1
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Ngo TTM, Liu B, Wang F, Basu A, Wu C, Ha T. Dependence of nucleosome mechanical stability on DNA mismatches. eLife 2024; 13:RP95514. [PMID: 38656237 DOI: 10.7554/elife.95514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Abstract
The organization of nucleosomes into chromatin and their accessibility are shaped by local DNA mechanics. Conversely, nucleosome positions shape genetic variations, which may originate from mismatches during replication and chemical modification of DNA. To investigate how DNA mismatches affect the mechanical stability and the exposure of nucleosomal DNA, we used an optical trap combined with single-molecule FRET and a single-molecule FRET cyclization assay. We found that a single base-pair C-C mismatch enhances DNA bendability and nucleosome mechanical stability for the 601-nucleosome positioning sequence. An increase in force required for DNA unwrapping from the histone core is observed for single base-pair C-C mismatches placed at three tested positions: at the inner turn, at the outer turn, or at the junction of the inner and outer turn of the nucleosome. The results support a model where nucleosomal DNA accessibility is reduced by mismatches, potentially explaining the preferred accumulation of single-nucleotide substitutions in the nucleosome core and serving as the source of genetic variation during evolution and cancer progression. Mechanical stability of an intact nucleosome, that is mismatch-free, is also dependent on the species as we find that yeast nucleosomes are mechanically less stable and more symmetrical in the outer turn unwrapping compared to Xenopus nucleosomes.
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Affiliation(s)
- Thuy T M Ngo
- Department of Physics, Center for Physics in Living Cells University of Illinois Urbana-Champaign, Urbana, United States
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, United States
- Cancer Early Detection Advanced Research Center (CEDAR), Knight Cancer Institute, Oregon Health and Science University, Portland, United States
- Department of Biomedical Engineering, Oregon Health and Science University, Portland, United States
- Division of Oncological Sciences, Oregon Health and Science University, Portland, United States
| | - Bailey Liu
- Department of Biophysics, Johns Hopkins University, Baltimore, United States
| | - Feng Wang
- Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, United States
| | - Aakash Basu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, United States
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Carl Wu
- Department of Biology, Johns Hopkins University, Baltimore, United States
- Department of Molecular Biology and Genetics, Johns Hopkins University, Baltimore, United States
| | - Taekjip Ha
- Department of Physics, Center for Physics in Living Cells University of Illinois Urbana-Champaign, Urbana, United States
- Department of Biophysics, Johns Hopkins University, Baltimore, United States
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, United States
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, United States
- Department of Pediatrics, Harvard Medical School, Boston, United States
- Howard Hughes Medical Institute, Boston, United States
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2
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Back G, Walther D. Predictions of DNA mechanical properties at a genomic scale reveal potentially new functional roles of DNA flexibility. NAR Genom Bioinform 2023; 5:lqad097. [PMID: 37954573 PMCID: PMC10632188 DOI: 10.1093/nargab/lqad097] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 09/28/2023] [Accepted: 10/25/2023] [Indexed: 11/14/2023] Open
Abstract
Mechanical properties of DNA have been implied to influence many of its biological functions. Recently, a new high-throughput method, called loop-seq, which allows measuring the intrinsic bendability of DNA fragments, has been developed. Using loop-seq data, we created a deep learning model to explore the biological significance of local DNA flexibility in a range of different species from different kingdoms. Consistently, we observed a characteristic and largely dinucleotide-composition-driven change of local flexibility near transcription start sites. In the presence of a TATA-box, a pronounced peak of high flexibility can be observed. Furthermore, depending on the transcription factor investigated, flanking-sequence-dependent DNA flexibility was identified as a potential factor influencing DNA binding. Compared to randomized genomic sequences, depending on species and taxa, actual genomic sequences were observed both with increased and lowered flexibility. Furthermore, in Arabidopsis thaliana, mutation rates, both de novo and fixed, were found to be associated with relatively rigid sequence regions. Our study presents a range of significant correlations between characteristic DNA mechanical properties and genomic features, the significance of which with regard to detailed molecular relevance awaits further theoretical and experimental exploration.
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Affiliation(s)
- Georg Back
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, Potsdam-Golm 14476, Germany
| | - Dirk Walther
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, Potsdam-Golm 14476, Germany
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3
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Yi J, Yeou S, Lee NK. DNA Bending Force Facilitates Z-DNA Formation under Physiological Salt Conditions. J Am Chem Soc 2022; 144:13137-13145. [PMID: 35839423 PMCID: PMC9335521 DOI: 10.1021/jacs.2c02466] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Z-DNA, a noncanonical helical structure of double-stranded DNA (dsDNA), plays pivotal roles in various biological processes, including transcription regulation. Mechanical stresses on dsDNA, such as twisting and stretching, help to form Z-DNA. However, the effect of DNA bending, one of the most common dsDNA deformations, on Z-DNA formation is utterly unknown. Here, we show that DNA bending induces the formation of Z-DNA, that is, more Z-DNA is formed as the bending force becomes stronger. We regulated the bending force on dsDNA by using D-shaped DNA nanostructures. The B-Z transition was observed by single-molecule fluorescence resonance energy transfer. We found that as the bending force became stronger, Z-DNA was formed at lower Mg2+ concentrations. When dsDNA contained cytosine methylations, the B-Z transition occurred at 78 mM Mg2+ (midpoint) in the absence of the bending force. However, the B-Z transition occurred at a 28-fold lower Mg2+ concentration (2.8 mM) in the presence of the bending force. Monte Carlo simulation suggested that the B-Z transition stabilizes the bent form via the formation of the B-Z junction with base extrusion, which effectively releases the bending stress on DNA. Our results clearly show that the bending force facilitates the B-Z transition under physiological salt conditions.
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Affiliation(s)
- Jaehun Yi
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Sanghun Yeou
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Nam Ki Lee
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
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4
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Yeou S, Hwang J, Yi J, Kim C, Kim SK, Lee NK. Cytosine methylation regulates DNA bendability depending on the curvature. Chem Sci 2022; 13:7516-7525. [PMID: 35872822 PMCID: PMC9242020 DOI: 10.1039/d1sc07115g] [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: 12/21/2021] [Accepted: 06/01/2022] [Indexed: 11/21/2022] Open
Abstract
Cytosine methylation plays an essential role in many biological processes, such as nucleosome inactivation and regulation of gene expression. The modulation of DNA mechanics may be one of the regulatory mechanisms influenced by cytosine methylation. However, it remains unclear how methylation influences DNA mechanics. Here, we show that methylation has contrasting effects on the bending property of dsDNA depending on DNA curvature. We directly applied bending force on 30 base pairs of dsDNA using a D-shaped DNA nanostructure and measured the degree of bending using single-molecule fluorescence resonance energy transfer without surface immobilization. When dsDNA is weakly bent, methylation increases the stiffness of dsDNA. The stiffness of dsDNA increased by approximately 8% with a single methylation site for 30 bp dsDNA. When dsDNA is highly bent by a strong force, it forms a kink, i.e., a sharp bending of dsDNA. Under strong bending, methylation destabilizes the non-kink form compared with the kink form, which makes dsDNA near the kink region apparently more bendable. However, if the kink region is methylated, the kink form is destabilized, and dsDNA becomes stiffer. As a result, methylation increases the stiffness of weakly bent dsDNA and concurrently can promote kink formation, which may stabilize the nucleosome structure. Our results provide new insight into the effect of methylation, showing that cytosine methylation has opposite effects on DNA mechanics depending on its curvature and methylation location.
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Affiliation(s)
- Sanghun Yeou
- Department of Chemistry, Seoul National University 08832 Seoul Republic of Korea
| | - Jihee Hwang
- Department of Chemistry, Seoul National University 08832 Seoul Republic of Korea
| | - Jaehun Yi
- Department of Chemistry, Seoul National University 08832 Seoul Republic of Korea
| | - Cheolhee Kim
- National Science Museum Daejeon 34143 Republic of Korea
| | - Seong Keun Kim
- Department of Chemistry, Seoul National University 08832 Seoul Republic of Korea
| | - Nam Ki Lee
- Department of Chemistry, Seoul National University 08832 Seoul Republic of Korea
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5
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Yeou S, Lee NK. Single-Molecule Methods for Investigating the Double-Stranded DNA Bendability. Mol Cells 2022; 45:33-40. [PMID: 34470919 PMCID: PMC8819492 DOI: 10.14348/molcells.2021.0182] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 11/27/2022] Open
Abstract
The various DNA-protein interactions associated with the expression of genetic information involve double-stranded DNA (dsDNA) bending. Due to the importance of the formation of the dsDNA bending structure, dsDNA bending properties have long been investigated in the biophysics field. Conventionally, DNA bendability is characterized by innate averaging data from bulk experiments. The advent of single-molecule methods, such as atomic force microscopy, optical and magnetic tweezers, tethered particle motion, and single-molecule fluorescence resonance energy transfer measurement, has provided valuable tools to investigate not only the static structures but also the dynamic properties of bent dsDNA. Here, we reviewed the single-molecule methods that have been used for investigating dsDNA bendability and new findings related to dsDNA bending. Single-molecule approaches are promising tools for revealing the unknown properties of dsDNA related to its bending, particularly in cells.
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Affiliation(s)
- Sanghun Yeou
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Nam Ki Lee
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
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6
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Li K, Carroll M, Vafabakhsh R, Wang XA, Wang JP. OUP accepted manuscript. Nucleic Acids Res 2022; 50:3142-3154. [PMID: 35288750 PMCID: PMC8989542 DOI: 10.1093/nar/gkac162] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/16/2022] [Accepted: 02/23/2022] [Indexed: 11/16/2022] Open
Abstract
DNA mechanical properties play a critical role in every aspect of DNA-dependent biological processes. Recently a high throughput assay named loop-seq has been developed to quantify the intrinsic bendability of a massive number of DNA fragments simultaneously. Using the loop-seq data, we develop a software tool, DNAcycP, based on a deep-learning approach for intrinsic DNA cyclizability prediction. We demonstrate DNAcycP predicts intrinsic DNA cyclizability with high fidelity compared to the experimental data. Using an independent dataset from in vitro selection for enrichment of loopable sequences, we further verified the predicted cyclizability score, termed C-score, can well distinguish DNA fragments with different loopability. We applied DNAcycP to multiple species and compared the C-scores with available high-resolution chemical nucleosome maps. Our analyses showed that both yeast and mouse genomes share a conserved feature of high DNA bendability spanning nucleosome dyads. Additionally, we extended our analysis to transcription factor binding sites and surprisingly found that the cyclizability is substantially elevated at CTCF binding sites in the mouse genome. We further demonstrate this distinct mechanical property is conserved across mammalian species and is inherent to CTCF binding DNA motif.
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Affiliation(s)
- Keren Li
- Department of Statistics, Northwestern University, 633 Clark Street, Evanston, IL 60208, USA
- NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, IL 60208, USA
| | - Matthew Carroll
- Weinberg College IT Solutions (WITS), Northwestern University, 633 Clark Street, Evanston, IL 60208, USA
| | - Reza Vafabakhsh
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Xiaozhong A Wang
- Correspondence may also be addressed to Xiaozhong A. Wang. Tel: +1 847 467 4897;
| | - Ji-Ping Wang
- To whom correspondence should be addressed. Tel: +1 847 467 6896;
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7
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Loop-seq: A high-throughput technique to measure the mesoscale mechanical properties of DNA. Methods Enzymol 2021; 661:305-326. [PMID: 34776217 DOI: 10.1016/bs.mie.2021.08.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The local mechanical properties of the DNA polymer influence molecular processes in biology that require mechanical deformations of DNA. Lack of suitable high-throughput experimental techniques had precluded measuring how these properties might vary with sequence along the vast lengths of genomes. Here, we present a detailed protocol for a recently developed experimental technique called loop-seq, which measures at least one local mechanical property of DNA-its propensity to cyclize-in genome-scale throughput. Loop-seq has been used to obtain experimentally derived genome-wide maps of a physical property of DNA. Such measurements have revealed that diverse DNA-deforming processes involved in chromatin organization at various genomic loci are regulated by the genetically encoded, sequence-dependent variations in the mechanical properties of DNA.
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8
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Abstract
DNA dynamics can only be understood by taking into account its complex mechanical behavior at different length scales. At the micrometer level, the mechanical properties of single DNA molecules have been well-characterized by polymer models and are commonly quantified by a persistence length of 50 nm (~150 bp). However, at the base pair level (~3.4 Å), the dynamics of DNA involves complex molecular mechanisms that are still being deciphered. Here, we review recent single-molecule experiments and molecular dynamics simulations that are providing novel insights into DNA mechanics from such a molecular perspective. We first discuss recent findings on sequence-dependent DNA mechanical properties, including sequences that resist mechanical stress and sequences that can accommodate strong deformations. We then comment on the intricate effects of cytosine methylation and DNA mismatches on DNA mechanics. Finally, we review recently reported differences in the mechanical properties of DNA and double-stranded RNA, the other double-helical carrier of genetic information. A thorough examination of the recent single-molecule literature permits establishing a set of general 'rules' that reasonably explain the mechanics of nucleic acids at the base pair level. These simple rules offer an improved description of certain biological systems and might serve as valuable guidelines for future design of DNA and RNA nanostructures.
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9
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Basu A, Bobrovnikov DG, Ha T. DNA mechanics and its biological impact. J Mol Biol 2021; 433:166861. [PMID: 33539885 DOI: 10.1016/j.jmb.2021.166861] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 02/06/2023]
Abstract
Almost all nucleoprotein interactions and DNA manipulation events involve mechanical deformations of DNA. Extraordinary progresses in single-molecule, structural, and computational methods have characterized the average mechanical properties of DNA, such as bendability and torsional rigidity, in high resolution. Further, the advent of sequencing technology has permitted measuring, in high-throughput, how such mechanical properties vary with sequence and epigenetic modifications along genomes. We review these recent technological advancements, and discuss how they have contributed to the emerging idea that variations in the mechanical properties of DNA play a fundamental role in regulating, genome-wide, diverse processes involved in chromatin organization.
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Affiliation(s)
- Aakash Basu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Dmitriy G Bobrovnikov
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Baltimore, MD 21205, USA
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10
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Park G, Cho MK, Jung Y. Sequence-Dependent Kink Formation in Short DNA Loops: Theory and Molecular Dynamics Simulations. J Chem Theory Comput 2021; 17:1308-1317. [PMID: 33570937 DOI: 10.1021/acs.jctc.0c01116] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Kink formation is essential in highly bent DNA complexed with gene regulatory proteins such as histones to release the bending stress stored within the DNA duplex. Local opening of the double-stranded DNA creates a sharp turn along the specific sequence, which leads to the global bending of the DNA strand. Despite the critical role of kink formation, it is still challenging to predict the position of kink formation for a given DNA sequence. In this study, we propose a theoretical model and perform molecular dynamics simulations to quantify the sequence-dependent kink probability of a strongly bent DNA. By incorporating the elastic bending energy and the sequence-specific thermodynamic parameters, we investigate the importance of the DNA sequence on kink formation. We find that the sequence with TA dinucleotide repeats flanked by GC steps increases the kink propensity by more than an order of magnitude under the same bending stress. The number of base pairs involved in the local opening is found to be coupled with the sequence-specific bubble formation free energy. Our study elucidates the molecular origin of the sequence heterogeneity on kink formation, which is fundamental to understanding protein-DNA recognition.
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Affiliation(s)
- Gyehyun Park
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Myung Keun Cho
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - YounJoon Jung
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
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11
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Basu A, Bobrovnikov DG, Qureshi Z, Kayikcioglu T, Ngo TTM, Ranjan A, Eustermann S, Cieza B, Morgan MT, Hejna M, Rube HT, Hopfner KP, Wolberger C, Song JS, Ha T. Measuring DNA mechanics on the genome scale. Nature 2021; 589:462-467. [PMID: 33328628 PMCID: PMC7855230 DOI: 10.1038/s41586-020-03052-3] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 10/21/2020] [Indexed: 12/21/2022]
Abstract
Mechanical deformations of DNA such as bending are ubiquitous and have been implicated in diverse cellular functions1. However, the lack of high-throughput tools to measure the mechanical properties of DNA has limited our understanding of how DNA mechanics influence chromatin transactions across the genome. Here we develop 'loop-seq'-a high-throughput assay to measure the propensity for DNA looping-and determine the intrinsic cyclizabilities of 270,806 50-base-pair DNA fragments that span Saccharomyces cerevisiae chromosome V, other genomic regions, and random sequences. We found sequence-encoded regions of unusually low bendability within nucleosome-depleted regions upstream of transcription start sites (TSSs). Low bendability of linker DNA inhibits nucleosome sliding into the linker by the chromatin remodeller INO80, which explains how INO80 can define nucleosome-depleted regions in the absence of other factors2. Chromosome-wide, nucleosomes were characterized by high DNA bendability near dyads and low bendability near linkers. This contrast increases for deeper gene-body nucleosomes but disappears after random substitution of synonymous codons, which suggests that the evolution of codon choice has been influenced by DNA mechanics around gene-body nucleosomes. Furthermore, we show that local DNA mechanics affect transcription through TSS-proximal nucleosomes. Overall, this genome-scale map of DNA mechanics indicates a 'mechanical code' with broad functional implications.
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Affiliation(s)
- Aakash Basu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Dmitriy G Bobrovnikov
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zan Qureshi
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA
| | - Tunc Kayikcioglu
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Thuy T M Ngo
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Anand Ranjan
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Sebastian Eustermann
- Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany
| | - Basilio Cieza
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA
| | - Michael T Morgan
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Miroslav Hejna
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - H Tomas Rube
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Karl-Peter Hopfner
- Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany
| | - Cynthia Wolberger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jun S Song
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Cancer Center at Illinois, University of Illinois, Urbana, IL, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA.
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
- Howard Hughes Medical Institute, Baltimore, MD, USA.
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12
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Iqbal MJ, Li Z, Khan MA, Zhu Y, Hussain W, Su H, Qiu QM, Shoukat R, Li H. Studies on the structure and chirality of A-motif in adenosine monophosphate nucleotide metal coordination complexes. CrystEngComm 2021. [DOI: 10.1039/d1ce00276g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Structure and chirality of A-motif.
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Affiliation(s)
- Muhammad Javed Iqbal
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Beijing Institute of Technology
- Beijing 100081
- P. R. China
| | - Zhongkui Li
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Beijing Institute of Technology
- Beijing 100081
- P. R. China
| | - Maroof Ahmad Khan
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Beijing Institute of Technology
- Beijing 100081
- P. R. China
| | - Yanhong Zhu
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Beijing Institute of Technology
- Beijing 100081
- P. R. China
| | - Wajid Hussain
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Beijing Institute of Technology
- Beijing 100081
- P. R. China
| | - Hao Su
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Beijing Institute of Technology
- Beijing 100081
- P. R. China
| | - Qi-Ming Qiu
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Beijing Institute of Technology
- Beijing 100081
- P. R. China
| | - Rizwan Shoukat
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Beijing Institute of Technology
- Beijing 100081
- P. R. China
| | - Hui Li
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Beijing Institute of Technology
- Beijing 100081
- P. R. China
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13
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Freeland J, Zhang L, Wang ST, Ruiz M, Wang Y. Bent DNA Bows as Sensing Amplifiers for Detecting DNA-Interacting Salts and Molecules. SENSORS (BASEL, SWITZERLAND) 2020; 20:E3112. [PMID: 32486417 PMCID: PMC7309149 DOI: 10.3390/s20113112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 05/23/2020] [Accepted: 05/29/2020] [Indexed: 01/20/2023]
Abstract
Due to the central role of DNA, its interactions with inorganic salts and small organic molecules are important. For example, such interactions play important roles in various fundamental cellular processes in living systems and are involved in many DNA-damage related diseases. Strategies to improve the sensitivity of existing techniques for studying DNA interactions with other molecules would be appreciated in situations where the interactions are too weak. Here we report our development and demonstration of bent DNA bows for amplifying, sensing, and detecting the interactions of 14 inorganic salts and small organic molecules with DNA. With the bent DNA bows, these interactions were easily visualized and quantified in gel electrophoresis, which were difficult to measure without bending. In addition, the strength of the interactions of DNA with the various salts/molecules were quantified using the modified Hill equation. This work highlights the amplification effects of the bending elastic energy stored in the DNA bows and the potential use of the DNA bows for quantitatively measuring DNA interactions with small molecules as simple economic methods; it may also pave the way for exploiting the bent DNA bows for other applications such as screening DNA-interacting molecules and drugs.
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Affiliation(s)
- Jack Freeland
- Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA; (J.F.); (M.R.)
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Lihua Zhang
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA; (L.Z.); (S.-T.W.)
| | - Shih-Ting Wang
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA; (L.Z.); (S.-T.W.)
| | - Mason Ruiz
- Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA; (J.F.); (M.R.)
- Department of Biology, University of Arkansas, Fayetteville, AR 72701, USA
| | - Yong Wang
- Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA; (J.F.); (M.R.)
- Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR 72701, USA
- Microelectronics-Photonics Program, University of Arkansas, Fayetteville, AR 72701, USA
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14
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Jeong J, Kim HD. Base-Pair Mismatch Can Destabilize Small DNA Loops through Cooperative Kinking. PHYSICAL REVIEW LETTERS 2019; 122:218101. [PMID: 31283336 PMCID: PMC7819736 DOI: 10.1103/physrevlett.122.218101] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Indexed: 05/13/2023]
Abstract
Base-pair mismatch can relieve mechanical stress in highly strained DNA molecules, but how it affects their kinetic stability is not known. Using single-molecule fluorescence resonance energy transfer, we measured the lifetimes of tightly bent DNA loops with and without base-pair mismatch. Surprisingly, for loops captured by stackable sticky ends which leave single-stranded DNA breaks (or nicks) upon annealing, the mismatch decreased the loop lifetime despite reducing the overall bending stress, and the decrease was largest when the mismatch was placed at the DNA midpoint. These findings suggest that base-pair mismatch increases bending stress at the opposite side of the loop through an allosteric mechanism known as cooperative kinking. Based on this mechanism, we present a three-state model that explains the apparent dichotomy between thermodynamic and kinetic stability.
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