10
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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.
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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.
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11
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Housh K, Jha JS, Yang Z, Haldar T, Johnson KM, Yin J, Wang Y, Gates KS. Formation and Repair of an Interstrand DNA Cross-Link Arising from a Common Endogenous Lesion. J Am Chem Soc 2021; 143:15344-15357. [PMID: 34516735 DOI: 10.1021/jacs.1c06926] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Interstrand DNA cross-links (ICLs) are cytotoxic because they block the strand separation required for read-out and replication of the genetic information in duplex DNA. The unavoidable formation of ICLs in cellular DNA may contribute to aging, neurodegeneration, and cancer. Here, we describe the formation and properties of a structurally complex ICL derived from an apurinic/apyrimidinic (AP) site, which is one of the most common endogenous lesions in cellular DNA. The results characterize a cross-link arising from aza-Michael addition of the N2-amino group of a guanine residue to the electrophilic sugar remnant generated by spermine-mediated strand cleavage at an AP site in duplex DNA. An α,β-unsaturated iminium ion is the critical intermediate involved in ICL formation. Studies employing the bacteriophage φ29 polymerase provided evidence that this ICL can block critical DNA transactions that require strand separation. The results of biochemical studies suggest that this complex strand break/ICL might be repaired by a simple mechanism in which the 3'-exonuclease action of the enzyme apurinic/apyrimidinic endonuclease (APE1) unhooks the cross-link to initiate repair via the single-strand break repair pathway.
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Affiliation(s)
- Kurt Housh
- University of Missouri Department of Chemistry 125 Chemistry Building Columbia, Missouri 65211, United States
| | - Jay S Jha
- University of Missouri Department of Chemistry 125 Chemistry Building Columbia, Missouri 65211, United States
| | - Zhiyu Yang
- University of Missouri Department of Chemistry 125 Chemistry Building Columbia, Missouri 65211, United States
| | - Tuhin Haldar
- University of Missouri Department of Chemistry 125 Chemistry Building Columbia, Missouri 65211, United States
| | - Kevin M Johnson
- University of Missouri Department of Chemistry 125 Chemistry Building Columbia, Missouri 65211, United States
| | - Jiekai Yin
- Department of Chemistry University of California-Riverside Riverside, California 92521-0403, United States
| | - Yinsheng Wang
- Department of Chemistry University of California-Riverside Riverside, California 92521-0403, United States
| | - Kent S Gates
- University of Missouri Department of Chemistry 125 Chemistry Building Columbia, Missouri 65211, United States.,University of Missouri Department of Biochemistry 125 Chemistry Building Columbia, Missouri 65211, United States
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12
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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.
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Affiliation(s)
| | - Yang Gao
- Correspondence: ; Tel.: +1-713-348-2619
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13
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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.
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14
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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.
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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
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15
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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.
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16
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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.
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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
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17
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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.
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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
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18
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Zhang S, Zhang Q, Hou X, Guo L, Wang F, Bi L, Zhang X, Li H, Wen F, Xi X, Huang X, Shen B, Sun B. Dynamics of Staphylococcus aureus Cas9 in DNA target Association and Dissociation. EMBO Rep 2020; 21:e50184. [PMID: 32790142 PMCID: PMC7534634 DOI: 10.15252/embr.202050184] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 07/11/2020] [Accepted: 07/21/2020] [Indexed: 12/29/2022] Open
Abstract
Staphylococcus aureus Cas9 (SaCas9) is an RNA-guided endonuclease that targets complementary DNA adjacent to a protospacer adjacent motif (PAM) for cleavage. Its small size facilitates in vivo delivery for genome editing in various organisms. Herein, using single-molecule and ensemble approaches, we systemically study the mechanism of SaCas9 underlying its interplay with DNA. We find that the DNA binding and cleavage of SaCas9 require complementarities of 6- and 18-bp of PAM-proximal DNA with guide RNA, respectively. These activities are mediated by two steady interactions among the ternary complex, one of which is located approximately 6 bp from the PAM and beyond the apparent footprint of SaCas9 on DNA. Notably, the other interaction within the protospacer is significantly strong and thus poses DNA-bound SaCas9 a persistent block to DNA-tracking motors. Intriguingly, after cleavage, SaCas9 autonomously releases the PAM-distal DNA while retaining binding to the PAM. This partial DNA release immediately abolishes its strong interaction with the protospacer DNA and consequently promotes its subsequent dissociation from the PAM. Overall, these data provide a dynamic understanding of SaCas9 and instruct its effective applications.
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Affiliation(s)
- Siqi Zhang
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
- Shanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Qian Zhang
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
- Shanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Xi‐Miao Hou
- College of Life SciencesNorthwest A&F UniversityYanglingChina
| | - Lijuan Guo
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
- Shanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Fangzhu Wang
- State Key Laboratory of Reproductive MedicineCenter for Global HealthNanjing Medical UniversityNanjingChina
| | - Lulu Bi
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
| | - Xia Zhang
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
| | - Hai‐Hong Li
- College of Life SciencesNorthwest A&F UniversityYanglingChina
| | - Fengcai Wen
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
- Shanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Xu‐Guang Xi
- The LBPAEcole Normale Supérieure Paris‐SaclayCNRSUniversité Paris SaclayGif‐sur-YvetteFrance
| | - Xingxu Huang
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
| | - Bin Shen
- State Key Laboratory of Reproductive MedicineCenter for Global HealthNanjing Medical UniversityNanjingChina
| | - Bo Sun
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
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19
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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.
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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
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20
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Abstract
Single-molecule techniques have been used successfully to visualize real-time enzymatic activities, revealing transient complex properties and heterogeneity of various biological events. Especially, conventional force spectroscopy including optical tweezers and magnetic tweezers has been widely used to monitor change in DNA length by enzymes with high spatiotemporal resolutions of ~ nanometers and ~ milliseconds. However, DNA metabolism results from coordination of a number of components during the processes, requiring efficient monitoring of a complex of proteins catalyzing DNA substrates. In this min-review, we will introduce a simple and multiplexed single-molecule assay to detect DNA substrates catalyzed by enzymes with high-throughput data collection. We conclude with a perspective of possible directions that enhance capability of the assay to reveal complex biological events with higher resolution.
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Affiliation(s)
- Ryanggeun Lee
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Keunsang Yang
- School of Interdisciplinary Bioscience and Bioengineering, POSTECH, Pohang 37673, Korea
| | - Jong-Bong Lee
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
- School of Interdisciplinary Bioscience and Bioengineering, POSTECH, Pohang 37673, Korea
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21
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Mohapatra S, Lin CT, Feng XA, Basu A, Ha T. Single-Molecule Analysis and Engineering of DNA Motors. Chem Rev 2019; 120:36-78. [DOI: 10.1021/acs.chemrev.9b00361] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
| | | | | | | | - Taekjip Ha
- Howard Hughes Medical Institute, Baltimore, Maryland 21205, United States
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22
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Joffroy B, Uca YO, Prešern D, Doye JPK, Schmidt TL. Rolling circle amplification shows a sinusoidal template length-dependent amplification bias. Nucleic Acids Res 2019; 46:538-545. [PMID: 29237070 PMCID: PMC5778537 DOI: 10.1093/nar/gkx1238] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 11/30/2017] [Indexed: 01/29/2023] Open
Abstract
Biophysical properties of DNA such as its longitudinal and torsional persistence length govern many processes and phenomena in biology, DNA nanotechnology and biotechnology. It has, for example, long been known that the circularization efficiency of short DNA fragments shows a periodic pattern where fragments with integer helical turns circularize much more efficiently than those with odd helical half turns due to stronger stacking of duplex ends. Small DNA circles can serve as templates for rolling circle amplification (RCA), which is a common and extremely robust amplification mechanism for nucleic acids. We discovered a strong template length-dependent amplification efficiency bias of RCA with the same periodicity as B-DNA. However, stacking cannot explain the mechanism behind this bias as the presence of the polymerase in the bifurcation fork inhibits base stacking of ends. Instead, coarse-grained molecular dynamics simulations imply that different amplification efficiencies come from a varying fraying probability of the last two downstream base pairs. We conclude that an increased strain-promoted fraying probability can increase the polymerization rate compared to a relaxed template.
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Affiliation(s)
- Bastian Joffroy
- Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, 01062 Dresden, Germany
| | - Yavuz O Uca
- Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, 01062 Dresden, Germany
| | - Domen Prešern
- Physical & Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Jonathan P K Doye
- Physical & Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Thorsten L Schmidt
- Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, 01062 Dresden, Germany.,B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, 01062 Dresden, Germany
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23
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Burnham DR, Kose HB, Hoyle RB, Yardimci H. The mechanism of DNA unwinding by the eukaryotic replicative helicase. Nat Commun 2019; 10:2159. [PMID: 31089141 PMCID: PMC6517413 DOI: 10.1038/s41467-019-09896-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 04/05/2019] [Indexed: 12/18/2022] Open
Abstract
Accurate DNA replication is tightly regulated in eukaryotes to ensure genome stability during cell division and is performed by the multi-protein replisome. At the core an AAA+ hetero-hexameric complex, Mcm2-7, together with GINS and Cdc45 form the active replicative helicase Cdc45/Mcm2-7/GINS (CMG). It is not clear how this replicative ring helicase translocates on, and unwinds, DNA. We measure real-time dynamics of purified recombinant Drosophila melanogaster CMG unwinding DNA with single-molecule magnetic tweezers. Our data demonstrates that CMG exhibits a biased random walk, not the expected unidirectional motion. Through building a kinetic model we find CMG may enter up to three paused states rather than unwinding, and should these be prevented, in vivo fork rates would be recovered in vitro. We propose a mechanism in which CMG couples ATP hydrolysis to unwinding by acting as a lazy Brownian ratchet, thus providing quantitative understanding of the central process in eukaryotic DNA replication.
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Affiliation(s)
- Daniel R Burnham
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Hazal B Kose
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Rebecca B Hoyle
- School of Mathematical Sciences, University of Southampton, Southampton, SO17 1BJ, UK
| | - Hasan Yardimci
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
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24
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Del Prado A, Rodríguez I, Lázaro JM, Moreno-Morcillo M, de Vega M, Salas M. New insights into the coordination between the polymerization and 3'-5' exonuclease activities in ϕ29 DNA polymerase. Sci Rep 2019; 9:923. [PMID: 30696917 PMCID: PMC6351526 DOI: 10.1038/s41598-018-37513-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 12/06/2018] [Indexed: 11/09/2022] Open
Abstract
Bacteriophage ϕ29 DNA polymerase has two activities: DNA polymerization and 3′-5′ exonucleolysis governed by catalytic sites present in two structurally distant domains. These domains must work together to allow the correct replication of the template and to prevent the accumulation of errors in the newly synthesized DNA strand. ϕ29 DNA polymerase is endowed with a high processivity and strand displacement capacity together with a high fidelity. Previous studies of its crystallographic structure suggested possible interactions of residues of the exonuclease domain like the Gln180 with the fingers subdomain, or water mediated and direct hydrogen bond by the polar groups of residues Tyr101 and Thr189 that could stabilize DNA binding. To analyse their functional importance for the exonuclease activity of ϕ29 DNA polymerase we engineered mutations to encode amino acid substitutions. Our results confirm that both residues, Tyr101 and Thr189 are involved in the 3′-5′ exonuclease activity and in binding the dsDNA. In addition, Tyr101 is playing a role in processivity and Thr189 is an important determinant in the fidelity of the DNA polymerase. On the other hand, the biochemical characterization of the mutant derivatives of residue Gln180 showed how the mutations introduced enhanced the 3′-5′ exonuclease activity of the enzyme. A potential structural conformation prone to degrade the substrate is discussed.
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Affiliation(s)
- Alicia Del Prado
- Centro de Biología Molecular "Severo Ochoa," (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049, Madrid, Spain
| | - Irene Rodríguez
- Centro de Biología Molecular "Severo Ochoa," (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049, Madrid, Spain
| | - José María Lázaro
- Centro de Biología Molecular "Severo Ochoa," (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049, Madrid, Spain
| | - María Moreno-Morcillo
- Centro de Biología Molecular "Severo Ochoa," (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049, Madrid, Spain
| | - Miguel de Vega
- Centro de Biología Molecular "Severo Ochoa," (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049, Madrid, Spain
| | - Margarita Salas
- Centro de Biología Molecular "Severo Ochoa," (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid), Universidad Autónoma, Cantoblanco, 28049, Madrid, Spain.
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25
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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.
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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
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26
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Dynamics of individual molecular shuttles under mechanical force. Nat Commun 2018; 9:4512. [PMID: 30375395 PMCID: PMC6207653 DOI: 10.1038/s41467-018-06905-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/02/2018] [Indexed: 11/24/2022] Open
Abstract
Molecular shuttles are the basis of some of the most advanced synthetic molecular machines. In these devices a macrocycle threaded onto a linear component shuttles between different portions of the thread in response to external stimuli. Here, we use optical tweezers to measure the mechanics and dynamics of individual molecular shuttles in aqueous conditions. Using DNA as a handle and as a single molecule reporter, we measure thousands of individual shuttling events and determine the force-dependent kinetic rates of the macrocycle motion and the main parameters governing the energy landscape of the system. Our findings could open avenues for the real-time characterization of synthetic devices at the single molecule level, and provide crucial information for designing molecular machinery able to operate under physiological conditions. Molecular shuttles are bi-stable and stimuli-responsive systems that are considered potential elements for molecular machinery. Here, the authors use optical tweezers to measure the force dependent real-time kinetics of individual molecular shuttles under aqueous conditions.
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27
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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.
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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
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28
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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.
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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
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29
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Okoniewski SR, Uyetake L, Perkins TT. Force-activated DNA substrates for probing individual proteins interacting with single-stranded DNA. Nucleic Acids Res 2017; 45:10775-10782. [PMID: 28977580 PMCID: PMC5737210 DOI: 10.1093/nar/gkx761] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 08/17/2017] [Indexed: 01/15/2023] Open
Abstract
Single-molecule force spectroscopy provides insight into how proteins bind to and move along DNA. Such studies often embed a single-stranded (ss) DNA region within a longer double-stranded (ds) DNA molecule. Yet, producing these substrates remains laborious and inefficient, particularly when using the traditional three-way hybridization. Here, we developed a force-activated substrate that yields an internal 1000 nucleotide (nt) ssDNA region when pulled partially into the overstretching transition (∼65 pN) by engineering a 50%-GC segment to have no adjacent GC base pairs. Once the template was made, these substrates were efficiently prepared by polymerase chain reaction amplification followed by site-specific nicking. We also generated a more complex structure used in high-resolution helicase studies, a DNA hairpin adjacent to 33 nt of ssDNA. The temporally defined generation of individual hairpin substrates in the presence of RecQ helicase and saturating adenine triphosphate let us deduce that RecQ binds to ssDNA via a near diffusion-limited reaction. More broadly, these substrates enable the precise initiation of an important class of protein–DNA interactions.
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Affiliation(s)
- Stephen R Okoniewski
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, CO 80309-0440, USA.,Department of Physics, University of Colorado, Boulder, CO 80309-0440, USA
| | - Lyle Uyetake
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, CO 80309-0440, USA
| | - Thomas T Perkins
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, CO 80309-0440, USA.,Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309-0440, USA
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30
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Yang Z, Price NE, Johnson KM, Wang Y, Gates KS. Interstrand cross-links arising from strand breaks at true abasic sites in duplex DNA. Nucleic Acids Res 2017; 45:6275-6283. [PMID: 28531327 PMCID: PMC5499897 DOI: 10.1093/nar/gkx394] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 05/02/2017] [Indexed: 01/04/2023] Open
Abstract
Interstrand cross-links are exceptionally bioactive DNA lesions. Endogenous generation of interstrand cross-links in genomic DNA may contribute to aging, neurodegeneration, and cancer. Abasic (Ap) sites are common lesions in genomic DNA that readily undergo spontaneous and amine-catalyzed strand cleavage reactions that generate a 2,3-didehydro-2,3-dideoxyribose sugar remnant (3’ddR5p) at the 3’-terminus of the strand break. Interestingly, this strand scission process leaves an electrophilic α,β-unsaturated aldehyde residue embedded within the resulting nicked duplex. Here we present evidence that 3’ddR5p derivatives generated by spermine-catalyzed strand cleavage at Ap sites in duplex DNA can react with adenine residues on the opposing strand to generate a complex lesion consisting of an interstrand cross-link adjacent to a strand break. The cross-link blocks DNA replication by ϕ29 DNA polymerase, a highly processive polymerase enzyme that couples synthesis with strand displacement. This suggests that 3’ddR5p-derived cross-links have the potential to block critical cellular DNA transactions that require strand separation. LC-MS/MS methods developed herein provide powerful tools for studying the occurrence and properties of these cross-links in biochemical and biological systems.
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Affiliation(s)
- Zhiyu Yang
- Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211, USA
| | - Nathan E Price
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Kevin M Johnson
- Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211, USA
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Kent S Gates
- Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211, USA.,Department of Biochemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211, USA
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31
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Morin JA, Cerrón F, Jarillo J, Beltran-Heredia E, Ciesielski GL, Arias-Gonzalez JR, Kaguni LS, Cao FJ, Ibarra B. DNA synthesis determines the binding mode of the human mitochondrial single-stranded DNA-binding protein. Nucleic Acids Res 2017; 45:7237-7248. [PMID: 28486639 PMCID: PMC5499585 DOI: 10.1093/nar/gkx395] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 04/27/2017] [Indexed: 12/02/2022] Open
Abstract
Single-stranded DNA-binding proteins (SSBs) play a key role in genome maintenance, binding and organizing single-stranded DNA (ssDNA) intermediates. Multimeric SSBs, such as the human mitochondrial SSB (HmtSSB), present multiple sites to interact with ssDNA, which has been shown in vitro to enable them to bind a variable number of single-stranded nucleotides depending on the salt and protein concentration. It has long been suggested that different binding modes might be used selectively for different functions. To study this possibility, we used optical tweezers to determine and compare the structure and energetics of long, individual HmtSSB–DNA complexes assembled on preformed ssDNA and on ssDNA generated gradually during ‘in situ’ DNA synthesis. We show that HmtSSB binds to preformed ssDNA in two major modes, depending on salt and protein concentration. However, when protein binding was coupled to strand-displacement DNA synthesis, only one of the two binding modes was observed under all experimental conditions. Our results reveal a key role for the gradual generation of ssDNA in modulating the binding mode of a multimeric SSB protein and consequently, in generating the appropriate nucleoprotein structure for DNA synthetic reactions required for genome maintenance.
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Affiliation(s)
- José A Morin
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, 28049 Madrid, Spain
| | - Fernando Cerrón
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, 28049 Madrid, Spain
| | - Javier Jarillo
- Departamento Física Atómica, Molecular y Nuclear, Universidad Complutense, 28040 Madrid, Spain
| | - Elena Beltran-Heredia
- Departamento Física Atómica, Molecular y Nuclear, Universidad Complutense, 28040 Madrid, Spain
| | - Grzegorz L Ciesielski
- Institute of Biosciences and Medical Technology, University of Tampere, 33520 Tampere, Finland.,Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI 48823, USA
| | - J Ricardo Arias-Gonzalez
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, 28049 Madrid, Spain.,Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia) and CNB-CSIC-IMDEA Nanociencia Associated Unit 'Unidad de Nanobiotecnología', 28049 Madrid, Spain
| | - Laurie S Kaguni
- Institute of Biosciences and Medical Technology, University of Tampere, 33520 Tampere, Finland.,Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI 48823, USA
| | - Francisco J Cao
- Departamento Física Atómica, Molecular y Nuclear, 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) and CNB-CSIC-IMDEA Nanociencia Associated Unit 'Unidad de Nanobiotecnología', 28049 Madrid, Spain
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32
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Naranjo T, Cerrón F, Nieto-Ortega B, Latorre A, Somoza Á, Ibarra B, Pérez EM. Mechanical measurement of hydrogen bonded host-guest systems under non-equilibrium, near-physiological conditions. Chem Sci 2017; 8:6037-6041. [PMID: 28989633 PMCID: PMC5625567 DOI: 10.1039/c7sc03044d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 07/29/2017] [Indexed: 11/26/2022] Open
Abstract
Decades after the birth of supramolecular chemistry, there are many techniques to measure noncovalent interactions, such as hydrogen bonding, under equilibrium conditions. As ensembles of molecules rapidly lose coherence, we cannot extrapolate bulk data to single-molecule events under non-equilibrium conditions, more relevant to the dynamics of biological systems. We present a new method that exploits the high force resolution of optical tweezers to measure at the single molecule level the mechanical strength of a hydrogen bonded host-guest pair out of equilibrium and under near-physiological conditions. We utilize a DNA reporter to unambiguously isolate single binding events. The Hamilton receptor-cyanuric acid host-guest system is used as a test bed. The force required to dissociate the host-guest system is ∼17 pN and increases with the pulling rate as expected for a system under non-equilibrium conditions. Blocking one of the hydrogen bonding sites results in a significant decrease of the force-to-break by 1-2 pN, pointing out the ability of the method to resolve subtle changes in the mechanical strength of the binding due to the individual H-bonding components. We believe the method will prove to be a versatile tool to address important questions in supramolecular chemistry.
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Affiliation(s)
- Teresa Naranjo
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
| | - Fernando Cerrón
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
| | - Belén Nieto-Ortega
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
| | - Alfonso Latorre
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
| | - Álvaro Somoza
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
- Nanobiotecnología (IMDEA-Nanociencia) , Unidad Asociada al Centro Nacional de Biotecnología (CSIC) , 28049 , Madrid , Spain
| | - Borja Ibarra
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
- Nanobiotecnología (IMDEA-Nanociencia) , Unidad Asociada al Centro Nacional de Biotecnología (CSIC) , 28049 , Madrid , Spain
| | - Emilio M Pérez
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
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33
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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.
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34
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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.
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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.
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35
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Selective Whole-Genome Amplification Is a Robust Method That Enables Scalable Whole-Genome Sequencing of Plasmodium vivax from Unprocessed Clinical Samples. mBio 2017; 8:mBio.02257-16. [PMID: 28174312 PMCID: PMC5296604 DOI: 10.1128/mbio.02257-16] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Whole-genome sequencing (WGS) of microbial pathogens from clinical samples is a highly sensitive tool used to gain a deeper understanding of the biology, epidemiology, and drug resistance mechanisms of many infections. However, WGS of organisms which exhibit low densities in their hosts is challenging due to high levels of host genomic DNA (gDNA), which leads to very low coverage of the microbial genome. WGS of Plasmodium vivax, the most widely distributed form of malaria, is especially difficult because of low parasite densities and the lack of an ex vivo culture system. Current techniques used to enrich P. vivax DNA from clinical samples require significant resources or are not consistently effective. Here, we demonstrate that selective whole-genome amplification (SWGA) can enrich P. vivax gDNA from unprocessed human blood samples and dried blood spots for high-quality WGS, allowing genetic characterization of isolates that would otherwise have been prohibitively expensive or impossible to sequence. We achieved an average genome coverage of 24×, with up to 95% of the P. vivax core genome covered by ≥5 reads. The single-nucleotide polymorphism (SNP) characteristics and drug resistance mutations seen were consistent with those of other P. vivax sequences from a similar region in Peru, demonstrating that SWGA produces high-quality sequences for downstream analysis. SWGA is a robust tool that will enable efficient, cost-effective WGS of P. vivax isolates from clinical samples that can be applied to other neglected microbial pathogens. Malaria is a disease caused by Plasmodium parasites that caused 214 million symptomatic cases and 438,000 deaths in 2015. Plasmodium vivax is the most widely distributed species, causing the majority of malaria infections outside sub-Saharan Africa. Whole-genome sequencing (WGS) of Plasmodium parasites from clinical samples has revealed important insights into the epidemiology and mechanisms of drug resistance of malaria. However, WGS of P. vivax is challenging due to low parasite levels in humans and the lack of a routine system to culture the parasites. Selective whole-genome amplification (SWGA) preferentially amplifies the genomes of pathogens from mixtures of target and host gDNA. Here, we demonstrate that SWGA is a simple, robust method that can be used to enrich P. vivax genomic DNA (gDNA) from unprocessed human blood samples and dried blood spots for cost-effective, high-quality WGS.
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36
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Arias-Gonzalez JR. Information management in DNA replication modeled by directional, stochastic chains with memory. J Chem Phys 2016; 145:185103. [DOI: 10.1063/1.4967335] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- J. Ricardo Arias-Gonzalez
- Instituto Madrileño de Estudios Avanzados en Nanociencia, CNB-CSIC-IMDEA Nanociencia Associated Unit “Unidad de Nanobiotecnología,” C/Faraday 9, Cantoblanco, 28049 Madrid, Spain
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37
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The Power of Force: Insights into the Protein Folding Process Using Single-Molecule Force Spectroscopy. J Mol Biol 2016; 428:4245-4257. [PMID: 27639437 DOI: 10.1016/j.jmb.2016.09.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/07/2016] [Accepted: 09/07/2016] [Indexed: 01/03/2023]
Abstract
One of the major challenges in modern biophysics is observing and understanding conformational changes during complex molecular processes, from the fundamental protein folding to the function of molecular machines. Single-molecule techniques have been one of the major driving forces of the huge progress attained in the last few years. Recent advances in resolution of the experimental setups, aided by theoretical developments and molecular dynamics simulations, have revealed a much higher degree of complexity inside these molecular processes than previously reported using traditional ensemble measurements. This review sums up the evolution of these developments and gives an outlook on prospective discoveries.
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38
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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.
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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.
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39
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Salas M, Holguera I, Redrejo-Rodríguez M, de Vega M. DNA-Binding Proteins Essential for Protein-Primed Bacteriophage Φ29 DNA Replication. Front Mol Biosci 2016; 3:37. [PMID: 27547754 PMCID: PMC4974454 DOI: 10.3389/fmolb.2016.00037] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 07/20/2016] [Indexed: 01/25/2023] Open
Abstract
Bacillus subtilis phage Φ29 has a linear, double-stranded DNA 19 kb long with an inverted terminal repeat of 6 nucleotides and a protein covalently linked to the 5′ ends of the DNA. This protein, called terminal protein (TP), is the primer for the initiation of replication, a reaction catalyzed by the viral DNA polymerase at the two DNA ends. The DNA polymerase further elongates the nascent DNA chain in a processive manner, coupling strand displacement with elongation. The viral protein p5 is a single-stranded DNA binding protein (SSB) that binds to the single strands generated by strand displacement during the elongation process. Viral protein p6 is a double-stranded DNA binding protein (DBP) that preferentially binds to the origins of replication at the Φ29 DNA ends and is required for the initiation of replication. Both SSB and DBP are essential for Φ29 DNA amplification. This review focuses on the role of these phage DNA-binding proteins in Φ29 DNA replication both in vitro and in vivo, as well as on the implication of several B. subtilis DNA-binding proteins in different processes of the viral cycle. We will revise the enzymatic activities of the Φ29 DNA polymerase: TP-deoxynucleotidylation, processive DNA polymerization coupled to strand displacement, 3′–5′ exonucleolysis and pyrophosphorolysis. The resolution of the Φ29 DNA polymerase structure has shed light on the translocation mechanism and the determinants responsible for processivity and strand displacement. These two properties have made Φ29 DNA polymerase one of the main enzymes used in the current DNA amplification technologies. The determination of the structure of Φ29 TP revealed the existence of three domains: the priming domain, where the primer residue Ser232, as well as Phe230, involved in the determination of the initiating nucleotide, are located, the intermediate domain, involved in DNA polymerase binding, and the N-terminal domain, responsible for DNA binding and localization of the TP at the bacterial nucleoid, where viral DNA replication takes place. The biochemical properties of the Φ29 DBP and SSB and their function in the initiation and elongation of Φ29 DNA replication, respectively, will be described.
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Affiliation(s)
- Margarita Salas
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas), Universidad Autónoma de Madrid Madrid, Spain
| | - Isabel Holguera
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas), Universidad Autónoma de Madrid Madrid, Spain
| | - Modesto Redrejo-Rodríguez
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas), Universidad Autónoma de Madrid Madrid, Spain
| | - Miguel de Vega
- Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas), Universidad Autónoma de Madrid Madrid, Spain
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40
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Kemmerich FE, Kasaciunaite K, Seidel R. Modular magnetic tweezers for single-molecule characterizations of helicases. Methods 2016; 108:4-13. [PMID: 27402355 DOI: 10.1016/j.ymeth.2016.07.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 07/05/2016] [Accepted: 07/06/2016] [Indexed: 01/09/2023] Open
Abstract
Magnetic tweezers provide a versatile toolkit supporting the mechanistic investigation of helicases. In the present article, we show that custom magnetic tweezers setups are straightforward to construct and can easily be extended to provide adaptable platforms, capable of addressing a multitude of enquiries regarding the functions of these fascinating molecular machines. We first address the fundamental components of a basic magnetic tweezers scheme and review some previous results to demonstrate the versatility of this instrument. We then elaborate on several extensions to the basic magnetic tweezers scheme, and demonstrate their applications with data from ongoing research. As our methodological overview illustrates, magnetic tweezers are an extremely useful tool for the characterization of helicases and a custom built instrument can be specifically tailored to suit the experimenter's needs.
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Affiliation(s)
- Felix E Kemmerich
- Molecular Biophysics Group, Institute of Experimental Physics I, Universität Leipzig, 04103 Leipzig, Germany
| | - Kristina Kasaciunaite
- Molecular Biophysics Group, Institute of Experimental Physics I, Universität Leipzig, 04103 Leipzig, Germany
| | - Ralf Seidel
- Molecular Biophysics Group, Institute of Experimental Physics I, Universität Leipzig, 04103 Leipzig, Germany.
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41
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Abstract
The requirement of DNA polymerases for a 3'-hydroxyl (3'-OH) group to prime DNA synthesis raised the question about how the ends of linear chromosomes could be replicated. Among the strategies that have evolved to handle the end replication problem, a group of linear phages and eukaryotic and archaeal viruses, among others, make use of a protein (terminal protein, TP) that primes DNA synthesis from the end of their genomes. The replicative DNA polymerase recognizes the OH group of a specific residue in the TP to initiate replication that is guided by an internal 3' nucleotide of the template strand. By a sliding-back mechanism or variants of it the terminal nucleotide(s) is(are) recovered and the TP becomes covalently attached to the genome ends. Bacillus subtilis phage ϕ29 is the organism in which such a mechanism has been studied more extensively, having allowed to lay the foundations of the so-called protein-primed replication mechanism. Here we focus on the main biochemical and structural features of the two main proteins responsible for the protein-primed initiation step: the DNA polymerase and the TP. Thus, we will discuss the structural determinants of the DNA polymerase responsible for its ability to use sequentially a TP and a DNA as primers, as well as for its inherent capacity to couple high processive synthesis to strand displacement. On the other hand, we will review how TP primes initiation followed by a transition step for further DNA-primed replication by the same polymerase molecule. Finally, we will review how replication is compartmentalized in vivo.
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Affiliation(s)
- M Salas
- Instituto de Biología Molecular "Eladio Viñuela" (CSIC), Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
| | - M de Vega
- Instituto de Biología Molecular "Eladio Viñuela" (CSIC), Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
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Dahl JM, Lieberman KR, Wang H. Modulation of DNA Polymerase Noncovalent Kinetic Transitions by Divalent Cations. J Biol Chem 2016; 291:6456-70. [PMID: 26797125 PMCID: PMC4813572 DOI: 10.1074/jbc.m115.701797] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/02/2016] [Indexed: 11/06/2022] Open
Abstract
Replicative DNA polymerases (DNAPs) require divalent metal cations for phosphodiester bond formation in the polymerase site and for hydrolytic editing in the exonuclease site. Me(2+) ions are intimate architectural components of each active site, where they are coordinated by a conserved set of amino acids and functional groups of the reaction substrates. Therefore Me(2+) ions can influence the noncovalent transitions that occur during each nucleotide addition cycle. Using a nanopore, transitions in individual Φ29 DNAP complexes are resolved with single-nucleotide spatial precision and sub-millisecond temporal resolution. We studied Mg(2+) and Mn(2+), which support catalysis, and Ca(2+), which supports deoxynucleoside triphosphate (dNTP) binding but not catalysis. We examined their effects on translocation, dNTP binding, and primer strand transfer between the polymerase and exonuclease sites. All three metals cause a concentration-dependent shift in the translocation equilibrium, predominantly by decreasing the forward translocation rate. Me(2+) also promotes an increase in the backward translocation rate that is dependent upon the primer terminal 3'-OH group. Me(2+) modulates the translocation rates but not their response to force, suggesting that Me(2+) does not affect the distance to the transition state of translocation. Absent Me(2+), the primer strand transfer pathway between the polymerase and exonuclease sites displays additional kinetic states not observed at >1 mm Me(2+). Complementary dNTP binding is affected by Me(2+) identity, with Ca(2+) affording the highest affinity, followed by Mn(2+), and then Mg(2+). Both Ca(2+) and Mn(2+) substantially decrease the dNTP dissociation rate relative to Mg(2+), while Ca(2+) also increases the dNTP association rate.
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Affiliation(s)
- Joseph M Dahl
- From the Departments of Biomolecular Engineering and
| | | | - Hongyun Wang
- Applied Mathematics and Statistics, University of California, Santa Cruz, California 95064
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43
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Tu J, Guo J, Li J, Gao S, Yao B, Lu Z. Systematic Characteristic Exploration of the Chimeras Generated in Multiple Displacement Amplification through Next Generation Sequencing Data Reanalysis. PLoS One 2015; 10:e0139857. [PMID: 26440104 PMCID: PMC4595205 DOI: 10.1371/journal.pone.0139857] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/16/2015] [Indexed: 11/18/2022] Open
Abstract
Background The chimeric sequences produced by phi29 DNA polymerase, which are named as chimeras, influence the performance of the multiple displacement amplification (MDA) and also increase the difficulty of sequence data process. Despite several articles have reported the existence of chimeric sequence, there was only one research focusing on the structure and generation mechanism of chimeras, and it was merely based on hundreds of chimeras found in the sequence data of E. coli genome. Method We finished data mining towards a series of Next Generation Sequencing (NGS) reads which were used for whole genome haplotype assembling in a primary study. We established a bioinformatics pipeline based on subsection alignment strategy to discover all the chimeras inside and achieve their structural visualization. Then, we artificially defined two statistical indexes (the chimeric distance and the overlap length), and their regular abundance distribution helped illustrate of the structural characteristics of the chimeras. Finally we analyzed the relationship between the chimera type and the average insertion size, so that illustrate a method to decrease the proportion of wasted data in the procedure of DNA library construction. Results/Conclusion 131.4 Gb pair-end (PE) sequence data was reanalyzed for the chimeras. Totally, 40,259,438 read pairs (6.19%) with chimerism were discovered among 650,430,811 read pairs. The chimeric sequences are consisted of two or more parts which locate inconsecutively but adjacently on the chromosome. The chimeric distance between the locations of adjacent parts on the chromosome followed an approximate bimodal distribution ranging from 0 to over 5,000 nt, whose peak was at about 250 to 300 nt. The overlap length of adjacent parts followed an approximate Poisson distribution and revealed a peak at 6 nt. Moreover, unmapped chimeras, which were classified as the wasted data, could be reduced by properly increasing the length of the insertion segment size through a linear correlation analysis. Significance This study exhibited the profile of the phi29MDA chimeras by tens of millions of chimeric sequences, and helped understand the amplification mechanism of the phi29 DNA polymerase. Our work also illustrated the importance of NGS data reanalysis, not only for the improvement of data utilization efficiency, but also for more potential genomic information.
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Affiliation(s)
- Jing Tu
- State Key Lab of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Jing Guo
- State Key Lab of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Junji Li
- State Key Lab of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Shen Gao
- State Key Lab of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Bei Yao
- State Key Lab of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Zuhong Lu
- State Key Lab of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
- * E-mail:
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44
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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.
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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
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Morin JA, Cao FJ, Lázaro JM, Arias-Gonzalez JR, Valpuesta JM, Carrascosa JL, Salas M, Ibarra B. Mechano-chemical kinetics of DNA replication: identification of the translocation step of a replicative DNA polymerase. Nucleic Acids Res 2015; 43:3643-52. [PMID: 25800740 PMCID: PMC4402526 DOI: 10.1093/nar/gkv204] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 02/14/2015] [Accepted: 02/27/2015] [Indexed: 11/25/2022] Open
Abstract
During DNA replication replicative polymerases move in discrete mechanical steps along the DNA template. To address how the chemical cycle is coupled to mechanical motion of the enzyme, here we use optical tweezers to study the translocation mechanism of individual bacteriophage Phi29 DNA polymerases during processive DNA replication. We determine the main kinetic parameters of the nucleotide incorporation cycle and their dependence on external load and nucleotide (dNTP) concentration. The data is inconsistent with power stroke models for translocation, instead supports a loose-coupling mechanism between chemical catalysis and mechanical translocation during DNA replication. According to this mechanism the DNA polymerase works by alternating between a dNTP/PPi-free state, which diffuses thermally between pre- and post-translocated states, and a dNTP/PPi-bound state where dNTP binding stabilizes the post-translocated state. We show how this thermal ratchet mechanism is used by the polymerase to generate work against large opposing loads (∼50 pN).
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Affiliation(s)
- José A Morin
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, 28049 Madrid, Spain
| | - Francisco J Cao
- Departamento Física Atómica, Molecular y Nuclear, Universidad Complutense, 28040 Madrid, Spain
| | - José M Lázaro
- Centro de Biología Molecular 'Severo Ochoa' (CSIC-UAM), Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain
| | - J Ricardo Arias-Gonzalez
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia) & CNB-CSIC-IMDEA Nanociencia Associated Unit 'Unidad de Nanobiotecnología', 28049 Madrid, Spain
| | - José M Valpuesta
- Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain
| | - José L Carrascosa
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia) & CNB-CSIC-IMDEA Nanociencia Associated Unit 'Unidad de Nanobiotecnología', 28049 Madrid, Spain Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain
| | - Margarita Salas
- Centro de Biología Molecular 'Severo Ochoa' (CSIC-UAM), Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia) & CNB-CSIC-IMDEA Nanociencia Associated Unit 'Unidad de Nanobiotecnología', 28049 Madrid, Spain
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Mao Y, Liu M, Tram K, Gu J, Salena BJ, Jiang Y, Li Y. Optimal DNA templates for rolling circle amplification revealed by in vitro selection. Chemistry 2015; 21:8069-74. [PMID: 25877998 DOI: 10.1002/chem.201500994] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Indexed: 01/21/2023]
Abstract
Rolling circle amplification (RCA) has been widely used as an isothermal DNA amplification technique for diagnostic and bioanalytical applications. Because RCA involves repeated copying of the same circular DNA template by a DNA polymerase thousands of times, we hypothesized there exist DNA sequences that can function as optimal templates and produce more DNA amplicons within an allocated time. Herein we describe an in vitro selection effort conducted to search from a random sequence DNA pool for such templates for phi29 DNA polymerase, a frequently used polymerase for RCA. Diverse DNA molecules were isolated and they were characterized by richness in adenosine (A) and cytidine (C) nucleotides. The top ranked sequences exhibit superior RCA efficiency and the use of these templates for RCA results in significantly improved detection sensitivity. AC-rich sequences are expected to find useful applications for setting up effective RCA assays for biological sensing.
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Affiliation(s)
- Yu Mao
- Departments of Biochemistry and Biomedical Sciences and Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4K1 (Canada).,The Ministry-Province Jointly Constructed Base for State Key Laboratory, Shenzhen Key Laboratory of Chemical Biology, The Graduate School at Shenzhen, Tsinghua University, Shenzhen, Guangdong 518055 (P. R. China).,School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055 (P. R. China)
| | - Meng Liu
- Departments of Biochemistry and Biomedical Sciences and Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4K1 (Canada)
| | - Kha Tram
- Departments of Biochemistry and Biomedical Sciences and Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4K1 (Canada)
| | - Jimmy Gu
- Departments of Biochemistry and Biomedical Sciences and Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4K1 (Canada)
| | - Bruno J Salena
- Department of Medicine, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4K1 (Canada)
| | - Yuyang Jiang
- The Ministry-Province Jointly Constructed Base for State Key Laboratory, Shenzhen Key Laboratory of Chemical Biology, The Graduate School at Shenzhen, Tsinghua University, Shenzhen, Guangdong 518055 (P. R. China).
| | - Yingfu Li
- Departments of Biochemistry and Biomedical Sciences and Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4K1 (Canada).
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Dahl JM, Wang H, Lázaro JM, Salas M, Lieberman KR. Kinetic mechanisms governing stable ribonucleotide incorporation in individual DNA polymerase complexes. Biochemistry 2014; 53:8061-76. [PMID: 25478721 PMCID: PMC4283934 DOI: 10.1021/bi501216a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Ribonucleoside triphosphates (rNTPs) are frequently incorporated during DNA synthesis by replicative DNA polymerases (DNAPs), and once incorporated are not efficiently edited by the DNAP exonucleolytic function. We examined the kinetic mechanisms that govern selection of complementary deoxyribonucleoside triphosphates (dNTPs) over complementary rNTPs and that govern the probability of a complementary ribonucleotide at the primer terminus escaping exonucleolytic editing and becoming stably incorporated. We studied the quantitative responses of individual Φ29 DNAP complexes to ribonucleotides using a kinetic framework, based on our prior work, in which transfer of the primer strand from the polymerase to exonuclease site occurs prior to translocation, and translocation precedes dNTP binding. We determined transition rates between the pre-translocation and post-translocation states, between the polymerase and exonuclease sites, and for dNTP or rNTP binding, with single-nucleotide spatial precision and submillisecond temporal resolution, from ionic current time traces recorded when individual DNAP complexes are held atop a nanopore in an electric field. The predominant response to the presence of a ribonucleotide in Φ29 DNAP complexes before and after covalent incorporation is significant destabilization, relative to the presence of a deoxyribonucleotide. This destabilization is manifested in the post-translocation state prior to incorporation as a substantially higher rNTP dissociation rate and manifested in the pre-translocation state after incorporation as rate increases for both primer strand transfer to the exonuclease site and the forward translocation, with the probability of editing not directly increased. In the post-translocation state, the primer terminal 2'-OH group also destabilizes dNTP binding.
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Affiliation(s)
- Joseph M Dahl
- Department of Biomolecular Engineering, ‡Department of Applied Mathematics and Statistics, and §Department of Computer Engineering, Baskin School of Engineering, University of California , Santa Cruz, California 95064, United States
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48
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Oyola SO, Manske M, Campino S, Claessens A, Hamilton WL, Kekre M, Drury E, Mead D, Gu Y, Miles A, MacInnis B, Newbold C, Berriman M, Kwiatkowski DP. Optimized whole-genome amplification strategy for extremely AT-biased template. DNA Res 2014; 21:661-71. [PMID: 25240466 PMCID: PMC4263299 DOI: 10.1093/dnares/dsu028] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Pathogen genome sequencing directly from clinical samples is quickly gaining importance in genetic and medical research studies. However, low DNA yield from blood-borne pathogens is often a limiting factor. The problem worsens in extremely base-biased genomes such as the AT-rich Plasmodium falciparum. We present a strategy for whole-genome amplification (WGA) of low-yield samples from P. falciparum prior to short-read sequencing. We have developed WGA conditions that incorporate tetramethylammonium chloride for improved amplification and coverage of AT-rich regions of the genome. We show that this method reduces amplification bias and chimera formation. Our data show that this method is suitable for as low as 10 pg input DNA, and offers the possibility of sequencing the parasite genome from small blood samples.
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Affiliation(s)
| | | | | | | | | | - Mihir Kekre
- Wellcome Trust Sanger Institute, Hinxton, UK
| | | | - Daniel Mead
- Wellcome Trust Sanger Institute, Hinxton, UK
| | - Yong Gu
- Wellcome Trust Sanger Institute, Hinxton, UK
| | - Alistair Miles
- MRC Centre for Genomics and Global Health, University of Oxford, Oxford OX3 7BN, UK Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Bronwyn MacInnis
- Wellcome Trust Sanger Institute, Hinxton, UK MRC Centre for Genomics and Global Health, University of Oxford, Oxford OX3 7BN, UK
| | - Chris Newbold
- Wellcome Trust Sanger Institute, Hinxton, UK Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | | | - Dominic P Kwiatkowski
- Wellcome Trust Sanger Institute, Hinxton, UK MRC Centre for Genomics and Global Health, University of Oxford, Oxford OX3 7BN, UK Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
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49
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Stephenson W, Wan G, Tenenbaum SA, Li PTX. Nanomanipulation of single RNA molecules by optical tweezers. J Vis Exp 2014. [PMID: 25177917 DOI: 10.3791/51542] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
A large portion of the human genome is transcribed but not translated. In this post genomic era, regulatory functions of RNA have been shown to be increasingly important. As RNA function often depends on its ability to adopt alternative structures, it is difficult to predict RNA three-dimensional structures directly from sequence. Single-molecule approaches show potentials to solve the problem of RNA structural polymorphism by monitoring molecular structures one molecule at a time. This work presents a method to precisely manipulate the folding and structure of single RNA molecules using optical tweezers. First, methods to synthesize molecules suitable for single-molecule mechanical work are described. Next, various calibration procedures to ensure the proper operations of the optical tweezers are discussed. Next, various experiments are explained. To demonstrate the utility of the technique, results of mechanically unfolding RNA hairpins and a single RNA kissing complex are used as evidence. In these examples, the nanomanipulation technique was used to study folding of each structural domain, including secondary and tertiary, independently. Lastly, the limitations and future applications of the method are discussed.
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Affiliation(s)
- William Stephenson
- Nanoscale Engineering Graduate Program, College of Nanoscale Science and Engineering, University at Albany, State University of New York
| | - Gorby Wan
- Nanoscale Science Undergraduate Program, College of Nanoscale Science and Engineering, University at Albany, State University of New York
| | - Scott A Tenenbaum
- Nanobioscience Constellation, College of Nanoscale Science and Engineering, University at Albany, State University of New York; The RNA Institute, University at Albany, State University of New York
| | - Pan T X Li
- The RNA Institute, University at Albany, State University of New York; Department of Biological Sciences, University at Albany, State University of New York;
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Affiliation(s)
- Thomas T. Perkins
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309;
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado 80309
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