1
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Pokorná P, Mlýnský V, Bussi G, Šponer J, Stadlbauer P. Molecular dynamics simulations reveal the parallel stranded d(GGGA) 3GGG DNA quadruplex folds via multiple paths from a coil-like ensemble. Int J Biol Macromol 2024; 261:129712. [PMID: 38286387 DOI: 10.1016/j.ijbiomac.2024.129712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/10/2024] [Accepted: 01/16/2024] [Indexed: 01/31/2024]
Abstract
G-quadruplexes (G4s) are non-canonical nucleic acid structures that fold through complex processes. Characterization of the G4 folding landscape may help to elucidate biological roles of G4s but is challenging both experimentally and computationally. Here, we achieved complete folding of a three-quartet parallel DNA G4 with (GGGA)3GGG sequence using all-atom explicit-solvent enhanced-sampling molecular dynamics (MD) simulations. The simulations suggested early formation of guanine stacks in the G-tracts, which behave as semi-rigid blocks in the folding process. The folding continues via the formation of a collapsed compact coil-like ensemble. Structuring of the G4 from the coil then proceeds via various cross-like, hairpin, slip-stranded and two-quartet ensembles and can bypass the G-triplex structure. Folding of the parallel G4 does not appear to involve any salient intermediates and is a multi-pathway process. We also carried out an extended set of simulations of parallel G-hairpins. While parallel G-hairpins are extremely unstable when isolated, they are more stable inside the coil structure. On the methodology side, we show that the AMBER DNA force field predicts the folded G4 to be less stable than the unfolded ensemble, uncovering substantial force-field issues. Overall, we provide unique atomistic insights into the folding landscape of parallel-stranded G4 but also reveal limitations of current state-of-the-art MD techniques.
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Affiliation(s)
- Pavlína Pokorná
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Vojtěch Mlýnský
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati (SISSA), via Bonomea 265, Trieste 34136, Italy
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic.
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2
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Li Z, Hu R, Li T, Zhu J, You H, Li Y, Liu BF, Li C, Li Y, Yang Y. A TeZla micromixer for interrogating the early and broad folding landscape of G-quadruplex via multistage velocity descending. Proc Natl Acad Sci U S A 2024; 121:e2315401121. [PMID: 38232280 PMCID: PMC10823215 DOI: 10.1073/pnas.2315401121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 12/17/2023] [Indexed: 01/19/2024] Open
Abstract
Biomacromolecular folding kinetics involves fast folding events and broad timescales. Current techniques face limitations in either the required time resolution or the observation window. In this study, we developed the TeZla micromixer, integrating Tesla and Zigzag microstructures with a multistage velocity descending strategy. TeZla achieves a significant short mixing dead time (40 µs) and a wide time window covering four orders of magnitude (up to 300 ms). Using this unique micromixer, we explored the folding landscape of c-Myc G4 and its noncanonical-G4 derivatives with different loop lengths or G-vacancy sites. Our findings revealed that c-Myc can bypass folding intermediates and directly adopt a G4 structure in the cation-deficient buffer. Moreover, we found that the loop length and specific G-vacancy site could affect the folding pathway and significantly slow down the folding rates. These results were also cross-validated with real-time NMR and circular dichroism. In conclusion, TeZla represents a versatile tool for studying biomolecular folding kinetics, and our findings may ultimately contribute to the design of drugs targeting G4 structures.
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Affiliation(s)
- Zheyu Li
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences—Wuhan National Laboratory for Optoelectronics, Wuhan430071, China
- Graduate University of Chinese Academy of Sciences, Beijing10049, China
| | - Rui Hu
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences—Wuhan National Laboratory for Optoelectronics, Wuhan430071, China
- Graduate University of Chinese Academy of Sciences, Beijing10049, China
| | - Tao Li
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences—Wuhan National Laboratory for Optoelectronics, Wuhan430071, China
- Graduate University of Chinese Academy of Sciences, Beijing10049, China
| | - Jiang Zhu
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences—Wuhan National Laboratory for Optoelectronics, Wuhan430071, China
- Graduate University of Chinese Academy of Sciences, Beijing10049, China
| | - Huijuan You
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan430030, China
| | - Yiwei Li
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics—Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan430074, China
| | - Bi-Feng Liu
- The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics—Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan430074, China
| | - Conggang Li
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences—Wuhan National Laboratory for Optoelectronics, Wuhan430071, China
- Graduate University of Chinese Academy of Sciences, Beijing10049, China
| | - Ying Li
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences—Wuhan National Laboratory for Optoelectronics, Wuhan430071, China
- Graduate University of Chinese Academy of Sciences, Beijing10049, China
| | - Yunhuang Yang
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences—Wuhan National Laboratory for Optoelectronics, Wuhan430071, China
- Graduate University of Chinese Academy of Sciences, Beijing10049, China
- Optics Valley Laboratory, Hubei430074, China
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3
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Ugrina M, Burkhart I, Müller D, Schwalbe H, Schwierz N. RNA G-quadruplex folding is a multi-pathway process driven by conformational entropy. Nucleic Acids Res 2024; 52:87-100. [PMID: 37986217 PMCID: PMC10783511 DOI: 10.1093/nar/gkad1065] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 09/25/2023] [Accepted: 10/25/2023] [Indexed: 11/22/2023] Open
Abstract
The kinetics of folding is crucial for the function of many regulatory RNAs including RNA G-quadruplexes (rG4s). Here, we characterize the folding pathways of a G-quadruplex from the telomeric repeat-containing RNA by combining all-atom molecular dynamics and coarse-grained simulations with circular dichroism experiments. The quadruplex fold is stabilized by cations and thus, the ion atmosphere forming a double layer surrounding the highly charged quadruplex guides the folding process. To capture the ionic double layer in implicit solvent coarse-grained simulations correctly, we develop a matching procedure based on all-atom simulations in explicit water. The procedure yields quantitative agreement between simulations and experiments as judged by the populations of folded and unfolded states at different salt concentrations and temperatures. Subsequently, we show that coarse-grained simulations with a resolution of three interaction sites per nucleotide are well suited to resolve the folding pathways and their intermediate states. The results reveal that the folding progresses from unpaired chain via hairpin, triplex and double-hairpin constellations to the final folded structure. The two- and three-strand intermediates are stabilized by transient Hoogsteen interactions. Each pathway passes through two on-pathway intermediates. We hypothesize that conformational entropy is a hallmark of rG4 folding. Conformational entropy leads to the observed branched multi-pathway folding process for TERRA25. We corroborate this hypothesis by presenting the free energy landscapes and folding pathways of four rG4 systems with varying loop length.
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Affiliation(s)
- Marijana Ugrina
- Institute of Physics, University of Augsburg, Universitätsstraße 1, 86159 Augsburg, Germany
- Department of Theoretical Biophysics, Max-Planck-Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
| | - Ines Burkhart
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Diana Müller
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Nadine Schwierz
- Institute of Physics, University of Augsburg, Universitätsstraße 1, 86159 Augsburg, Germany
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4
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Largy E, Ranz M, Gabelica V. A General Framework to Interpret Hydrogen-Deuterium Exchange Native Mass Spectrometry of G-Quadruplex DNA. J Am Chem Soc 2023; 145:26843-26857. [PMID: 38044563 DOI: 10.1021/jacs.3c09365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
G-quadruplexes (G4s) are secondary structures formed by guanine-rich oligonucleotides involved in various biological processes. However, characterizing G4s is challenging, because of their structural polymorphism. Here, we establish how hydrogen-deuterium exchange native mass spectrometry (HDX/MS) can help to characterize the G4 structures and dynamics in solution. We correlated the time range of G4 exchange to the number of guanines involved in the inner and outer tetrads. We also established relationships among exchange rates, numbers of tetrads and bound cations, and stability. The use of HDX/native MS allows for the determination of tetrads formed and assessment of G4 stability at a constant temperature. A key finding is that stable G4s exchange through local fluctuations (EX2 exchange), whereas less stable G4s also undergo exchange through partial or complete unfolding (EX1 exchange). Deconvolution of the bimodal isotope distributions resulting from EX1 exchange provides valuable insight into the kinetics of folding and unfolding processes and allows one to detect and characterize transiently unfolded intermediates, even if scarcely populated. HDX/native MS thus represents a powerful tool for a more comprehensive exploration of the folding landscapes of G4s.
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Affiliation(s)
- Eric Largy
- Université de Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
| | - Matthieu Ranz
- Université de Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
| | - Valérie Gabelica
- Université de Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
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5
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Liu LY, Ma TZ, Zeng YL, Liu W, Zhang H, Mao ZW. Organic-Platinum Hybrids for Covalent Binding of G-Quadruplexes: Structural Basis and Application to Cancer Immunotherapy. Angew Chem Int Ed Engl 2023; 62:e202305645. [PMID: 37464955 DOI: 10.1002/anie.202305645] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 06/04/2023] [Accepted: 07/17/2023] [Indexed: 07/20/2023]
Abstract
G-quadruplexes (G4s) have been revived as promising therapeutic targets with the development of immunotherapy, but the G4-mediated immune response remains unclear. We designed a novel class of G4-binding organic-platinum hybrids, L1 -cispt and L1 -transpt, with spatial matching for G4 binding and G4 DNA reactivity for binding site locking. The solution structure of L1 -transpt-MYT1L G4 demonstrated the effectiveness of the covalent binding and revealed the covalent binding-guided dynamic balance, accompanied by the destruction of the A5-T17 base pairs to achieve the covalent binding of the platinum unit to N7 of the G6 residue. Furthermore, L1 -cispt- and L1 -transpt-mediated genomic dysfunction could activate the retinoic acid-induced gene I (RIG-I) pathway and induce immunogenic cell death (ICD). The use of L1 -cispt/L1 -transpt-treated dying cells as therapeutic vaccines stimulated a robust immune response and effectively inhibited tumor growth in vivo. Our findings highlight the importance of the rational combination of specific spatial recognition and covalent locking in G4-trageting drug design and their potential in immunotherapy.
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Affiliation(s)
- Liu-Yi Liu
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, IGCME, Sun Yat-Sen University, Guangzhou, 510275, P. R. China
| | - Tian-Zhu Ma
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, IGCME, Sun Yat-Sen University, Guangzhou, 510275, P. R. China
| | - You-Liang Zeng
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, IGCME, Sun Yat-Sen University, Guangzhou, 510275, P. R. China
| | - Wenting Liu
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, IGCME, Sun Yat-Sen University, Guangzhou, 510275, P. R. China
| | - Hang Zhang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, IGCME, Sun Yat-Sen University, Guangzhou, 510275, P. R. China
| | - Zong-Wan Mao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, IGCME, Sun Yat-Sen University, Guangzhou, 510275, P. R. China
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6
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Hu W, Jing H, Fu W, Wang Z, Zhou J, Zhang N. Conversion to Trimolecular G-Quadruplex by Spontaneous Hoogsteen Pairing-Based Strand Displacement Reaction between Bimolecular G-Quadruplex and Double G-Rich Probes. J Am Chem Soc 2023; 145:18578-18590. [PMID: 37553999 DOI: 10.1021/jacs.3c05617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
Bimolecular or tetramolecular G-quadruplexes (GQs) are predominantly self-assembled by the same sequence-identical G-rich oligonucleotides and usually remain inert to the strand displacement reaction (SDR) with other short G-rich invading fragments of DNA or RNA. Appealingly, in this study, we demonstrate that a parallel homomeric bimolecular GQ target of Tub10 d(CAGGGAGGGT) as the starting reactant, although completely folded in K+ solution and sufficiently stable (melting temperature of 57.7 °C), can still spontaneously accept strand invasion by a pair of short G-rich invading probes of P1 d(TGGGA) near room temperature. The final SDR product is a novel parallel heteromeric trimolecular GQ (tri-GQ) of Tub10/2P1 reassembled between one Tub10 strand and two P1 strands. Here we present, to the best of our knowledge, the first NMR solution structure of such a discrete heteromeric tri-GQ and unveil a unique mode of two probes vs one target in mutual recognition among G-rich canonical DNA oligomers. As a model system, the short invading probe P1 can spontaneously trap G-rich target Tub10 from a Watson-Crick duplex completely hybridized between Tub10 and its fully complementary strand d(ACCCTCCCTG). The Tub10 sequence of d(CAGGGAGGGT) is a fragment from the G-rich promoter region of the human β2-tubulin gene. Our findings provide new insights into the Hoogsteen pairing-based SDR between a GQ target and double invading probes of short G-rich DNA fragments and are expected to grant access to increasingly complex architectures in GQ-based DNA nanotechnology.
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Affiliation(s)
- Wenxuan Hu
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
- University of Science and Technology of China, Hefei 230026, China
| | - Haitao Jing
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
| | - Wenqiang Fu
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
| | - Zengrong Wang
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
- University of Science and Technology of China, Hefei 230026, China
| | - Jiang Zhou
- Analytical Instrumentation Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Na Zhang
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
- Key Laboratory of Anhui Province for High Field Magnetic Resonance Imaging, Hefei 230031, China
- High Magnetic Field Laboratory of Anhui Province, Hefei 230031, China
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
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7
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Stadlbauer P, Mlýnský V, Krepl M, Šponer J. Complexity of Guanine Quadruplex Unfolding Pathways Revealed by Atomistic Pulling Simulations. J Chem Inf Model 2023; 63:4716-4731. [PMID: 37458574 PMCID: PMC10428220 DOI: 10.1021/acs.jcim.3c00171] [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: 02/02/2023] [Indexed: 08/15/2023]
Abstract
Guanine quadruplexes (GQs) are non-canonical nucleic acid structures involved in many biological processes. GQs formed in single-stranded regions often need to be unwound by cellular machinery, so their mechanochemical properties are important. Here, we performed steered molecular dynamics simulations of human telomeric GQs to study their unfolding. We examined four pulling regimes, including a very slow setup with pulling velocity and force load accessible to high-speed atomic force microscopy. We identified multiple factors affecting the unfolding mechanism, i.e.,: (i) the more the direction of force was perpendicular to the GQ channel axis (determined by GQ topology), the more the base unzipping mechanism happened, (ii) the more parallel the direction of force was, GQ opening and cross-like GQs were more likely to occur, (iii) strand slippage mechanism was possible for GQs with an all-anti pattern in a strand, and (iv) slower pulling velocity led to richer structural dynamics with sampling of more intermediates and partial refolding events. We also identified that a GQ may eventually unfold after a force drop under forces smaller than those that the GQ withstood before the drop. Finally, we found out that different unfolding intermediates could have very similar chain end-to-end distances, which reveals some limitations of structural interpretations of single-molecule spectroscopic data.
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Affiliation(s)
- Petr Stadlbauer
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Vojtěch Mlýnský
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Miroslav Krepl
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
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Shepard CP, Emehiser RG, Karmakar S, Hrdlicka PJ. Factors Impacting Invader-Mediated Recognition of Double-Stranded DNA. Molecules 2022; 28:127. [PMID: 36615321 PMCID: PMC9821881 DOI: 10.3390/molecules28010127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/16/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022] Open
Abstract
The development of chemically modified oligonucleotides enabling robust, sequence-unrestricted recognition of complementary chromosomal DNA regions has been an aspirational goal for scientists for many decades. While several groove-binding or strand-invading probes have been developed towards this end, most enable recognition of DNA only under limited conditions (e.g., homopurine or short mixed-sequence targets, low ionic strength, fully modified probe strands). Invader probes, i.e., DNA duplexes modified with +1 interstrand zippers of intercalator-functionalized nucleotides, are predisposed to recognize DNA targets due to their labile nature and high affinity towards complementary DNA. Here, we set out to gain further insight into the design parameters that impact the thermal denaturation properties and binding affinities of Invader probes. Towards this end, ten Invader probes were designed, and their biophysical properties and binding to model DNA hairpins and chromosomal DNA targets were studied. A Spearman's rank-order correlation analysis of various parameters was then performed. Densely modified Invader probes were found to result in efficient recognition of chromosomal DNA targets with excellent binding specificity in the context of denaturing or non-denaturing fluorescence in situ hybridization (FISH) experiments. The insight gained from the initial phase of this study informed subsequent probe optimization, which yielded constructs displaying improved recognition of chromosomal DNA targets. The findings from this study will facilitate the design of efficient Invader probes for applications in the life sciences.
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Lee J, Sung K, Joo SY, Jeong JH, Kim SK, Lee H. Dynamic interaction of BRCA2 with telomeric G-quadruplexes underlies telomere replication homeostasis. Nat Commun 2022; 13:3396. [PMID: 35697743 PMCID: PMC9192595 DOI: 10.1038/s41467-022-31156-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 05/31/2022] [Indexed: 12/02/2022] Open
Abstract
BRCA2-deficient cells precipitate telomere shortening upon collapse of stalled replication forks. Here, we report that the dynamic interaction between BRCA2 and telomeric G-quadruplex (G4), the non-canonical four-stranded secondary structure, underlies telomere replication homeostasis. We find that the OB-folds of BRCA2 binds to telomeric G4, which can be an obstacle during replication. We further demonstrate that BRCA2 associates with G-triplex (G3)-derived intermediates, which are likely to form during direct interconversion between parallel and non-parallel G4. Intriguingly, BRCA2 binding to G3 intermediates promoted RAD51 recruitment to the telomere G4. Furthermore, MRE11 resected G4-telomere, which was inhibited by BRCA2. Pathogenic mutations at the OB-folds abrogated the binding with telomere G4, indicating that the way BRCA2 associates with telomere is innate to its tumor suppressor activity. Collectively, we propose that BRCA2 binding to telomeric G4 remodels it and allows RAD51-mediated restart of the G4-driven replication fork stalling, simultaneously preventing MRE11-mediated breakdown of telomere. G-quadruplex (G4) can be formed in telomeric DNA. Here the authors show that BRCA2 interacts with telomere G4 structure generated during telomere replication, protecting telomere from nuclease attack.
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Affiliation(s)
- Junyeop Lee
- Department of Biological Sciences & IMBG, Seoul National University, Seoul, 08826, South Korea
| | - Keewon Sung
- Department of Chemistry, Seoul National University, Seoul, 08826, South Korea
| | - So Young Joo
- Department of Biological Sciences & IMBG, Seoul National University, Seoul, 08826, South Korea
| | - Jun-Hyeon Jeong
- Department of Biological Sciences & IMBG, Seoul National University, Seoul, 08826, South Korea
| | - Seong Keun Kim
- Department of Chemistry, Seoul National University, Seoul, 08826, South Korea.
| | - Hyunsook Lee
- Department of Biological Sciences & IMBG, Seoul National University, Seoul, 08826, South Korea.
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10
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Castelli M, Doria F, Freccero M, Colombo G, Moroni E. Studying the Dynamics of a Complex G-Quadruplex System: Insights into the Comparison of MD and NMR Data. J Chem Theory Comput 2022; 18:4515-4528. [PMID: 35666124 PMCID: PMC9281369 DOI: 10.1021/acs.jctc.2c00291] [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] [Indexed: 12/15/2022]
Abstract
![]()
Molecular dynamics
(MD) simulations are coming of age in the study
of nucleic acids, including specific tertiary structures such as G-quadruplexes.
While being precious for providing structural and dynamic information
inaccessible to experiments at the atomistic level of resolution,
MD simulations in this field may still be limited by several factors.
These include the force fields used, different models for ion parameters,
ionic strengths, and water models. We address various aspects of this
problem by analyzing and comparing microsecond-long atomistic simulations
of the G-quadruplex structure formed by the human immunodeficiency
virus long terminal repeat (HIV LTR)-III sequence for which nuclear
magnetic resonance (NMR) structures are available. The system is studied
in different conditions, systematically varying the ionic strengths,
ion numbers, and water models. We comparatively analyze the dynamic
behavior of the G-quadruplex motif in various conditions and assess
the ability of each simulation to satisfy the nuclear magnetic resonance
(NMR)-derived experimental constraints and structural parameters.
The conditions taking into account K+-ions to neutralize
the system charge, mimicking the intracellular ionic strength, and
using the four-atom water model are found to be the best in reproducing
the experimental NMR constraints and data. Our analysis also reveals
that in all of the simulated environments residues belonging to the
duplex moiety of HIV LTR-III exhibit the highest flexibility.
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Affiliation(s)
- Matteo Castelli
- Department of Chemistry, University of Pavia, V.le Taramelli 12, 27100 Pavia, Italy
| | - Filippo Doria
- Department of Chemistry, University of Pavia, V.le Taramelli 12, 27100 Pavia, Italy
| | - Mauro Freccero
- Department of Chemistry, University of Pavia, V.le Taramelli 12, 27100 Pavia, Italy
| | - Giorgio Colombo
- Department of Chemistry, University of Pavia, V.le Taramelli 12, 27100 Pavia, Italy.,Institute of Chemical Sciences and Technologies SCITEC-CNR, Via Mario Bianco, 9, 20131 Milano, Italy
| | - Elisabetta Moroni
- Institute of Chemical Sciences and Technologies SCITEC-CNR, Via Mario Bianco, 9, 20131 Milano, Italy
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Gao B, Zheng YT, Su AM, Sun B, Xi XG, Hou XM. Remodeling the conformational dynamics of I-motif DNA by helicases in ATP-independent mode at acidic environment. iScience 2022; 25:103575. [PMID: 34988409 PMCID: PMC8704484 DOI: 10.1016/j.isci.2021.103575] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 10/09/2021] [Accepted: 12/03/2021] [Indexed: 01/18/2023] Open
Abstract
I-motifs are noncanonical four-stranded DNA structures formed by C-rich sequences at acidic environment with critical biofunctions. The particular pH sensitivity has inspired the development of i-motifs as pH sensors and DNA motors in nanotechnology. However, the folding and regulation mechanisms of i-motifs remain elusive. Here, using single-molecule FRET, we first show that i-motifs are more dynamic than G4s. Impressively, i-motifs display a high diversity of six folding species with slow interconversion. Further results indicate that i-motifs can be linearized by Replication protein A. More importantly, we identified a number of helicases with high specificity to i-motifs at low pH. All these helicases directly act on and efficiently resolve i-motifs into intermediates independent of ATP, although they poorly unwind G4 or duplex at low pH. Owing to the extreme sensitivity to helicases and no need for ATP, i-motif may be applied as a probe for helicase sensing both in vitro and in vivo.
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Affiliation(s)
- Bo Gao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling 712100, China
| | - Ya-Ting Zheng
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling 712100, China
| | - Ai-Min Su
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling 712100, China
| | - Bo Sun
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xu-Guang Xi
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling 712100, China
- LBPA, Ecole Normale Supérieure Paris-Saclay, CNRS, Gif-sur-Yvette, France
| | - Xi-Miao Hou
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling 712100, China
- Corresponding author
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12
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Xi H, Jiang H, Juhas M, Zhang Y. Fluorescence detection of the human angiotensinogen protein by the G-quadruplex aptamer. Analyst 2022; 147:4040-4048. [DOI: 10.1039/d2an01057g] [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
Schematic diagram of AGT detection by a G-quadruplex based fluorescent biosensor.
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Affiliation(s)
- Hui Xi
- College of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong, 518055, China
| | - Hanlin Jiang
- College of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong, 518055, China
| | - Mario Juhas
- Medical and Molecular Microbiology Unit, Department of Medicine, Faculty of Science and Medicine, University of Fribourg, Fribourg, 1700, Switzerland
| | - Yang Zhang
- College of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong, 518055, China
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13
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Asha H, Stadlbauer P, Martínez-Fernández L, Banáš P, Šponer J, Improta R, Esposito L. Early steps of oxidative damage in DNA quadruplexes are position-dependent: Quantum mechanical and molecular dynamics analysis of human telomeric sequence containing ionized guanine. Int J Biol Macromol 2022; 194:882-894. [PMID: 34838862 DOI: 10.1016/j.ijbiomac.2021.11.143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 12/17/2022]
Abstract
Guanine radical cation (G•+) is a key intermediate in many oxidative processes occurring in nucleic acids. Here, by combining mixed Quantum Mechanical/Molecular Mechanics calculations and Molecular Dynamics (MD) simulations, we study how the structural behaviour of a tract GGG(TTAGGG)3 (hereafter Tel21) of the human telomeric sequence, folded in an antiparallel quadruple helix, changes when one of the G bases is ionized to G•+ (Tel21+). Once assessed that the electron-hole is localized on a single G, we perform MD simulations of twelve Tel21+ systems, differing in the position of G•+ in the sequence. When G•+ is located in the tetrad adjacent to the diagonal loop, we observe substantial structural rearrangements, which can decrease the electrostatic repulsion with the inner Na+ ions and increase the solvent exposed surface of G•+. Analysis of solvation patterns of G•+ provides new insights on the main reactions of G•+, i.e. the deprotonation at two different sites and hydration at the C8 atom, the first steps of the processes producing 8oxo-Guanine. We suggest the main structural determinants of the relative reactivity of each position and our conclusions, consistent with the available experimental trends, can help rationalizing the reactivity of other G-quadruplex topologies.
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Affiliation(s)
- Haritha Asha
- Istituto Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via Mezzocannone 16, 80136 Napoli, Italy
| | - Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Lara Martínez-Fernández
- Departamento de Quimica, Facultad de Ciencias and Institute for Advanced Research in Chemistry (IADCHEM), Universidad Autonoma de Madrid, Campus de Excelencia UAM-CSIC, 28049 Madrid, Spain
| | - Pavel Banáš
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic; Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, Palacký University, Křížkovského 8, 779 00 Olomouc, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.
| | - Roberto Improta
- Istituto Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via Mezzocannone 16, 80136 Napoli, Italy.
| | - Luciana Esposito
- Istituto Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via Mezzocannone 16, 80136 Napoli, Italy.
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14
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Ozcan KA, Ghaffari LT, Haeusler AR. The effects of molecular crowding and CpG hypermethylation on DNA G-quadruplexes formed by the C9orf72 nucleotide repeat expansion. Sci Rep 2021; 11:23213. [PMID: 34853325 PMCID: PMC8636472 DOI: 10.1038/s41598-021-02041-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/09/2021] [Indexed: 01/09/2023] Open
Abstract
A nucleotide repeat expansion (NRE), (G4C2)n, located in a classically noncoding region of C9orf72 (C9), is the most common genetic mutation associated with ALS/FTD. There is increasing evidence that nucleic acid structures formed by the C9-NRE may both contribute to ALS/FTD, and serve as therapeutic targets, but there is limited characterization of these nucleic acid structures under physiologically and disease relevant conditions. Here we show in vitro that the C9-NRE DNA can form both parallel and antiparallel DNA G-quadruplex (GQ) topological structures and that the structural preference of these DNA GQs can be dependent on the molecular crowding conditions. Additionally, 5-methylcytosine DNA hypermethylation, which is observed in the C9-NRE locus in some patients, has minimal effects on GQ topological preferences. Finally, molecular dynamic simulations of methylated and nonmethylated GQ structures support in vitro data showing that DNA GQ structures formed by the C9-NRE DNA are stable, with structural fluctuations limited to the cytosine-containing loop regions. These findings provide new insight into the structural polymorphic preferences and stability of DNA GQs formed by the C9-NRE in both the methylated and nonmethylated states, as well as reveal important features to guide the development of upstream therapeutic approaches to potentially attenuate C9-NRE-linked diseases.
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Affiliation(s)
- Kadir A Ozcan
- Department of Neuroscience, Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - Layla T Ghaffari
- Department of Neuroscience, Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - Aaron R Haeusler
- Department of Neuroscience, Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA. .,Department of Neuroscience, Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, 900 Walnut Street, JHN suite 410, Philadelphia, PA, 19107, USA.
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15
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Liu YC, Yang DY, Sheu SY. Insights into the free energy landscape and salt-controlled mechanism of the conformational conversions between human telomeric G-quadruplex structures. Int J Biol Macromol 2021; 191:230-242. [PMID: 34536474 DOI: 10.1016/j.ijbiomac.2021.09.057] [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] [Received: 06/29/2021] [Revised: 08/23/2021] [Accepted: 09/10/2021] [Indexed: 12/16/2022]
Abstract
G-quadruplexes have become attractive drug targets in cancer therapy. However, due to the polymorphism of G-quadruplex structures, it is difficult to experimentally verify the relevant structures of multiple intermediates and transition states in dynamic equilibrium. Hence, understanding the mechanism by which structural conversions of G-quadruplexes occur is still challenging. We conducted targeted molecular dynamics simulation with umbrella sampling to investigate how salt affects the conformational conversion of human telomeric G-quadruplex. Our results explore a unique view into the structures and energy barrier of the intermediates and transition states in the interconversion process. The pathway of G-quadruplex conformational interconversion was mapped out by a free energy landscape, consisting of branched parallel pathways with multiple energy basins. We propose a salt-controlled mechanism that as the salt concentration increases, the conformational conversion mechanism switches from multi-pathway folding to sequential folding pathways. The hybrid-I and hybrid-II structures are intermediates in the basket-propeller transformation. In high-salt solutions, the conformational conversion upon K+ binding is more feasible than upon Na+ binding. The free energy barrier for conformational conversions ranges from 1.6 to 4.6 kcal/mol. Our work will be beneficial in developing anticancer agents.
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Affiliation(s)
- Yu-Cheng Liu
- Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
| | - Dah-Yen Yang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan.
| | - Sheh-Yi Sheu
- Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei 112, Taiwan; Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei 112, Taiwan.
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16
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Cheng Y, Zhang Y, You H. Characterization of G-Quadruplexes Folding/Unfolding Dynamics and Interactions with Proteins from Single-Molecule Force Spectroscopy. Biomolecules 2021; 11:1579. [PMID: 34827577 PMCID: PMC8615981 DOI: 10.3390/biom11111579] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/16/2021] [Accepted: 10/19/2021] [Indexed: 12/19/2022] Open
Abstract
G-quadruplexes (G4s) are stable secondary nucleic acid structures that play crucial roles in many fundamental biological processes. The folding/unfolding dynamics of G4 structures are associated with the replication and transcription regulation functions of G4s. However, many DNA G4 sequences can adopt a variety of topologies and have complex folding/unfolding dynamics. Determining the dynamics of G4s and their regulation by proteins remains challenging due to the coexistence of multiple structures in a heterogeneous sample. Here, in this mini-review, we introduce the application of single-molecule force-spectroscopy methods, such as magnetic tweezers, optical tweezers, and atomic force microscopy, to characterize the polymorphism and folding/unfolding dynamics of G4s. We also briefly introduce recent studies using single-molecule force spectroscopy to study the molecular mechanisms of G4-interacting proteins.
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Affiliation(s)
| | | | - Huijuan You
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Y.C.); (Y.Z.)
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17
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Grün JT, Schwalbe H. Folding dynamics of polymorphic G-quadruplex structures. Biopolymers 2021; 113:e23477. [PMID: 34664713 DOI: 10.1002/bip.23477] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/30/2021] [Accepted: 09/30/2021] [Indexed: 12/14/2022]
Abstract
G-quadruplexes (G4), found in numerous places within the human genome, are involved in essential processes of cell regulation. Chromosomal DNA G4s are involved for example, in replication and transcription as first steps of gene expression. Hence, they influence a plethora of downstream processes. G4s possess an intricate structure that differs from canonical B-form DNA. Identical DNA G4 sequences can adopt multiple long-lived conformations, a phenomenon known as G4 polymorphism. A detailed understanding of the molecular mechanisms that drive G4 folding is essential to understand their ambivalent regulatory roles. Disentangling the inherent dynamic and polymorphic nature of G4 structures thus is key to unravel their biological functions and make them amenable as molecular targets in novel therapeutic approaches. We here review recent experimental approaches to monitor G4 folding and discuss structural aspects for possible folding pathways. Substantial progress in the understanding of G4 folding within the recent years now allows drawing comprehensive models of the complex folding energy landscape of G4s that we herein evaluate based on computational and experimental evidence.
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Affiliation(s)
- J Tassilo Grün
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-University, Frankfurt/M, Germany.,Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Frankfurt/M, Germany
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18
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Buglione E, Salerno D, Marrano CA, Cassina V, Vesco G, Nardo L, Dacasto M, Rigo R, Sissi C, Mantegazza F. Nanomechanics of G-quadruplexes within the promoter of the KIT oncogene. Nucleic Acids Res 2021; 49:4564-4573. [PMID: 33849064 PMCID: PMC8096272 DOI: 10.1093/nar/gkab079] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 01/07/2021] [Accepted: 04/09/2021] [Indexed: 12/31/2022] Open
Abstract
G-quadruplexes (G4s) are tetrahelical DNA structures stabilized by four guanines paired via Hoogsteen hydrogen bonds into quartets. While their presence within eukaryotic DNA is known to play a key role in regulatory processes, their functional mechanisms are still under investigation. In the present work, we analysed the nanomechanical properties of three G4s present within the promoter of the KIT proto-oncogene from a single-molecule point of view through the use of magnetic tweezers (MTs). The study of DNA extension fluctuations under negative supercoiling allowed us to identify a characteristic fingerprint of G4 folding. We further analysed the energetic contribution of G4 to the double-strand denaturation process in the presence of negative supercoiling, and we observed a reduction in the energy required for strands separation.
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Affiliation(s)
- Enrico Buglione
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
| | - Domenico Salerno
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
| | - Claudia Adriana Marrano
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
| | - Valeria Cassina
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
| | - Guglielmo Vesco
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
| | - Luca Nardo
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
| | - Mauro Dacasto
- Department of Comparative Biomedicine and Food Science, University of Padova, 35020 Legnaro (PD), Italy
| | - Riccardo Rigo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova (PD), Italy
| | - Claudia Sissi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova (PD), Italy.,Interdepartmental Research Center for Innovative Biotechnologies (CRIBI), University of Padova, 35121 Padova (PD), Italy
| | - Francesco Mantegazza
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
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19
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Grün JT, Blümler A, Burkhart I, Wirmer-Bartoschek J, Heckel A, Schwalbe H. Unraveling the Kinetics of Spare-Tire DNA G-Quadruplex Folding. J Am Chem Soc 2021; 143:6185-6193. [PMID: 33872503 DOI: 10.1021/jacs.1c01089] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The folding of DNA G-quadruplexes (G4) is essential to regulate expression of oncogenes and involves polymorphic long-lived intermediate states. G4 formation requires four G-tracts, but human gene-promoters often contain multiple G-tracts that act as spare-tires. These additional G-tracts are highly conserved and add multiple layers of functional complexity, as they are crucial to maintain G4 function after oxidative damage. Herein, we unravel the folding dynamics of the G4 sequence containing five G-tracts from cMYC, the major proliferation-driving oncogene. We devise a general method to induce folding at constant experimental conditions using a photochemical trapping strategy. Our data dissect the individual kinetics and thermodynamics of the spare-tire mechanism of cMYC-G4.
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Affiliation(s)
- J Tassilo Grün
- Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt am Main, Frankfurt 60323, Germany.,Center of Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Frankfurt 60323, Germany
| | - Anja Blümler
- Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt am Main, Frankfurt 60323, Germany
| | - Ines Burkhart
- Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt am Main, Frankfurt 60323, Germany.,Center of Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Frankfurt 60323, Germany
| | - Julia Wirmer-Bartoschek
- Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt am Main, Frankfurt 60323, Germany.,Center of Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Frankfurt 60323, Germany
| | - Alexander Heckel
- Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt am Main, Frankfurt 60323, Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt am Main, Frankfurt 60323, Germany.,Center of Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt am Main, Frankfurt 60323, Germany
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20
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Ye S, Chen Z, Zhang X, Li F, Guo L, Hou XM, Wu WQ, Wang J, Liu C, Zheng K, Sun B. Proximal Single-Stranded RNA Destabilizes Human Telomerase RNA G-Quadruplex and Induces Its Distinct Conformers. J Phys Chem Lett 2021; 12:3361-3366. [PMID: 33783224 DOI: 10.1021/acs.jpclett.1c00250] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Single-stranded guanine-rich RNA sequences have a propensity to fold into compact G-quadruplexes (RG4s). The conformational transitions of these molecules provide an important way to regulate their biological functions. Here, we examined the stability and conformation of an RG4-forming sequence identified near the end of human telomerase RNA. We found that a proximal single-stranded (ss) RNA significantly impairs RG4 stability at physiological K+ concentrations, resulting in a reduced RG4 rupture force of ∼ 24.4 pN and easier accessibility of the G-rich sequence. The destabilizing effect requires a minimum of six nucleotides of ssRNA and is effective at either end of RG4. Remarkably, this RG4-forming sequence, under the influence of such a proximal ssRNA, exhibits interconversions between at least three less stable RG4 conformers that might represent potential intermediates along its folding/unfolding pathway. This work provides insights into the stability and folding dynamics of RG4 that are essential for understanding its biological functions.
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Affiliation(s)
- Shasha Ye
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ziting Chen
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xia Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Fangfang Li
- State Key Laboratory of Reproductive Medicine, Center for Global Health, Nanjing Medical University, Nanjing, 211166, China
| | - Lijuan Guo
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xi-Miao Hou
- College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Wen-Qiang Wu
- Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, Kaifeng, 475001, China
| | - Jian Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Cong Liu
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Ke Zheng
- State Key Laboratory of Reproductive Medicine, Center for Global Health, Nanjing Medical University, Nanjing, 211166, China
| | - Bo Sun
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
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21
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Gao B, Hou XM. Opposite Effects of Potassium Ions on the Thermal Stability of i-Motif DNA in Different Buffer Systems. ACS OMEGA 2021; 6:8976-8985. [PMID: 33842768 PMCID: PMC8028132 DOI: 10.1021/acsomega.0c06350] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 03/11/2021] [Indexed: 05/12/2023]
Abstract
i-motifs are noncanonical DNA structures formed via the stack of intercalating hemi-protonated C+: C base pairs in C-rich DNA strands and play essential roles in the regulation of gene expression. Here, we systematically investigated the impacts of K+ on i-motif DNA folding using different buffer systems. We found that i-motif structures display very different T m values at the same pH and ion strength in different buffer systems. More importantly, K+ disrupts the i-motif formed in the MES and Bis-Tris buffer; however, K+ stabilizes the i-motif in phosphate, citrate, and sodium cacodylate buffers. Next, we selected phosphate buffer and confirmed by single-molecule fluorescence resonance energy transfer that K+ indeed has the stabilizing effect on the folding of i-motif DNA from pH 5.8 to 8.0. Nonetheless, circular dichroism spectra further indicate that the structures formed by i-motif sequences at high K+ concentrations at neutral and alkaline pH are not i-motif but other types of higher-order structures and most likely C-hairpins. We finally proposed the mechanisms of how K+ plays the opposite roles in different buffer systems. The present study may provide new insights into our understanding of the formation and stability of i-motif DNA.
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Affiliation(s)
| | - Xi-Miao Hou
- . Phone: +86 29 8708 1664. Fax: +86 29 8708 1664
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22
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Lejault P, Mitteaux J, Sperti FR, Monchaud D. How to untie G-quadruplex knots and why? Cell Chem Biol 2021; 28:436-455. [PMID: 33596431 DOI: 10.1016/j.chembiol.2021.01.015] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 12/08/2020] [Accepted: 01/20/2021] [Indexed: 12/12/2022]
Abstract
For over two decades, the prime objective of the chemical biology community studying G-quadruplexes (G4s) has been to use chemicals to interact with and stabilize G4s in cells to obtain mechanistic interpretations. This strategy has been undoubtedly successful, as demonstrated by recent advances. However, these insights have also led to a fundamental rethinking of G4-targeting strategies: due to the prevalence of G4s in the human genome, transcriptome, and ncRNAome (collectively referred to as the G4ome), and their involvement in human diseases, should we continue developing G4-stabilizing ligands or should we invest in designing molecular tools to unfold G4s? Here, we first focus on how, when, and where G4s fold in cells; then, we describe the enzymatic systems that have evolved to counteract G4 folding and how they have been used as tools to manipulate G4s in cells; finally, we present strategies currently being implemented to devise new molecular G4 unwinding agents.
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Affiliation(s)
- Pauline Lejault
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon, France
| | - Jérémie Mitteaux
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon, France
| | - Francesco Rota Sperti
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon, France
| | - David Monchaud
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon, France.
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23
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Stadlbauer P, Islam B, Otyepka M, Chen J, Monchaud D, Zhou J, Mergny JL, Šponer J. Insights into G-Quadruplex-Hemin Dynamics Using Atomistic Simulations: Implications for Reactivity and Folding. J Chem Theory Comput 2021; 17:1883-1899. [PMID: 33533244 DOI: 10.1021/acs.jctc.0c01176] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Guanine quadruplex nucleic acids (G4s) are involved in key biological processes such as replication or transcription. Beyond their biological relevance, G4s find applications as biotechnological tools since they readily bind hemin and enhance its peroxidase activity, creating a G4-DNAzyme. The biocatalytic properties of G4-DNAzymes have been thoroughly studied and used for biosensing purposes. Despite hundreds of applications and massive experimental efforts, the atomistic details of the reaction mechanism remain unclear. To help select between the different hypotheses currently under investigation, we use extended explicit-solvent molecular dynamics (MD) simulations to scrutinize the G4/hemin interaction. We find that besides the dominant conformation in which hemin is stacked atop the external G-quartets, hemin can also transiently bind to the loops and be brought to the external G-quartets through diverse delivery mechanisms. The simulations do not support the catalytic mechanism relying on a wobbling guanine. Similarly, the catalytic role of the iron-bound water molecule is not in line with our results; however, given the simulation limitations, this observation should be considered with some caution. The simulations rather suggest tentative mechanisms in which the external G-quartet itself could be responsible for the unique H2O2-promoted biocatalytic properties of the G4/hemin complexes. Once stacked atop a terminal G-quartet, hemin rotates about its vertical axis while readily sampling shifted geometries where the iron transiently contacts oxygen atoms of the adjacent G-quartet. This dynamics is not apparent from the ensemble-averaged structure. We also visualize transient interactions between the stacked hemin and the G4 loops. Finally, we investigated interactions between hemin and on-pathway folding intermediates of the parallel-stranded G4 fold. The simulations suggest that hemin drives the folding of parallel-stranded G4s from slip-stranded intermediates, acting as a G4 chaperone. Limitations of the MD technique are briefly discussed.
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Affiliation(s)
- Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Barira Islam
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Michal Otyepka
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, Palacký University, Křížkovského 8, 779 00 Olomouc, Czech Republic
| | - Jielin Chen
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - David Monchaud
- Institut de Chimie Moléculaire (ICMUB), CNRS UMR6302, UBFC, Dijon 21078, France
| | - Jun Zhou
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Jean-Louis Mergny
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.,State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210023, China.,Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau cedex, France
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
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24
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A two-quartet G-quadruplex topology of human KIT2 is conformationally selected by a perylene derivative. Biochimie 2020; 179:77-84. [DOI: 10.1016/j.biochi.2020.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 12/19/2022]
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25
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Sasaki S, Ma Y, Ishizuka T, Bao HL, Hirokawa T, Xu Y, Tera M, Nagasawa K. Linear consecutive hexaoxazoles as G4 ligands inducing chair-type anti-parallel topology of a telomeric G-quadruplex. RSC Adv 2020; 10:43319-43323. [PMID: 35519695 PMCID: PMC9058415 DOI: 10.1039/d0ra09413g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 11/23/2020] [Indexed: 12/12/2022] Open
Abstract
G-quadruplex structures (G4s) in guanine-rich regions of DNA play critical roles in various biological phenomena, including replication, translation, and gene expression. There are three types of G4 topology, i.e., parallel, anti-parallel, and hybrid, and ligands that selectively interact with or stabilize a specific topology have been extensively explored to enable studies of topology-related functions. Here, we describe the synthesis of a new series of G4 ligands based on 6LCOs (6-linear consecutive oxazoles), i.e., L2H2-2M2EA-6LCO (2), L2A2-2M2EAc-6LCO (3), and L2G2-2M2EG-6LCO (4), which bear four aminoalkyl, acetamidealkyl, and guanidinylalkyl side chains, respectively. Among them, ligand 2 stabilized telomeric G4 and induced anti-parallel topology independently of the presence of cations. The anti-parallel topology induced by 2 was identified as chair-type by means of 19F NMR spectroscopy and fluorescence experiments with 2-aminopurine-labeled DNA.
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Affiliation(s)
- Shogo Sasaki
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology 2-24-16 Naka-cho, Koganei Tokyo 184-8588 Japan
| | - Yue Ma
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology 2-24-16 Naka-cho, Koganei Tokyo 184-8588 Japan
| | - Takumi Ishizuka
- Division of Chemistry, Department of Medical Sciences, Faculty of Medicine, University of Miyazak 5200 Kihara, Kiyotake Miyazaki 889-1692 Japan
| | - Hong-Liang Bao
- Division of Chemistry, Department of Medical Sciences, Faculty of Medicine, University of Miyazak 5200 Kihara, Kiyotake Miyazaki 889-1692 Japan
| | - Takatsugu Hirokawa
- Transborder Medical Research Center, University of Tsukuba 1-1-1 Tennodai Tsukuba, 305-8575 Japan
- Division of Biomedical Science, University of Tsukuba 1-1-1 Tennodai Tsukuba, 305-8575 Japan
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology 2-4-7 Aomi, Koto-ward Tokyo 135-0064 Japan
| | - Yan Xu
- Division of Chemistry, Department of Medical Sciences, Faculty of Medicine, University of Miyazak 5200 Kihara, Kiyotake Miyazaki 889-1692 Japan
| | - Masayuki Tera
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology 2-24-16 Naka-cho, Koganei Tokyo 184-8588 Japan
| | - Kazuo Nagasawa
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology 2-24-16 Naka-cho, Koganei Tokyo 184-8588 Japan
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Bian Y, Song F, Zhang J, Yu J, Wang J, Wang W. Insights into the Kinetic Partitioning Folding Dynamics of the Human Telomeric G-Quadruplex from Molecular Simulations and Machine Learning. J Chem Theory Comput 2020; 16:5936-5947. [PMID: 32794754 DOI: 10.1021/acs.jctc.0c00340] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The human telomeric DNA G-quadruplex follows a kinetic partitioning folding mechanism. The underlying folding landscape potentially has many minima separated by high free-energy barriers. However, using current theoretical models to characterize this complex folding landscape has remained a challenging problem. In this study, by developing a hybrid atomistic structure-based model that merges structural information on the hybrid-1, hybrid-2, and chair-type G-quadruplex topologies, we investigated a kinetic partitioning folding process of human telomeric DNA involving three native folds. The model was validated as it reproduced the experimental observation that the hybrid-1 conformation is the major fold and the hybrid-2 conformation is kinetically more accessible. A three-step mechanism was revealed for the formation of the hybrid-1 conformation, while a two-step mechanism was demonstrated for the formation of hybrid-2 and chair-type conformations. Likewise, a class of state in which structures adopted inappropriate combinations of syn/anti guanine nucleotides was found to greatly slow down the folding process. In addition, by employing the XGBoost machine learning algorithm, three interatom distances and six dihedral angles were identified as essential internal coordinates to represent the low-dimensional folding landscape. The strategy of coupling the multibasin model and the machine learning algorithm may be useful to investigate the conformational dynamics of other multistate biomolecules.
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Affiliation(s)
- Yunqiang Bian
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China.,National Laboratory of Solid State Microstructure, Department of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Feng Song
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China
| | - Jian Zhang
- National Laboratory of Solid State Microstructure, Department of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jiafeng Yu
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China
| | - Jihua Wang
- Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China
| | - Wei Wang
- National Laboratory of Solid State Microstructure, Department of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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Nguyen TQN, Lim KW, Phan AT. Folding Kinetics of G-Quadruplexes: Duplex Stem Loops Drive and Accelerate G-Quadruplex Folding. J Phys Chem B 2020; 124:5122-5130. [DOI: 10.1021/acs.jpcb.0c02548] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Thi Quynh Ngoc Nguyen
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Kah Wai Lim
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Anh Tuân Phan
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore 636921, Singapore
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28
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Islam B, Stadlbauer P, Vorlíčková M, Mergny JL, Otyepka M, Šponer J. Stability of Two-Quartet G-Quadruplexes and Their Dimers in Atomistic Simulations. J Chem Theory Comput 2020; 16:3447-3463. [PMID: 32163706 DOI: 10.1021/acs.jctc.9b01068] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
G-quadruplexes (GQs) are four-stranded noncanonical DNA and RNA architectures that can be formed by guanine-rich sequences. The stability of GQs increases with the number of G-quartets, and three G-quartets generally form stable GQs. However, the stability of two-quartet GQs is an open issue. To understand the intrinsic stability of two-quartet GQ stems, we have carried out a series of unbiased molecular dynamics (MD) simulations (505 μs in total) of two- and four-quartet DNA and RNA GQs, with attention paid mainly to parallel-stranded arrangements. We used AMBER DNA parmOL15 and RNA parmOL3 force fields and tested different ion and water models. Two-quartet parallel-stranded DNA GQs unfolded in all the simulations, while the equivalent RNA GQ was stable in most of the simulations. GQs composed of two stacked units of two-quartet GQs were stable for both DNA and RNA. The simulations suggest that a minimum of three quartets are needed to form an intrinsically stable all-anti parallel-stranded DNA GQ. Parallel two-quartet DNA GQ may exist if substantially stabilized by another molecule or structural element, including multimerization. On the other hand, we predict that isolated RNA two-quartet parallel GQs may form, albeit being weakly stable. We also show that ionic parameters and water models should be chosen with caution because some parameter combinations can cause spurious instability of GQ stems. Some in-so-far unnoticed limitations of force-field description of multiple ions inside the GQs are discussed, which compromise the capability of simulations to fully capture the effect of increase in the number of quartets on the GQ stability.
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Affiliation(s)
- Barira Islam
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Michaela Vorlíčková
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Jean-Louis Mergny
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Michal Otyepka
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic.,Department of Physical Chemistry, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
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29
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Chow EYC, Lyu K, Kwok CK, Chan TF. rG4-seeker enables high-confidence identification of novel and non-canonical rG4 motifs from rG4-seq experiments. RNA Biol 2020; 17:903-917. [PMID: 32338139 PMCID: PMC7577744 DOI: 10.1080/15476286.2020.1740470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We recently developed the rG4-seq method to detect and map in vitro RNA G-quadruplex (rG4s) structures on a transcriptome-wide scale. rG4-seq of purified human HeLa RNA has revealed many non-canonical rG4s and the effects adjacent sequences have on rG4 formation. In this study, we aimed to improve the outcomes and false-positive discrimination in rG4-seq experiments using a bioinformatic approach. By establishing connections between rG4-seq library preparation chemistry and the underlying properties of sequencing data, we identified how to mitigate indigenous sampling errors and background noise in rG4-seq. We applied these findings to develop a novel bioinformatics pipeline named rG4-seeker (https://github.com/TF-Chan-Lab/rG4-seeker), which uses tailored noise models to autonomously assess and optimize rG4 detections in a replicate-independent manner. Compared with previous methods, rG4-seeker exhibited better false-positive discrimination and improved sensitivity for non-canonical rG4s. Using rG4-seeker, we identified novel features in rG4 formation that were missed previously. rG4-seeker provides a reliable and sensitive approach for rG4-seq investigations, laying the foundations for further elucidation of rG4 biology.
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Affiliation(s)
- Eugene Yui-Ching Chow
- School of Life Sciences, and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong , Shatin, Hong Kong SAR, China
| | - Kaixin Lyu
- Department of Chemistry, City University of Hong Kong , Kowloon Tong, Hong Kong SAR, China
| | - Chun Kit Kwok
- Department of Chemistry, City University of Hong Kong , Kowloon Tong, Hong Kong SAR, China.,Shenzhen Research Institute of City University of Hong Kong , Shenzhen, China
| | - Ting-Fung Chan
- School of Life Sciences, and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong , Shatin, Hong Kong SAR, China
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30
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Pal S, Paul S. Understanding The Role of Reline, a Natural DES, on Temperature-Induced Conformational Changes of C-Kit G-Quadruplex DNA: A Molecular Dynamics Study. J Phys Chem B 2020; 124:3123-3136. [PMID: 32207949 DOI: 10.1021/acs.jpcb.0c00644] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The noncanonical guanine-rich DNAs have drawn particular attention to the scientific world due to their controllable diverse and polymorphic structures. Apart from biological and medical significance, G-quadruplex DNAs are widely used in various fields such as nanotechnology, nanomachine, biosensors, and biocatalyst. So far, the applications of the G-quadruplex DNA are mainly limited in the water medium. Recently, a new generation of solvent named deep eutectic solvent (DES) has become very popular and has been widely used as a reaction medium of biocatalytic reactions and long-term storage medium for nucleic acids, even at high temperature. Hence, it is essential to understand the role of DES on temperature-induced conformational changes of a G-quadruplex DNA. In this research work, we have explored the temperature-mediated conformational dynamics of c-kit oncogene promoter G-quadruplex DNA in reline medium in the temperature range of 300-500 K, using a total of 10 μs unbiased all-atom molecular dynamics simulation. Here, from RMSD, RMSF, Rg and principal component analyses, we notice that the c-kit G-quadruplex DNA is stable up to 450 K in reline medium. However, it unfolds in water medium at 450 K. It is found that the hydrogen bonding interactions between c-kit G-quadruplex DNA and reline play a key role in the stabilization of the G-quadruplex DNA even at high temperature. Furthermore, in this work we have observed a very interesting and distinctive phenomenon of the central cation of the G-quadruplex DNA. Its position was seen to fluctuate between the two tetrad cores, that is, the region between tetrad-1 and tetrad-2 and that between tetrad-2 and tetrad-3 and vice versa at 450 and 500 K in reline medium which is absent in water medium at 450 K. Moreover, the rate of its oscillation is increased when temperature is increased.
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Affiliation(s)
- Saikat Pal
- Department of Chemistry, Indian Institute of Technology, Guwahati Assam, India, 781039
| | - Sandip Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati Assam, India, 781039
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31
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Frelih T, Wang B, Plavec J, Šket P. Pre-folded structures govern folding pathways of human telomeric G-quadruplexes. Nucleic Acids Res 2020; 48:2189-2197. [PMID: 31950178 PMCID: PMC7038944 DOI: 10.1093/nar/gkz1235] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 12/12/2019] [Accepted: 12/31/2019] [Indexed: 01/12/2023] Open
Abstract
Understanding the mechanism by which biological macromolecules fold into their functional native conformations represents a problem of fundamental interest. DNA oligonucleotides derived from human telomeric repeat d[TAGGG(TTAGGG)3] and d[TAGGG(TTAGGG)3TT] fold into G-quadruplexes through diverse steps. Varying the pH and temperature by the use of nuclear magnetic resonance and other methods enabled detection of pre-folded structures that exist in solution before completely formed G-quadruplexes upon addition of cations. Pre-folded structures are in general hard to detect, however their knowledge is crucial to set up folding pathways into final structure since they are believed to be a starting point. Unexpectedly well-defined pre-folded structures composed of base triples for both oligonucleotides were detected at certain pH and temperature. These kinds of structures were up to now only hypothesized as intermediates in the folding process. All revealed pre-folded structures irrespective of the pH and temperature exhibited one common structural feature that could govern folding process.
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Affiliation(s)
- Tjaša Frelih
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana 1000, Slovenia
| | - Baifan Wang
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana 1000, Slovenia
| | - Janez Plavec
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana 1000, Slovenia
- EN-FIST Center of Excellence, Ljubljana 1000, Slovenia
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana 1000, Slovenia
- Correspondence may also be addressed to Janez Plavec. Tel: +386 1 476 0353; Fax: +386 1 476 0300;
| | - Primož Šket
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana 1000, Slovenia
- To whom correspondence should be addressed. Tel: +386 1 476 0223; Fax: +386 1 476 0300;
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32
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Molecular dynamics simulations of G-quadruplexes: The basic principles and their application to folding and ligand binding. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2020. [DOI: 10.1016/bs.armc.2020.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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