1
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Ding E, Chaudhury SN, Prajapati JD, Onuchic JN, Sanbonmatsu KY. Magnesium ions mitigate metastable states in the regulatory landscape of mRNA elements. RNA (NEW YORK, N.Y.) 2024; 30:992-1010. [PMID: 38777381 PMCID: PMC11251524 DOI: 10.1261/rna.079767.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 03/27/2024] [Indexed: 05/25/2024]
Abstract
Residing in the 5' untranslated region of the mRNA, the 2'-deoxyguanosine (2'-dG) riboswitch mRNA element adopts an alternative structure upon binding of the 2'-dG molecule, which terminates transcription. RNA conformations are generally strongly affected by positively charged metal ions (especially Mg2+). We have quantitatively explored the combined effect of ligand (2'-dG) and Mg2+ binding on the energy landscape of the aptamer domain of the 2'-dG riboswitch with both explicit solvent all-atom molecular dynamics simulations (99 μsec aggregate sampling for the study) and selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) experiments. We show that both ligand and Mg2+ are required for the stabilization of the aptamer domain; however, the two factors act with different modalities. The addition of Mg2+ remodels the energy landscape and reduces its frustration by the formation of additional contacts. In contrast, the binding of 2'-dG eliminates the metastable states by nucleating a compact core for the aptamer domain. Mg2+ ions and ligand binding are required to stabilize the least stable helix, P1 (which needs to unfold to activate the transcription platform), and the riboswitch core formed by the backbone of the P2 and P3 helices. Mg2+ and ligand also facilitate a more compact structure in the three-way junction region.
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Affiliation(s)
- Erdong Ding
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, USA
- Department of Chemistry, Rice University, Houston, Texas 77005, USA
| | - Susmit Narayan Chaudhury
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | | | - José N Onuchic
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, USA
- Department of Chemistry, Rice University, Houston, Texas 77005, USA
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
- Department of Biosciences, Rice University, Houston, Texas 77005, USA
| | - Karissa Y Sanbonmatsu
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
- New Mexico Consortium, Los Alamos, New Mexico 87544, USA
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2
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Gibaut QR, Bush JA, Tong Y, Baisden JT, Taghavi A, Olafson H, Yao X, Childs-Disney JL, Wang ET, Disney MD. Transcriptome-Wide Studies of RNA-Targeted Small Molecules Provide a Simple and Selective r(CUG) exp Degrader in Myotonic Dystrophy. ACS CENTRAL SCIENCE 2023; 9:1342-1353. [PMID: 37521782 PMCID: PMC10375898 DOI: 10.1021/acscentsci.2c01223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Indexed: 08/01/2023]
Abstract
Myotonic dystrophy type 1 (DM1) is caused by a highly structured RNA repeat expansion, r(CUG)exp, harbored in the 3' untranslated region (3' UTR) of dystrophia myotonica protein kinase (DMPK) mRNA and drives disease through a gain-of-function mechanism. A panel of low-molecular-weight fragments capable of reacting with RNA upon UV irradiation was studied for cross-linking to r(CUG)expin vitro, affording perimidin-2-amine diazirine (1) that bound to r(CUG)exp. The interactions between the small molecule and RNA were further studied by nuclear magnetic resonance (NMR) spectroscopy and molecular modeling. Binding of 1 in DM1 myotubes was profiled transcriptome-wide, identifying 12 transcripts including DMPK that were bound by 1. Augmenting the functionality of 1 with cleaving capability created a chimeric degrader that specifically targets r(CUG)exp for elimination. The degrader broadly improved DM1-associated defects as assessed by RNA-seq, while having limited effects on healthy myotubes. This study (i) provides a platform to investigate molecular recognition of ligands directly in disease-affected cells; (ii) illustrates that RNA degraders can be more specific than the binders from which they are derived; and (iii) suggests that repeating transcripts can be selectively degraded due to the presence of multiple ligand binding sites.
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Affiliation(s)
- Quentin
M. R. Gibaut
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Jessica A. Bush
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Yuquan Tong
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Jared T. Baisden
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Amirhossein Taghavi
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Hailey Olafson
- Center
for NeuroGenetics, University of Florida, Gainesville, Florida 32610, United States
- Department
of Molecular Genetics & Microbiology, College of Medicine, University of Florida, Gainesville, Florida 32610, United States
| | - Xiyuan Yao
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Jessica L. Childs-Disney
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Eric T. Wang
- Center
for NeuroGenetics, University of Florida, Gainesville, Florida 32610, United States
- Department
of Molecular Genetics & Microbiology, College of Medicine, University of Florida, Gainesville, Florida 32610, United States
| | - Matthew D. Disney
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
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3
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Heel SV, Bartosik K, Juen F, Kreutz C, Micura R, Breuker K. Native Top-Down Mass Spectrometry Uncovers Two Distinct Binding Motifs of a Functional Neomycin-Sensing Riboswitch Aptamer. J Am Chem Soc 2023. [PMID: 37420313 PMCID: PMC10360057 DOI: 10.1021/jacs.3c02774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2023]
Abstract
Understanding how ligands bind to ribonucleic acids (RNA) is important for understanding RNA recognition in biological processes and drug development. Here, we have studied neomycin B binding to neomycin-sensing riboswitch aptamer constructs by native top-down mass spectrometry (MS) using electrospray ionization (ESI) and collisionally activated dissociation (CAD). Our MS data for a 27 nt aptamer construct reveal the binding site and ligand interactions, in excellent agreement with the structure derived from nuclear magnetic resonance (NMR) studies. Strikingly, for an extended 40 nt aptamer construct, which represents the sequence with the highest regulatory factor for riboswitch function, we identified two binding motifs for neomycin B binding, one corresponding to the bulge-loop motif of the 27 nt construct and the other one in the minor groove of the lower stem, which according to the MS data are equally populated. By replacing a noncanonical with a canonical base pair in the lower stem of the 40 nt aptamer, we can reduce binding to the minor groove motif from ∼50 to ∼30%. Conversely, the introduction of a CUG/CUG motif in the lower stem shifts the binding equilibrium in favor of minor groove binding. The MS data reveal site-specific and stoichiometry-resolved information on aminoglycoside binding to RNA that is not directly accessible by other methods and underscore the role of noncanonical base pairs in RNA recognition by aminoglycosides.
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Affiliation(s)
- Sarah Viola Heel
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Karolina Bartosik
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Fabian Juen
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Christoph Kreutz
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Kathrin Breuker
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
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4
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Wang J, Sha CM, Dokholyan NV. Combining Experimental Restraints and RNA 3D Structure Prediction in RNA Nanotechnology. Methods Mol Biol 2023; 2709:51-64. [PMID: 37572272 PMCID: PMC10680996 DOI: 10.1007/978-1-0716-3417-2_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/14/2023]
Abstract
Precise RNA tertiary structure prediction can aid in the design of RNA nanoparticles. However, most existing RNA tertiary structure prediction methods are limited to small RNAs with relatively simple secondary structures. Large RNA molecules usually have complex secondary structures, including multibranched loops and pseudoknots, allowing for highly flexible RNA geometries and multiple stable states. Various experiments and bioinformatics analyses can often provide information about the distance between atoms (or residues) in RNA, which can be used to guide the prediction of RNA tertiary structure. In this chapter, we will introduce a platform, iFoldNMR, that can incorporate non-exchangeable imino protons resonance data from NMR as restraints for RNA 3D structure prediction. We also introduce an algorithm, DVASS, which optimizes distance restraints for better RNA 3D structure prediction.
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Affiliation(s)
- Jian Wang
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, USA
| | - Congzhou M Sha
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, USA
- Department of Engineering Science and Mechanics, Penn State University, State College, PA, USA
| | - Nikolay V Dokholyan
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, USA.
- Department of Engineering Science and Mechanics, Penn State University, State College, PA, USA.
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, PA, USA.
- Department of Chemistry, Penn State University, State College, PA, USA.
- Department of Biomedical Engineering, Penn State University, State College, PA, USA.
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5
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Zhao S, Li X, Wen Z, Zou M, Yu G, Liu X, Mao J, Zhang L, Xue Y, Fu R, Wang S. Dynamics of base pairs with low stability in RNA by solid-state nuclear magnetic resonance exchange spectroscopy. iScience 2022; 25:105322. [DOI: 10.1016/j.isci.2022.105322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 09/07/2022] [Accepted: 10/07/2022] [Indexed: 11/28/2022] Open
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6
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Bramham JE, Zalar M, Golovanov AP. Controlled release and characterisation of photocaged molecules using in situ LED illumination in solution NMR spectroscopy. Chem Commun (Camb) 2022; 58:11973-11976. [DOI: 10.1039/d2cc04731d] [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
We demonstrate that photo-uncaging reactions triggered by LED illumination can be conveniently monitored in situ by solution NMR, offering new ways to characterise and optimise photocages.
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Affiliation(s)
- Jack E. Bramham
- Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, Manchester, M13 9PL, UK
| | - Matja Zalar
- Department of Chemical Engineering, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, Manchester, M13 9PL, UK
| | - Alexander P. Golovanov
- Department of Chemistry, School of Natural Sciences, Faculty of Science and Engineering, The University of Manchester, Manchester, M13 9PL, UK
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7
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A transient conformation facilitates ligand binding to the adenine riboswitch. iScience 2021; 24:103512. [PMID: 34927032 PMCID: PMC8652005 DOI: 10.1016/j.isci.2021.103512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 10/14/2021] [Accepted: 11/22/2021] [Indexed: 11/29/2022] Open
Abstract
RNAs adopt various conformations to perform different functions in cells. Incapable of acquiring intermediates, the key initiations of ligand recognition in the adenine riboswitch have not been characterized. In this work, stopped-flow fluorescence was used to track structural switches in the full-length adenine riboswitch in real time. We used PLOR (position-selective labeling of RNA) to incorporate fluorophores into desired positions in the RNA. The switching sequence P1 responded to adenine more rapidly than helix P4 and the binding pocket, followed by stabilization of the binding pocket, P4, and annealing of P1. Moreover, a transient intermediate consisting of an unwound P1 was detected during adenine binding. These events were observed in both the WT riboswitch and a functional mutant. The findings provide insight into the conformational changes of the riboswitch RNA triggered by a ligand. Real-time tracking of the adenine riboswitch at nucleotide resolution A transient conformation with unwound P1 is identified in the adenine riboswitch Helix P1 responds to ligand quicker than the binding pocket or expression platform
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8
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Paululat T, Rabe M, Berdnikova DV. Modification of an NMR probe for monitoring of photoreactions. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 327:106990. [PMID: 33932912 DOI: 10.1016/j.jmr.2021.106990] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 06/12/2023]
Abstract
We describe a modified NMR probe for the in situ irradiation studies of photochemical reactions in solution-state NMR. To build up this setup, we designed an irradiation insert that brings eight light-emitting diodes (LEDs) into the NMR probe in the immediate proximity of the sample. The inserts with LEDs of different wavelengths are easily exchangeable within minutes. A tunable power supply allows to adjust the light intensity to optimize the irradiation conditions.
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Affiliation(s)
- Thomas Paululat
- Dr. Daria V. Berdnikova, Universität Siegen, Organische Chemie II, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany.
| | - Markus Rabe
- Universität Siegen, Werkstatt AR, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany.
| | - Daria V Berdnikova
- Dr. Daria V. Berdnikova, Universität Siegen, Organische Chemie II, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany.
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9
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Kaiser C, Schneider J, Groher F, Suess B, Wachtveitl J. What defines a synthetic riboswitch? - Conformational dynamics of ciprofloxacin aptamers with similar binding affinities but varying regulatory potentials. Nucleic Acids Res 2021; 49:3661-3671. [PMID: 33772594 PMCID: PMC8053125 DOI: 10.1093/nar/gkab166] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 02/25/2021] [Accepted: 03/23/2021] [Indexed: 11/16/2022] Open
Abstract
Among the many in vitro-selected aptamers derived from SELEX protocols, only a small fraction has the potential to be applied for synthetic riboswitch engineering. Here, we present a comparative study of the binding properties of three different aptamers that bind to ciprofloxacin with similar KD values, yet only two of them can be applied as riboswitches. We used the inherent ligand fluorescence that is quenched upon binding as the reporter signal in fluorescence titration and in time-resolved stopped-flow experiments. Thus, we were able to demonstrate differences in the binding kinetics of regulating and non-regulating aptamers. All aptamers studied underwent a two-step binding mechanism that suggests an initial association step followed by a reorganization of the aptamer to accommodate the ligand. We show that increasing regulatory potential is correlated with a decreasing back-reaction rate of the second binding step, thus resulting in a virtually irreversible last binding step of regulating aptamers. We suggest that a highly favoured structural adaption of the RNA to the ligand during the final binding step is essential for turning an aptamer into a riboswitch. In addition, our results provide an explanation for the fact that so few aptamers with regulating capacity have been found to date. Based on our data, we propose an adjustment of the selection protocol for efficient riboswitch detection.
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Affiliation(s)
- Christoph Kaiser
- Institute for Physical and Theoretical Chemistry, Goethe-Universität Frankfurt, Max-von-Laue-Straße 8, D-60438 Frankfurt am Main, Germany
| | - Jeannine Schneider
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstraße 10, D-64287 Darmstadt, Germany
| | - Florian Groher
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstraße 10, D-64287 Darmstadt, Germany
| | - Beatrix Suess
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstraße 10, D-64287 Darmstadt, Germany.,Centre for Synthetic Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Josef Wachtveitl
- Institute for Physical and Theoretical Chemistry, Goethe-Universität Frankfurt, Max-von-Laue-Straße 8, D-60438 Frankfurt am Main, Germany
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10
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Pintér G, Hohmann K, Grün J, Wirmer-Bartoschek J, Glaubitz C, Fürtig B, Schwalbe H. Real-time nuclear magnetic resonance spectroscopy in the study of biomolecular kinetics and dynamics. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2021; 2:291-320. [PMID: 37904763 PMCID: PMC10539803 DOI: 10.5194/mr-2-291-2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 04/07/2021] [Indexed: 11/01/2023]
Abstract
The review describes the application of nuclear magnetic resonance (NMR) spectroscopy to study kinetics of folding, refolding and aggregation of proteins, RNA and DNA. Time-resolved NMR experiments can be conducted in a reversible or an irreversible manner. In particular, irreversible folding experiments pose large requirements for (i) signal-to-noise due to the time limitations and (ii) synchronising of the refolding steps. Thus, this contribution discusses the application of methods for signal-to-noise increases, including dynamic nuclear polarisation, hyperpolarisation and photo-CIDNP for the study of time-resolved NMR studies. Further, methods are reviewed ranging from pressure and temperature jump, light induction to rapid mixing to induce rapidly non-equilibrium conditions required to initiate folding.
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Affiliation(s)
- György Pintér
- Institute for Organic Chemistry and Chemical Biology, Center for
Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang
Goethe-Universität Frankfurt, Frankfurt 60438, Germany
| | - Katharina F. Hohmann
- Institute for Organic Chemistry and Chemical Biology, Center for
Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang
Goethe-Universität Frankfurt, Frankfurt 60438, Germany
| | - J. Tassilo Grün
- Institute for Organic Chemistry and Chemical Biology, Center for
Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang
Goethe-Universität Frankfurt, Frankfurt 60438, Germany
| | - Julia Wirmer-Bartoschek
- Institute for Organic Chemistry and Chemical Biology, Center for
Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang
Goethe-Universität Frankfurt, Frankfurt 60438, Germany
| | - Clemens Glaubitz
- Institute for Biophysical Chemistry, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-Universität Frankfurt, Frankfurt 60438, Germany
| | - Boris Fürtig
- Institute for Organic Chemistry and Chemical Biology, Center for
Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang
Goethe-Universität Frankfurt, Frankfurt 60438, Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for
Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang
Goethe-Universität Frankfurt, Frankfurt 60438, Germany
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11
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Kim J, Novakovic M, Jayanthi S, Lupulescu A, Kupce E, Grün JT, Mertinkus K, Oxenfarth A, Richter C, Schnieders R, Wirmer-Bartoschek J, Schwalbe H, Frydman L. 3D Heteronuclear Magnetization Transfers for the Establishment of Secondary Structures in SARS-CoV-2-Derived RNAs. J Am Chem Soc 2021; 143:4942-4948. [PMID: 33783202 PMCID: PMC8154514 DOI: 10.1021/jacs.1c01914] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Multidimensional NOESY experiments targeting correlations between exchangeable imino and amino protons provide valuable information about base pairing in nucleic acids. It has been recently shown that the sensitivity of homonuclear correlations involving RNA's labile imino protons can be significantly enhanced, by exploiting the repolarization brought about by solvent exchanges. Homonuclear correlations, however, are of limited spectral resolution, and usually incapable of tackling relatively large homopolymers with repeating structures like RNAs. This study presents a heteronuclear-resolved version of those NOESY experiments, in which magnetization transfers between the aqueous solvent and the nucleic acid protons are controlled by selecting specific chemical shift combinations of a coupled 1H-15N spin pair. This selective control effectively leads to a pseudo-3D version of HSQC-NOESY, but with cross-peaks enhanced by ∼2-5× as compared with conventional 2D NOESY counterparts. The enhanced signal sensitivity as well as access to both 15N-1H and 1H-1H NOESY dimensions can greatly facilitate RNA assignments and secondary structure determinations, as demonstrated here with the analysis of genome fragments derived from the SARS-CoV-2 virus.
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Affiliation(s)
- Jihyun Kim
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Mihajlo Novakovic
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Sundaresan Jayanthi
- Department of Physics, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695 547, Kerala, India
| | - Adonis Lupulescu
- Aleea Nicolae Titulescu nr. 8, Turda, 407405 Judeţul Cluj, Romania
| | - Eriks Kupce
- Bruker Ltd, Banner Lane, Coventry CV4 9GH, United Kingdom
| | - J Tassilo Grün
- Institute of Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, D-60438 Frankfurt/Main, Germany
| | - Klara Mertinkus
- Institute of Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, D-60438 Frankfurt/Main, Germany
| | - Andreas Oxenfarth
- Institute of Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, D-60438 Frankfurt/Main, Germany
| | - Christian Richter
- Institute of Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, D-60438 Frankfurt/Main, Germany
| | - Robbin Schnieders
- Institute of Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, D-60438 Frankfurt/Main, Germany
| | - Julia Wirmer-Bartoschek
- Institute of Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, D-60438 Frankfurt/Main, Germany
| | - Harald Schwalbe
- Institute of Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, D-60438 Frankfurt/Main, Germany
| | - Lucio Frydman
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
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12
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San Emeterio J, Pollack L. Visualizing a viral genome with contrast variation small angle X-ray scattering. J Biol Chem 2020; 295:15923-15932. [PMID: 32913117 PMCID: PMC7681021 DOI: 10.1074/jbc.ra120.013961] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 09/04/2020] [Indexed: 01/14/2023] Open
Abstract
Despite the threat to human health posed by some single-stranded RNA viruses, little is understood about their assembly. The goal of this work is to introduce a new tool for watching an RNA genome direct its own packaging and encapsidation by proteins. Contrast variation small-angle X-ray scattering (CV-SAXS) is a powerful tool with the potential to monitor the changing structure of a viral RNA through this assembly process. The proteins, though present, do not contribute to the measured signal. As a first step in assessing the feasibility of viral genome studies, the structure of encapsidated MS2 RNA was exclusively detected with CV-SAXS and compared with a structure derived from asymmetric cryo-EM reconstructions. Additional comparisons with free RNA highlight the significant structural rearrangements induced by capsid proteins and invite the application of time-resolved CV-SAXS to reveal interactions that result in efficient viral assembly.
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Affiliation(s)
- Josue San Emeterio
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York, USA
| | - Lois Pollack
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York, USA.
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13
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Binas O, Schamber T, Schwalbe H. The conformational landscape of transcription intermediates involved in the regulation of the ZMP-sensing riboswitch from Thermosinus carboxydivorans. Nucleic Acids Res 2020; 48:6970-6979. [PMID: 32479610 PMCID: PMC7337938 DOI: 10.1093/nar/gkaa427] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/03/2020] [Accepted: 05/29/2020] [Indexed: 01/30/2023] Open
Abstract
Recently, prokaryotic riboswitches have been identified that regulate transcription in response to change of the concentration of secondary messengers. The ZMP (5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR))-sensing riboswitch from Thermosinus carboxydivorans is a transcriptional ON-switch that is involved in purine and carbon-1 metabolic cycles. Its aptamer domain includes the pfl motif, which features a pseudoknot, impeding rho-independent terminator formation upon stabilization by ZMP interaction. We herein investigate the conformational landscape of transcriptional intermediates including the expression platform of this riboswitch and characterize the formation and unfolding of the important pseudoknot structure in the context of increasing length of RNA transcripts. NMR spectroscopic data show that even surprisingly short pre-terminator stems are able to disrupt ligand binding and thus metabolite sensing. We further show that the pseudoknot structure, a prerequisite for ligand binding, is preformed in transcription intermediates up to a certain length. Our results describe the conformational changes of 13 transcription intermediates of increasing length to delineate the change in structure as mRNA is elongated during transcription. We thus determine the length of the key transcription intermediate to which addition of a single nucleotide leads to a drastic drop in ZMP affinity.
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Affiliation(s)
- Oliver Binas
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Germany
| | - Tatjana Schamber
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Germany
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14
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Skubi KL, Swords WB, Hofstetter H, Yoon TP. LED-NMR Monitoring of an Enantioselective Catalytic [2+2] Photocycloaddition. CHEMPHOTOCHEM 2020; 4:685-690. [PMID: 34532566 PMCID: PMC8443221 DOI: 10.1002/cptc.202000094] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Indexed: 01/08/2023]
Abstract
We report that an NMR spectrometer equipped with a high-power LED light source can be used to study a fast enantioselective photocatalytic [2+2] cycloaddition. While traditional ex situ applications of NMR provide considerable information on reaction mechanisms, they are often ineffective for observing fast reactions. Recently, motivated by renewed interest in organic photochemistry, several approaches have been reported for in situ monitoring of photochemical reactions. These previously disclosed methods, however, have rarely been applied to rapid (<5 min) photochemical reactions. Furthermore, these approaches have not previously been used to interrogate the mechanisms of photocatalytic energy-transfer reactions. In the present work, we describe our experimental setup and demonstrate its utility by determining a phenomenological rate law for a model photocatalytic energy-transfer cycloaddition reaction.
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Affiliation(s)
- Kazimer L Skubi
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI (USA)
- Department of Chemistry, Skidmore College, 815 North Broadway, Saratoga Springs, NY (USA)
| | - Wesley B Swords
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI (USA)
| | - Heike Hofstetter
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI (USA)
| | - Tehshik P Yoon
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI (USA)
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15
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Light-controlled twister ribozyme with single-molecule detection resolves RNA function in time and space. Proc Natl Acad Sci U S A 2020; 117:12080-12086. [PMID: 32430319 DOI: 10.1073/pnas.2003425117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Small ribozymes such as Oryza sativa twister spontaneously cleave their own RNA when the ribozyme folds into its active conformation. The coupling between twister folding and self-cleavage has been difficult to study, however, because the active ribozyme rapidly converts to product. Here, we describe the synthesis of a photocaged nucleotide that releases guanosine within microseconds upon photosolvolysis with blue light. Application of this tool to O. sativa twister achieved the spatial (75 µm) and temporal (≤30 ms) control required to resolve folding and self-cleavage events when combined with single-molecule fluorescence detection of the ribozyme folding pathway. Real-time observation of single ribozymes after photo-deprotection showed that the precleaved folded state is unstable and quickly unfolds if the RNA does not react. Kinetic analysis showed that Mg2+ and Mn2+ ions increase ribozyme efficiency by making transitions to the high energy active conformation more probable, rather than by stabilizing the folded ground state or the cleaved product. This tool for light-controlled single RNA folding should offer precise and rapid control of other nucleic acid systems.
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16
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Hu G, Li H, Xu S, Wang J. Ligand Binding Mechanism and Its Relationship with Conformational Changes in Adenine Riboswitch. Int J Mol Sci 2020; 21:ijms21061926. [PMID: 32168940 PMCID: PMC7139962 DOI: 10.3390/ijms21061926] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/01/2020] [Accepted: 03/09/2020] [Indexed: 12/13/2022] Open
Abstract
Riboswitches are naturally occurring RNA aptamers that control the expression of essential bacterial genes by binding to specific small molecules. The binding with both high affinity and specificity induces conformational changes. Thus, riboswitches were proposed as a possible molecular target for developing antibiotics and chemical tools. The adenine riboswitch can bind not only to purine analogues but also to pyrimidine analogues. Here, long molecular dynamics (MD) simulations and molecular mechanics Poisson–Boltzmann surface area (MM-PBSA) computational methodologies were carried out to show the differences in the binding model and the conformational changes upon five ligands binding. The binding free energies of the guanine riboswitch aptamer with C74U mutation complexes were compared to the binding free energies of the adenine riboswitch (AR) aptamer complexes. The calculated results are in agreement with the experimental data. The differences for the same ligand binding to two different aptamers are related to the electrostatic contribution. Binding dynamical analysis suggests a flexible binding pocket for the pyrimidine ligand in comparison with the purine ligand. The 18 μs of MD simulations in total indicate that both ligand-unbound and ligand-bound aptamers transfer their conformation between open and closed states. The ligand binding obviously affects the conformational change. The conformational states of the aptamer are associated with the distance between the mass center of two key nucleotides (U51 and A52) and the mass center of the other two key nucleotides (C74 and C75). The results suggest that the dynamical character of the binding pocket would affect its biofunction. To design new ligands of the adenine riboswitch, it is recommended to consider the binding affinities of the ligand and the conformational change of the ligand binding pocket.
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Affiliation(s)
- Guodong Hu
- Correspondence: (G.H.); (J.W.); Tel.: +86-534-8987536 (G.H.); +86-534-8985933 (J.W.)
| | | | | | - Jihua Wang
- Correspondence: (G.H.); (J.W.); Tel.: +86-534-8987536 (G.H.); +86-534-8985933 (J.W.)
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17
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Fürtig B, Oberhauser EM, Zetzsche H, Klötzner DP, Heckel A, Schwalbe H. Refolding through a Linear Transition State Enables Fast Temperature Adaptation of a Translational Riboswitch. Biochemistry 2020; 59:1081-1086. [PMID: 32134253 DOI: 10.1021/acs.biochem.9b01044] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The adenine-sensing riboswitch from the Gram-negative bacterium Vibrio vulnificus is an RNA-based gene regulatory element that acts in response to both its cognate low-molecular weight ligand and temperature. The combined sensitivity to environmental temperature and ligand concentration is maintained by an equilibrium of three distinct conformations involving two ligand-free states and one ligand-bound state. The key structural element that undergoes refolding in the ligand-free states comprises a 35-nucleotide temperature response module. Here, we present the structural characterization of this temperature response module. We employ high-resolution NMR spectroscopy and photocaged RNAs as molecular probes to decipher the kinetic and thermodynamic framework of the secondary structure transition in the apo state of the riboswitch. We propose a model for the transition state adopted during the thermal refolding of the temperature response module that connects two mutually exclusive long-lived and stable conformational states. This transition state is characterized by a comparatively low free activation enthalpy. A pseudoknot conformation in the transition state, as commonly seen in RNA refolding, is therefore unlikely. More likely, the transition state of the adenine-sensing riboswitch temperature response module features a linear conformation.
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Affiliation(s)
- Boris Fürtig
- Johann Wolfgang Goethe University, Institute of Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Max von Laue Strasse 7, 60438 Frankfurt/Main, Germany
| | - Eva Marie Oberhauser
- Institute of Organic Chemistry and Chemical Biology, Max von Laue Strasse 7, 60438 Frankfurt/Main, Germany
| | - Heidi Zetzsche
- Johann Wolfgang Goethe University, Institute of Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Max von Laue Strasse 7, 60438 Frankfurt/Main, Germany
| | - Dean-Paulos Klötzner
- Institute of Organic Chemistry and Chemical Biology, Max von Laue Strasse 7, 60438 Frankfurt/Main, Germany
| | - Alexander Heckel
- Institute of Organic Chemistry and Chemical Biology, Max von Laue Strasse 7, 60438 Frankfurt/Main, Germany
| | - Harald Schwalbe
- Johann Wolfgang Goethe University, Institute of Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Max von Laue Strasse 7, 60438 Frankfurt/Main, Germany
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18
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Hegelein A, Müller D, Größl S, Göbel M, Hengesbach M, Schwalbe H. Genetic Code Expansion Facilitates Position-Selective Labeling of RNA for Biophysical Studies. Chemistry 2020; 26:1800-1810. [PMID: 31692134 PMCID: PMC7027469 DOI: 10.1002/chem.201904623] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/04/2019] [Indexed: 12/13/2022]
Abstract
Nature relies on reading and synthesizing the genetic code with high fidelity. Nucleic acid building blocks that are orthogonal to the canonical A-T and G-C base-pairs are therefore uniquely suitable to facilitate position-specific labeling of nucleic acids. Here, we employ the orthogonal kappa-xanthosine-base-pair for in vitro transcription of labeled RNA. We devised an improved synthetic route to obtain the phosphoramidite of the deoxy-version of the kappa nucleoside in solid phase synthesis. From this DNA template, we demonstrate the reliable incorporation of xanthosine during in vitro transcription. Using NMR spectroscopy, we show that xanthosine introduces only minor structural changes in an RNA helix. We furthermore synthesized a clickable 7-deaza-xanthosine, which allows to site-specifically modify transcribed RNA molecules with fluorophores or other labels.
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Affiliation(s)
- Andreas Hegelein
- Institute for Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic ResonanceGoethe University FrankfurtMax-von-Laue-Strasse 760438Frankfurt am MainGermany
| | - Diana Müller
- Institute for Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic ResonanceGoethe University FrankfurtMax-von-Laue-Strasse 760438Frankfurt am MainGermany
| | - Sylvester Größl
- Institute for Organic Chemistry and Chemical BiologyGoethe University FrankfurtMax-von-Laue-Strasse 760438Frankfurt am MainGermany
| | - Michael Göbel
- Institute for Organic Chemistry and Chemical BiologyGoethe University FrankfurtMax-von-Laue-Strasse 760438Frankfurt am MainGermany
| | - Martin Hengesbach
- Institute for Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic ResonanceGoethe University FrankfurtMax-von-Laue-Strasse 760438Frankfurt am MainGermany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical BiologyCenter for Biomolecular Magnetic ResonanceGoethe University FrankfurtMax-von-Laue-Strasse 760438Frankfurt am MainGermany
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19
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A 300-fold enhancement of imino nucleic acid resonances by hyperpolarized water provides a new window for probing RNA refolding by 1D and 2D NMR. Proc Natl Acad Sci U S A 2020; 117:2449-2455. [PMID: 31949004 DOI: 10.1073/pnas.1916956117] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
NMR sensitivity-enhancement methods involving hyperpolarized water could be of importance for solution-state biophysical investigations. Hyperpolarized water (HyperW) can enhance the 1H NMR signals of exchangeable sites by orders of magnitude over their thermal counterparts, while providing insight into chemical exchange and solvent accessibility at a site-resolved level. As HyperW's enhancements are achieved by exploiting fast solvent exchanges associated with minimal interscan delays, possibilities for the rapid monitoring of chemical reactions and biomolecular (re)folding are opened. HyperW NMR can also accommodate heteronuclear transfers, facilitating the rapid acquisition of 2-dimensional (2D) 15N-1H NMR correlations, and thereby combining an enhanced spectral resolution with speed and sensitivity. This work demonstrates how these qualities can come together for the study of nucleic acids. HyperW injections were used to target the guanine-sensing riboswitch aptamer domain (GSRapt) of the xpt-pbuX operon in Bacillus subtilis Unlike what had been observed in proteins, where residues benefited of HyperW NMR only if/when sufficiently exposed to water, these enhancements applied to every imino resonance throughout the RNA. The >300-fold enhancements observed in the resulting 1H NMR spectra allowed us to monitor in real time the changes that GSRapt undergoes upon binding hypoxanthine, a high-affinity interaction leading to conformational refolding on a ∼1-s timescale at 36 °C. Structural responses could be identified for several nucleotides by 1-dimensional (1D) imino 1H NMR as well as by 2D HyperW NMR spectra acquired upon simultaneous injection of hyperpolarized water and hypoxanthine. The folding landscape revealed by this HyperW strategy for GSRapt, is briefly discussed.
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20
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Grün JT, Hennecker C, Klötzner DP, Harkness RW, Bessi I, Heckel A, Mittermaier AK, Schwalbe H. Conformational Dynamics of Strand Register Shifts in DNA G-Quadruplexes. J Am Chem Soc 2019; 142:264-273. [PMID: 31815451 DOI: 10.1021/jacs.9b10367] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The complex folding energy landscape of DNA G-quadruplexes leads to numerous conformations for this functionally important class of noncanonical DNA structures. A new layer of conformational heterogeneity comes from sequences with different numbers of G-nucleotides in each of the DNA G-strands that form the four-stranded G-quartet core. The mechanisms by which G-quadruplexes transition from one folded conformation to another are currently unknown. To address this question, we studied two different G-quadruplexes, selecting a single conformation by blocking hydrogen bonding with photolabile protection groups. Upon irradiation, the block can be released and the kinetics of re-equilibration to the native conformational equilibrium can be determined by time-resolved NMR. We compared the NMR-derived refolding kinetics with data derived from thermal hysteresis folding kinetic experiments and found excellent agreement. The outlined methodological approach allows separation of K+-induced G-quadruplex formation and subsequent refolding and provides key insight into rate-limiting steps of G-quadruplex conformational dynamics.
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Affiliation(s)
- J Tassilo Grün
- Institute for Organic Chemistry and Chemical Biology , Goethe University Frankfurt am Main , Frankfurt 60438 , Germany.,Center of Biomolecular Magnetic Resonance (BMRZ) , Goethe University Frankfurt am Main , Frankfurt 60438 , Germany
| | | | - Dean-Paulos Klötzner
- Institute for Organic Chemistry and Chemical Biology , Goethe University Frankfurt am Main , Frankfurt 60438 , Germany
| | - Robert W Harkness
- Department of Chemistry , McGill University , Montreal H3A 2K6 , Quebec , Canada
| | - Irene Bessi
- Institute of Organic Chemistry , Julius-Maximilians-University Würzburg , Würzburg 97074 , Germany
| | - Alexander Heckel
- Institute for Organic Chemistry and Chemical Biology , Goethe University Frankfurt am Main , Frankfurt 60438 , Germany
| | | | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology , Goethe University Frankfurt am Main , Frankfurt 60438 , Germany.,Center of Biomolecular Magnetic Resonance (BMRZ) , Goethe University Frankfurt am Main , Frankfurt 60438 , Germany
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21
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Marušič M, Schlagnitweit J, Petzold K. RNA Dynamics by NMR Spectroscopy. Chembiochem 2019; 20:2685-2710. [PMID: 30997719 PMCID: PMC6899578 DOI: 10.1002/cbic.201900072] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/12/2019] [Indexed: 12/22/2022]
Abstract
An ever-increasing number of functional RNAs require a mechanistic understanding. RNA function relies on changes in its structure, so-called dynamics. To reveal dynamic processes and higher energy structures, new NMR methods have been developed to elucidate these dynamics in RNA with atomic resolution. In this Review, we provide an introduction to dynamics novices and an overview of methods that access most dynamic timescales, from picoseconds to hours. Examples are provided as well as insight into theory, data acquisition and analysis for these different methods. Using this broad spectrum of methodology, unprecedented detail and invisible structures have been obtained and are reviewed here. RNA, though often more complicated and therefore neglected, also provides a great system to study structural changes, as these RNA structural changes are more easily defined-Lego like-than in proteins, hence the numerous revelations of RNA excited states.
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Affiliation(s)
- Maja Marušič
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetSolnavägen 917177StockholmSweden
| | - Judith Schlagnitweit
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetSolnavägen 917177StockholmSweden
| | - Katja Petzold
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetSolnavägen 917177StockholmSweden
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22
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Combined smFRET and NMR analysis of riboswitch structural dynamics. Methods 2019; 153:22-34. [DOI: 10.1016/j.ymeth.2018.10.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 12/13/2022] Open
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23
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Seyfried P, Heinz M, Pintér G, Klötzner DP, Becker Y, Bolte M, Jonker HRA, Stelzl LS, Hummer G, Schwalbe H, Heckel A. Optimal Destabilization of DNA Double Strands by Single-Nucleobase Caging. Chemistry 2018; 24:17568-17576. [DOI: 10.1002/chem.201804040] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Patrick Seyfried
- Institute for Organic Chemistry and Chemical Biology; Goethe University Frankfurt; Max-von-Laue-Str. 7 60438 Frankfurt am Main Germany
| | - Marcel Heinz
- Department of Theoretical Biophysics; Max Planck Institute of Biophysics; Max-von-Laue-Str. 3 60438 Frankfurt am Main Germany
| | - György Pintér
- Institute for Organic Chemistry and Chemical Biology; Goethe University Frankfurt/, Centre for Biomolecular Magnetic Resonance (BMRZ); Max-von-Laue-Str. 7 60438 Frankfurt am Main Germany
| | - Dean-Paulos Klötzner
- Institute for Organic Chemistry and Chemical Biology; Goethe University Frankfurt; Max-von-Laue-Str. 7 60438 Frankfurt am Main Germany
| | - Yvonne Becker
- Institute for Organic Chemistry and Chemical Biology; Goethe University Frankfurt; Max-von-Laue-Str. 7 60438 Frankfurt am Main Germany
| | - Michael Bolte
- Institute for Inorganic Chemistry; Goethe University Frankfurt; Max-von-Laue-Str. 7 60438 Frankfurt am Main Germany
| | - Hendrik R. A. Jonker
- Institute for Organic Chemistry and Chemical Biology; Goethe University Frankfurt/, Centre for Biomolecular Magnetic Resonance (BMRZ); Max-von-Laue-Str. 7 60438 Frankfurt am Main Germany
| | - Lukas S. Stelzl
- Department of Theoretical Biophysics; Max Planck Institute of Biophysics; Max-von-Laue-Str. 3 60438 Frankfurt am Main Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics; Max Planck Institute of Biophysics; Max-von-Laue-Str. 3 60438 Frankfurt am Main Germany
- Institute of Biophysics; Max-von-Laue-Str. 1 60438 Frankfurt am Main Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology; Goethe University Frankfurt/, Centre for Biomolecular Magnetic Resonance (BMRZ); Max-von-Laue-Str. 7 60438 Frankfurt am Main Germany
| | - Alexander Heckel
- Institute for Organic Chemistry and Chemical Biology; Goethe University Frankfurt; Max-von-Laue-Str. 7 60438 Frankfurt am Main Germany
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24
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Boswell ZK, Latham MP. Methyl-Based NMR Spectroscopy Methods for Uncovering Structural Dynamics in Large Proteins and Protein Complexes. Biochemistry 2018; 58:144-155. [PMID: 30336000 DOI: 10.1021/acs.biochem.8b00953] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
NMR spectroscopy is particularly adept at site-specifically monitoring dynamic processes in proteins, such as protein folding, domain movements, ligand binding, and side-chain rotations. By coupling the favorable spectroscopic properties of highly dynamic side-chain methyl groups with transverse-relaxation-optimized spectroscopy (TROSY), it is now possible to routinely study such dynamic processes in high-molecular-weight proteins and complexes approaching 1 MDa. In this Perspective, we describe many elegant methyl-based NMR experiments that probe slow (second) to fast (picosecond) dynamics in large systems. To demonstrate the power of these methods, we also provide interesting examples of studies that utilized each methyl-based NMR technique to uncover functionally important dynamics. In many cases, the NMR experiments are paired with site-directed mutagenesis and/or other biochemical assays to put the dynamics and function into context. Our vision of the future of structural biology involves pairing methyl-based NMR spectroscopy with biochemical studies to advance our knowledge of the motions large proteins and macromolecular complexes use to choreograph complex functions. Such studies will be essential in elucidating the critical structural dynamics that underlie function and characterizing alterations in these processes that can lead to human disease.
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Affiliation(s)
- Zachary K Boswell
- Department of Chemistry and Biochemistry , Texas Tech University , Lubbock , Texas 79423 , United States
| | - Michael P Latham
- Department of Chemistry and Biochemistry , Texas Tech University , Lubbock , Texas 79423 , United States
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25
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Vicens Q, Mondragón E, Reyes FE, Coish P, Aristoff P, Berman J, Kaur H, Kells KW, Wickens P, Wilson J, Gadwood RC, Schostarez HJ, Suto RK, Blount KF, Batey RT. Structure-Activity Relationship of Flavin Analogues That Target the Flavin Mononucleotide Riboswitch. ACS Chem Biol 2018; 13:2908-2919. [PMID: 30107111 DOI: 10.1021/acschembio.8b00533] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The flavin mononucleotide (FMN) riboswitch is an emerging target for the development of novel RNA-targeting antibiotics. We previously discovered an FMN derivative, 5FDQD, that protects mice against diarrhea-causing Clostridium difficile bacteria. Here, we present the structure-based drug design strategy that led to the discovery of this fluoro-phenyl derivative with antibacterial properties. This approach involved the following stages: (1) structural analysis of all available free and bound FMN riboswitch structures; (2) design, synthesis, and purification of derivatives; (3) in vitro testing for productive binding using two chemical probing methods; (4) in vitro transcription termination assays; and (5) resolution of the crystal structures of the FMN riboswitch in complex with the most mature candidates. In the process, we delineated principles for productive binding to this riboswitch, thereby demonstrating the effectiveness of a coordinated structure-guided approach to designing drugs against RNA.
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Affiliation(s)
- Quentin Vicens
- Department of Chemistry and Biochemistry, University of Colorado, 596 UCB, Boulder, Colorado 80309, United States
| | - Estefanía Mondragón
- Department of Chemistry and Biochemistry, University of Colorado, 596 UCB, Boulder, Colorado 80309, United States
| | - Francis E. Reyes
- Department of Chemistry and Biochemistry, University of Colorado, 596 UCB, Boulder, Colorado 80309, United States
| | - Philip Coish
- BioRelix Inc., 124 Washington Street, Foxborough, Massachusetts 02035, United States
| | - Paul Aristoff
- Aristoff Consulting LLC, 3726 Green Spring Drive, Fort Collins, Colorado 80528, United States
| | - Judd Berman
- Dalton Pharma Services, 349 Wildcat Road, Toronto, ON M3J 2S3, Canada
| | - Harpreet Kaur
- Dalton Pharma Services, 349 Wildcat Road, Toronto, ON M3J 2S3, Canada
| | - Kevin W. Kells
- Dalton Pharma Services, 349 Wildcat Road, Toronto, ON M3J 2S3, Canada
| | - Phil Wickens
- Dalton Pharma Services, 349 Wildcat Road, Toronto, ON M3J 2S3, Canada
| | - Jeffery Wilson
- Dalton Pharma Services, 349 Wildcat Road, Toronto, ON M3J 2S3, Canada
| | - Robert C. Gadwood
- Kalexsyn, Inc., 4502 Campus Drive, Kalamazoo, Michigan 49008, United States
| | | | - Robert K. Suto
- Xtal BioStructures, Inc., 12 Michigan Drive, Natick, Massachusetts 01760, United States
| | - Kenneth F. Blount
- BioRelix Inc., 124 Washington Street, Foxborough, Massachusetts 02035, United States
| | - Robert T. Batey
- Department of Chemistry and Biochemistry, University of Colorado, 596 UCB, Boulder, Colorado 80309, United States
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26
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Keyhani S, Goldau T, Blümler A, Heckel A, Schwalbe H. Chemo-Enzymatic Synthesis of Position-Specifically Modified RNA for Biophysical Studies including Light Control and NMR Spectroscopy. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201807125] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sara Keyhani
- Institute for Organic Chemistry and Chemical Biology; Center for Biomolecular Magnetic Resonance; Goethe University Frankfurt am Main; Max-von-Laue-Strasse 7 60438 Frankfurt/Main Germany
- Institute for Organic Chemistry and Chemical Biology; Goethe University Frankfurt am Main; Max-von-Laue-Strasse 7 60438 Frankfurt/Main Germany
| | - Thomas Goldau
- Institute for Organic Chemistry and Chemical Biology; Goethe University Frankfurt am Main; Max-von-Laue-Strasse 7 60438 Frankfurt/Main Germany
| | - Anja Blümler
- Institute for Organic Chemistry and Chemical Biology; Goethe University Frankfurt am Main; Max-von-Laue-Strasse 7 60438 Frankfurt/Main Germany
| | - Alexander Heckel
- Institute for Organic Chemistry and Chemical Biology; Goethe University Frankfurt am Main; Max-von-Laue-Strasse 7 60438 Frankfurt/Main Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology; Center for Biomolecular Magnetic Resonance; Goethe University Frankfurt am Main; Max-von-Laue-Strasse 7 60438 Frankfurt/Main Germany
- Institute for Organic Chemistry and Chemical Biology; Goethe University Frankfurt am Main; Max-von-Laue-Strasse 7 60438 Frankfurt/Main Germany
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27
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Keyhani S, Goldau T, Blümler A, Heckel A, Schwalbe H. Chemo-Enzymatic Synthesis of Position-Specifically Modified RNA for Biophysical Studies including Light Control and NMR Spectroscopy. Angew Chem Int Ed Engl 2018; 57:12017-12021. [PMID: 30007102 DOI: 10.1002/anie.201807125] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Indexed: 02/04/2023]
Abstract
The investigation of non-coding RNAs requires RNAs containing modifications at every possible position within the oligonucleotide. Here, we present the chemo-enzymatic RNA synthesis containing photoactivatable or 13 C,15 N-labelled nucleosides. All four ribonucleotides containing ortho-nitrophenylethyl (NPE) photocages, photoswitchable azobenzene C-nucleotides and 13 C,15 N-labelled nucleotides were incorporated position-specifically in high yields. We applied this approach for the synthesis of light-inducible 2'dG-sensing riboswitch variants and detected ligand-induced structural reorganization upon irradiation by NMR spectroscopy. This chemo-enzymatic method opens the possibility to incorporate a wide range of modifications at any desired position of RNAs of any lengths beyond the limits of solid-phase synthesis.
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Affiliation(s)
- Sara Keyhani
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany.,Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt am Main, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Thomas Goldau
- Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt am Main, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Anja Blümler
- Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt am Main, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Alexander Heckel
- Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt am Main, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany.,Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt am Main, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
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28
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Carr CE, Marky LA. Increased Flexibility between Stems of Intramolecular Three-Way Junctions by the Insertion of Bulges. Biophys J 2018; 114:2764-2774. [PMID: 29925014 PMCID: PMC6026347 DOI: 10.1016/j.bpj.2018.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/25/2018] [Accepted: 05/01/2018] [Indexed: 12/20/2022] Open
Abstract
Intramolecular junctions are a ubiquitous structure within DNA and RNA; three-way junctions in particular have high strain around the junction because of the lack of flexibility, preventing the junctions from adopting conformations that would allow for optimal folding. In this work, we used a combination of calorimetric and spectroscopic techniques to study the unfolding of four intramolecular three-way junctions. The control three-way junction, 3H, has the sequence d(GAAATTGCGCT5GCGCGTGCT5GCACAATTTC), which has three arms of different sequences. We studied three other three-way junctions in which one (2HS1H), two (HS12HS1), and three (HS1HS1HS1) cytosine bulges were placed at the junction to allow the arms to adopt a wider range of conformations that may potentially relieve strain. Through calorimetric studies, it was concluded that bulges produce only minor effects on the enthalpic and thermal stability at physiological salt concentrations for 2HS1H and HS1HS1HS1. HS12HS1 displays the strongest effect, with the GTGC stem lacking a defined transition. In addition to unfolding thermodynamics, the differential binding of counterions, water, and protons was determined. It was found that with each bulge, there was a large increase in the binding of counterions; this correlated with a decrease in the immobilization of structural water molecules. The increase in counterion uptake upon folding likely displaces binding of structural water, which is measured by the osmotic stress method, in favor of electrostricted waters. The cytosine bulges do not affect the binding of protons; this finding indicates that the bulges are not forming base-triplet stacks. These results indicate that bulges in junctions do not affect the unfolding profile or the enthalpy of oligonucleotides but do affect the number and amount of molecules immobilized by the junction.
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Affiliation(s)
- Carolyn E Carr
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska
| | - Luis A Marky
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska.
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29
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Kerzhner M, Matsuoka H, Wuebben C, Famulok M, Schiemann O. High-Yield Spin Labeling of Long RNAs for Electron Paramagnetic Resonance Spectroscopy. Biochemistry 2018; 57:2923-2931. [PMID: 29715006 DOI: 10.1021/acs.biochem.8b00040] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Site-directed spin labeling is a powerful tool for investigating the conformation and dynamics of biomacromolecules such as RNA. Here we introduce a spin labeling strategy based on click chemistry in solution that, in combination with enzymatic ligation, allows highly efficient labeling of complex and long RNAs with short reaction times and suppressed RNA degradation. With this approach, a 34-nucleotide aptamer domain of the preQ1 riboswitch and an 81-nucleotide TPP riboswitch aptamer could be labeled with two labels in several positions. We then show that conformations of the preQ1 aptamer and its dynamics can be monitored in the absence and presence of Mg2+ and a preQ1 ligand by continuous wave electron paramagnetic resonance spectroscopy at room temperature and pulsed electron-electron double resonance spectroscopy (PELDOR or DEER) in the frozen state.
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Affiliation(s)
- Mark Kerzhner
- Life & Medical Sciences Institute Chemical Biology & Medicinal Chemistry Unit c/o Kekulé-Institut für Organische Chemie und Biochemie University of Bonn , Gerhard-Domagk-Strasse 1 , 53121 Bonn , Germany
| | - Hideto Matsuoka
- Institute of Physical and Theoretical Chemistry , University of Bonn , Wegelerstrasse 12 , 53115 Bonn , Germany
| | - Christine Wuebben
- Institute of Physical and Theoretical Chemistry , University of Bonn , Wegelerstrasse 12 , 53115 Bonn , Germany
| | - Michael Famulok
- Life & Medical Sciences Institute Chemical Biology & Medicinal Chemistry Unit c/o Kekulé-Institut für Organische Chemie und Biochemie University of Bonn , Gerhard-Domagk-Strasse 1 , 53121 Bonn , Germany.,Max Planck Fellowship Chemical Biology Group , Stiftung caesar , Ludwig-Erhard-Allee 2 , 53175 Bonn , Germany
| | - Olav Schiemann
- Institute of Physical and Theoretical Chemistry , University of Bonn , Wegelerstrasse 12 , 53115 Bonn , Germany
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30
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Carr CE, Marky LA. Effect of GCAA stabilizing loops on three- and four-way intramolecular junctions. Phys Chem Chem Phys 2018; 20:5046-5056. [PMID: 29388988 DOI: 10.1039/c7cp08329g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Tetraloops are a common way of changing the melting behavior of a DNA or RNA structure without changing the sequence of the stem. Because of the ubiquitous nature of tetraloops, our goal is to understand the effect a GCAA tetraloop, which belongs to the GNRA family of tetraloops, has on the unfolding thermodynamics of intramolecular junctions. Specifically, we have described the melting behavior of intramolecular three-way and four-way junctions where a T5 loop has been replaced with a GCAA tetraloops in different positions. Their thermodynamic profiles, including ΔnNa+ and ΔnW, were analyzed based on the position of the tetraloop. We obtained between -16.7 and -27.5 kcal mol-1 for all junctions studied. The experimental data indicates the influence of the GCAA tetraloop is primarily dictated by the native unfolding of the junction; if the tetraloop is placed on a stem that unfolds as a single domain when the tetraloop is not present, it will unfold as a single domain when the tetraloop is present but with a higher thermal stability. Conversely, if the tetraloop is placed on a stem which unfolds cooperatively with other stems when the tetraloop is not present, the tetraloop will increase the thermal stability of all the stems in the melting domain. The oligonucleotide structure and not the tetraloop itself affects ion uptake; three-way junctions do not gain an increase in ion uptake, but four-way junctions do. This is not the case for water immobilization, where the position of the tetraloop dictates the amount of water immobilized.
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Affiliation(s)
- Carolyn E Carr
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE 68198-6025, USA.
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31
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Williams B, Zhao B, Tandon A, Ding F, Weeks KM, Zhang Q, Dokholyan NV. Structure modeling of RNA using sparse NMR constraints. Nucleic Acids Res 2018; 45:12638-12647. [PMID: 29165648 PMCID: PMC5728392 DOI: 10.1093/nar/gkx1058] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 10/18/2017] [Indexed: 01/04/2023] Open
Abstract
RNAs fold into distinct molecular conformations that are often essential for their functions. Accurate structure modeling of complex RNA motifs, including ubiquitous non-canonical base pairs and pseudoknots, remains a challenge. Here, we present an NMR-guided all-atom discrete molecular dynamics (DMD) platform, iFoldNMR, for rapid and accurate structure modeling of complex RNAs. We show that sparse distance constraints from imino resonances, which can be readily obtained from routine NMR experiments and easier to compile than laborious assignments of non-solvent-exchangeable protons, are sufficient to direct a DMD search for low-energy RNA conformers. Benchmarking on a set of RNAs with complex folds spanning up to 56 nucleotides in length yields structural models that recapitulate experimentally determined structures with all-heavy-atom RMSDs ranging from 2.4 to 6.5 Å. This platform represents an efficient approach for high-throughput RNA structure modeling and will facilitate analysis of diverse, newly discovered functional RNAs.
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Affiliation(s)
- Benfeard Williams
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Molecular and Cellular Biophysics Program, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Bo Zhao
- Molecular and Cellular Biophysics Program, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Arpit Tandon
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Molecular and Cellular Biophysics Program, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Kevin M Weeks
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Qi Zhang
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Molecular and Cellular Biophysics Program, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nikolay V Dokholyan
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Molecular and Cellular Biophysics Program, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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32
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Carr CE, Marky LA. Investigation of the Melting Behavior of DNA Three-Way Junctions in the Closed and Open States. Biophys J 2017; 113:529-539. [PMID: 28793208 DOI: 10.1016/j.bpj.2017.06.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 06/09/2017] [Accepted: 06/14/2017] [Indexed: 10/19/2022] Open
Abstract
Intramolecular three-way junctions are commonly found in both DNA and RNA. These structures are functionally relevant in ribozymes, riboswitches, rRNA, and during replication. In this work, we present a thermodynamic description of the unfolding of DNA intramolecular three-way junctions. We used a combination of spectroscopic and calorimetric techniques to investigate the folding/unfolding thermodynamics of two three-way junctions with a closed (Closed-J) or open (Open-J) junction and their appropriate control stem-loop motifs (GAAATT-Hp, CTATC-Hp, and Dumbbell). The overall results show that both junctions are stable over a wide range of salt concentrations. However, Open-J is more stable due to a higher enthalpy contribution from the formation of a higher number of basepair stacks whereas Closed-J has a defined structure and retains the basepair stacking of all three stems. The comparison of the experimental results of Closed-J and Open-J with those of their component stem-loop motifs allowed us to be more specific about their cooperative unfolding. For instance, Closed-J sacrifices thermal stability of the Dumbbell structure to maintain an overall folded state. At higher salt concentration, the simultaneous unfolding of the above domains is lost, resulting in the unfolding of the three separate stems. In contrast, the junction of Open-J in low salt retains the thermal and enthalpic stability of the Dumbbell structure although sacrificing stability of the CTATC stem. The relative stability of Dumbbell is the primary reason for the higher ΔG°(5), or free energy, value seen for Open-J at low salt. Higher salt not only maintains thermal stability of the Dumbbell structure in Open-J but causes the CTATC stem to fully fold.
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Affiliation(s)
- Carolyn E Carr
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Nebraska Medical Center, Omaha, Nebraska
| | - Luis A Marky
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Nebraska Medical Center, Omaha, Nebraska.
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33
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Hanke CA, Gohlke H. Ligand-mediated and tertiary interactions cooperatively stabilize the P1 region in the guanine-sensing riboswitch. PLoS One 2017; 12:e0179271. [PMID: 28640851 PMCID: PMC5480868 DOI: 10.1371/journal.pone.0179271] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 05/27/2017] [Indexed: 12/18/2022] Open
Abstract
Riboswitches are genetic regulatory elements that control gene expression depending on ligand binding. The guanine-sensing riboswitch (Gsw) binds ligands at a three-way junction formed by paired regions P1, P2, and P3. Loops L2 and L3 cap the P2 and P3 helices and form tertiary interactions. Part of P1 belongs to the switching sequence dictating the fate of the mRNA. Previous studies revealed an intricate relationship between ligand binding and presence of the tertiary interactions, and between ligand binding and influence on the P1 region. However, no information is available on the interplay among these three main regions in Gsw. Here we show that stabilization of the L2-L3 region by tertiary interactions, and the ligand binding site by ligand binding, cooperatively influences the structural stability of terminal base pairs in the P1 region in the presence of Mg2+ ions. The results are based on molecular dynamics simulations with an aggregate simulation time of ~10 μs across multiple systems of the unbound state of the Gsw aptamer and a G37A/C61U mutant, and rigidity analyses. The results could explain why the three-way junction is a central structural element also in other riboswitches and how the cooperative effect could become contextual with respect to intracellular Mg2+ concentration. The results suggest that the transmission of allosteric information to P1 can be entropy-dominated.
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Affiliation(s)
- Christian A. Hanke
- Mathematisch-Naturwissenschaftliche Fakultät, Institut für Pharmazeutische und Medizinische Chemie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Holger Gohlke
- Mathematisch-Naturwissenschaftliche Fakultät, Institut für Pharmazeutische und Medizinische Chemie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
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34
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Schnorr KA, Gophane DB, Helmling C, Cetiner E, Pasemann K, Fürtig B, Wacker A, Qureshi NS, Gränz M, Barthelmes D, Jonker HRA, Stirnal E, Sigurdsson ST, Schwalbe H. Impact of spin label rigidity on extent and accuracy of distance information from PRE data. JOURNAL OF BIOMOLECULAR NMR 2017; 68:53-63. [PMID: 28500543 DOI: 10.1007/s10858-017-0114-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 05/03/2017] [Indexed: 06/07/2023]
Abstract
Paramagnetic relaxation enhancement (PRE) is a versatile tool for NMR spectroscopic structural and kinetic studies in biological macromolecules. Here, we compare the quality of PRE data derived from two spin labels with markedly different dynamic properties for large RNAs using the I-A riboswitch aptamer domain (78 nt) from Mesoplamsa florum as model system. We designed two I-A aptamer constructs that were spin-labeled by noncovalent hybridization of short spin-labeled oligomer fragments. As an example of a flexible spin label, UreidoU-TEMPO was incorporated into the 3' terminal end of helix P1 while, the recently developed rigid spin-label Çm was incorporated in the 5' terminal end of helix P1. We determined PRE rates obtained from aromatic 13C bound proton intensities and compared these rates to PREs derived from imino proton intensities in this sizeable RNA (~78 nt). PRE restraints derived from both imino and aromatic protons yielded similar data quality, and hence can both be reliably used for PRE determination. For NMR, the data quality derived from the rigid spin label Çm is slightly better than the data quality for the flexible UreidoTEMPO as judged by comparison of the structural agreement with the I-A aptamer crystal structure (3SKI).
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Affiliation(s)
- K A Schnorr
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-Universität, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - D B Gophane
- Department of Chemistry, Science Institute, University of Iceland, Dunhaga 3, 107, Reykjavik, Iceland
| | - C Helmling
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-Universität, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - E Cetiner
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-Universität, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - K Pasemann
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-Universität, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - B Fürtig
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-Universität, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - A Wacker
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-Universität, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - N S Qureshi
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-Universität, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - M Gränz
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Physical and Theoretical Chemistry, Johann Wolfgang Goethe-Universität, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - D Barthelmes
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-Universität, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - H R A Jonker
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-Universität, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - E Stirnal
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-Universität, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - S Th Sigurdsson
- Department of Chemistry, Science Institute, University of Iceland, Dunhaga 3, 107, Reykjavik, Iceland
| | - H Schwalbe
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-Universität, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany.
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35
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Hu G, Ma A, Wang J. Ligand Selectivity Mechanism and Conformational Changes in Guanine Riboswitch by Molecular Dynamics Simulations and Free Energy Calculations. J Chem Inf Model 2017; 57:918-928. [PMID: 28345904 DOI: 10.1021/acs.jcim.7b00139] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Riboswitches regulate gene expression through direct and specific interactions with small metabolite molecules. Binding of a ligand to its RNA target is high selectivity and affinity and induces conformational changes of the RNA's secondary and tertiary structure. The structural difference of two purine riboswitches aptamers is caused by only one single mutation, where cytosine 74 in the guanine riboswitch is corresponding to a uracil 74 in adenine riboswitch. Here we employed molecular dynamics (MD) simulation, molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) and thermodynamic integration computational methodologies to evaluate the energetic and conformational changes of ligands binding to purine riboswitches. The snapshots used in MM-PBSA calculation were extracted from ten 50 ns MD simulation trajectories for each complex. These free energy results are in consistent with the experimental data and rationalize the selectivity of the riboswitches for different ligands. In particular, it is found that the loss in binding free energy upon mutation is mainly electrostatic in guanine (GUA) and riboswitch complex. Furthermore, new hydrogen bonds are found in mutated complexes. To reveal the conformational properties of guanine riboswitch, we performed a total of 6 μs MD simulations in both the presence and the absence of the ligand GUA. The MD simulations suggest that the conformation of guanine riboswitch depends on the distance of two groups in the binding pocket of ligand. The conformation is in a close conformation when U51-A52 is close to C74-U75.
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Affiliation(s)
- Guodong Hu
- Shandong Provincial Key Laboratory of Biophysics, College of Physics and Electronic Information, Dezhou University , Dezhou 253023, China
| | - Aijing Ma
- Shandong Provincial Key Laboratory of Biophysics, College of Physics and Electronic Information, Dezhou University , Dezhou 253023, China
| | - Jihua Wang
- Shandong Provincial Key Laboratory of Biophysics, College of Physics and Electronic Information, Dezhou University , Dezhou 253023, China
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36
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Jones CP, Ferré-D'Amaré AR. Long-Range Interactions in Riboswitch Control of Gene Expression. Annu Rev Biophys 2017; 46:455-481. [PMID: 28375729 DOI: 10.1146/annurev-biophys-070816-034042] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Riboswitches are widespread RNA motifs that regulate gene expression in response to fluctuating metabolite concentrations. Known primarily from bacteria, riboswitches couple specific ligand binding and changes in RNA structure to mRNA expression in cis. Crystal structures of the ligand binding domains of most of the phylogenetically widespread classes of riboswitches, each specific to a particular metabolite or ion, are now available. Thus, the bound states-one end point-have been thoroughly characterized, but the unbound states have been more elusive. Consequently, it is less clear how the unbound, sensing riboswitch refolds into the ligand binding-induced output state. The ligand recognition mechanisms of riboswitches are diverse, but we find that they share a common structural strategy in positioning their binding sites at the point of the RNA three-dimensional fold where the residues farthest from one another in sequence meet. We review how riboswitch folds adhere to this fundamental strategy and propose future research directions for understanding and harnessing their ability to specifically control gene expression.
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Affiliation(s)
- Christopher P Jones
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20824;
| | - Adrian R Ferré-D'Amaré
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20824;
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37
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Chandra V, Hannan Z, Xu H, Mandal M. Single-molecule analysis reveals multi-state folding of a guanine riboswitch. Nat Chem Biol 2016; 13:194-201. [PMID: 27941758 DOI: 10.1038/nchembio.2252] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 10/03/2016] [Indexed: 12/29/2022]
Abstract
Guanine-responsive riboswitches undergo ligand-dependent structural rearrangements to control gene expression by transcription termination. While the molecular basis for ligand recognition is well established, the associated structural rearrangements and the kinetics involved in the formation of the aptamer domain are less well understood. Using high-resolution optical tweezers, we followed the folding trajectories of a single molecule of the xpt-pbuX guanine aptamer from Bacillus subtilis. We report a rapid six-state conformational rearrangement, in which three of the states are guanine dependent, during the transition from the linear to the native receptor conformation. The folding completes in <1 s. The force-dependent equilibrium kinetics and the mutational data indicated that the flexible J2-J3 junction undergoes a ligand-dependent conformational switching, which triggers the formation of the long-range tertiary interactions and the P1 helix. In the absence of the right ligand, the junction failed to initiate the series of conformational rearrangements required for the riboswitch activities.
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Affiliation(s)
- Vishnu Chandra
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Zain Hannan
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Huizhong Xu
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Maumita Mandal
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA.,Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA.,Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
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38
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Challier L, Miranda-Castro R, Barbe B, Fave C, Limoges B, Peyrin E, Ravelet C, Fiore E, Labbé P, Coche-Guérente L, Ennifar E, Bec G, Dumas P, Mavré F, Noël V. Multianalytical Study of the Binding between a Small Chiral Molecule and a DNA Aptamer: Evidence for Asymmetric Steric Effect upon 3'- versus 5'-End Sequence Modification. Anal Chem 2016; 88:11963-11971. [PMID: 27934108 DOI: 10.1021/acs.analchem.6b04046] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Nucleic acid aptamers are involved in a broad field of applications ranging from therapeutics to analytics. Deciphering the binding mechanisms between aptamers and small ligands is therefore crucial to improve and optimize existing applications and to develop new ones. Particularly interesting is the enantiospecific binding mechanism involving small molecules with nonprestructured aptamers. One archetypal example is the chiral binding between l-tyrosinamide and its 49-mer aptamer for which neither structural nor mechanistic information is available. In the present work, we have taken advantage of a multiple analytical characterization strategy (i.e., using electroanalytical techniques such as kinetic rotating droplet electrochemistry, fluorescence polarization, isothermal titration calorimetry, and quartz crystal microbalance) for interpreting the nature of binding process. Screening of the binding thermodynamics and kinetics with a wide range of aptamer sequences revealed the lack of symmetry between the two ends of the 23-mer minimal binding sequence, showing an unprecedented influence of the 5' aptamer modification on the bimolecular binding rate constant kon and no significant effect on the dissociation rate constant koff. The results we have obtained lead us to conclude that the enantiospecific binding reaction occurs through an induced-fit mechanism, wherein the ligand promotes a primary nucleation binding step near the 5'-end of the aptamer followed by a directional folding of the aptamer around its target from 5'-end to 3'-end. Functionalization of the 5'-end position by a chemical label, a polydA tail, a protein, or a surface influences the kinetic/thermodynamic constants up to 2 orders of magnitude in the extreme case of a surface immobilized aptamer, while significantly weaker effect is observed for a 3'-end modification. The reason is that steric hindrance must be overcome to nucleate the binding complex in the presence of a modification near the nucleation site.
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Affiliation(s)
- Lylian Challier
- ITODYS, UMR 7086 CNRS, Université Paris Diderot, Sorbonne Paris Cité , 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Rebeca Miranda-Castro
- ITODYS, UMR 7086 CNRS, Université Paris Diderot, Sorbonne Paris Cité , 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Bertrand Barbe
- ITODYS, UMR 7086 CNRS, Université Paris Diderot, Sorbonne Paris Cité , 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Claire Fave
- Laboratoire d'Electrochimie Moléculaire, UMR 7591 CNRS, Université Paris Diderot, Sorbonne Paris Cité , 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Benoît Limoges
- Laboratoire d'Electrochimie Moléculaire, UMR 7591 CNRS, Université Paris Diderot, Sorbonne Paris Cité , 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Eric Peyrin
- Département de Pharmacochimie Moléculaire, UMR 5063 CNRS, Université Grenoble Alpes , 470 rue de la chimie, 38400 Saint-Martin d'Hères, France
| | - Corinne Ravelet
- Département de Pharmacochimie Moléculaire, UMR 5063 CNRS, Université Grenoble Alpes , 470 rue de la chimie, 38400 Saint-Martin d'Hères, France
| | - Emmanuelle Fiore
- Département de Pharmacochimie Moléculaire, UMR 5063 CNRS, Université Grenoble Alpes , 470 rue de la chimie, 38400 Saint-Martin d'Hères, France
| | - Pierre Labbé
- Département de Chimie Moléculaire, CNRS, UMR 5250, Université Grenoble Alpes , FR 2607, 570 rue de la chimie, B.P. 53, 38400 Grenoble, France
| | - Liliane Coche-Guérente
- Département de Chimie Moléculaire, CNRS, UMR 5250, Université Grenoble Alpes , FR 2607, 570 rue de la chimie, B.P. 53, 38400 Grenoble, France
| | - Eric Ennifar
- "Architecture et Réactivité de l'ARN", Biophysique et Biologie Structurale, Institut de Biologie Moléculaire et Cellulaire du CNRS, Université de Strasbourg , 15 rue René Descartes, 67084 Strasbourg, France
| | - Guillaume Bec
- "Architecture et Réactivité de l'ARN", Biophysique et Biologie Structurale, Institut de Biologie Moléculaire et Cellulaire du CNRS, Université de Strasbourg , 15 rue René Descartes, 67084 Strasbourg, France
| | - Philippe Dumas
- "Architecture et Réactivité de l'ARN", Biophysique et Biologie Structurale, Institut de Biologie Moléculaire et Cellulaire du CNRS, Université de Strasbourg , 15 rue René Descartes, 67084 Strasbourg, France
| | - François Mavré
- Laboratoire d'Electrochimie Moléculaire, UMR 7591 CNRS, Université Paris Diderot, Sorbonne Paris Cité , 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Vincent Noël
- ITODYS, UMR 7086 CNRS, Université Paris Diderot, Sorbonne Paris Cité , 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
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39
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D'Ascenzo L, Leonarski F, Vicens Q, Auffinger P. 'Z-DNA like' fragments in RNA: a recurring structural motif with implications for folding, RNA/protein recognition and immune response. Nucleic Acids Res 2016; 44:5944-56. [PMID: 27151194 PMCID: PMC4937326 DOI: 10.1093/nar/gkw388] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 04/28/2016] [Indexed: 01/09/2023] Open
Abstract
Since the work of Alexander Rich, who solved the first Z-DNA crystal structure, we have known that d(CpG) steps can adopt a particular structure that leads to forming left-handed helices. However, it is still largely unrecognized that other sequences can adopt ‘left-handed’ conformations in DNA and RNA, in double as well as single stranded contexts. These ‘Z-like’ steps involve the coexistence of several rare structural features: a C2’-endo puckering, a syn nucleotide and a lone pair–π stacking between a ribose O4’ atom and a nucleobase. This particular arrangement induces a conformational stress in the RNA backbone, which limits the occurrence of Z-like steps to ≈0.1% of all dinucleotide steps in the PDB. Here, we report over 600 instances of Z-like steps, which are located within r(UNCG) tetraloops but also in small and large RNAs including riboswitches, ribozymes and ribosomes. Given their complexity, Z-like steps are probably associated with slow folding kinetics and once formed could lock a fold through the formation of unique long-range contacts. Proteins involved in immunologic response also specifically recognize/induce these peculiar folds. Thus, characterizing the conformational features of these motifs could be a key to understanding the immune response at a structural level.
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Affiliation(s)
- Luigi D'Ascenzo
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg 67084, France
| | - Filip Leonarski
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg 67084, France Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Quentin Vicens
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg 67084, France
| | - Pascal Auffinger
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg 67084, France
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40
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Frener M, Micura R. Conformational Rearrangements of Individual Nucleotides during RNA-Ligand Binding Are Rate-Differentiated. J Am Chem Soc 2016; 138:3627-30. [PMID: 26974261 PMCID: PMC4959565 DOI: 10.1021/jacs.5b11876] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A pronounced rate differentiation has been found for conformational rearrangements of individual nucleobases that occur during ligand recognition of the preQ1 class-I riboswitch aptamer from Thermoanaerobacter tengcongensis. Rate measurements rely on the 2ApFold approach by analyzing the fluorescence response of riboswitch variants, each with a single, strategically positioned 2-aminopurine nucleobase substitution. Observed rate discrimination between the fastest and the slowest conformational adaption is 22-fold, with the largest rate observed for the rearrangement of a nucleoside directly at the binding site and the smallest rate observed for the 3'-unpaired nucleoside that stacks onto the pseudo-knot-closing Watson-Crick base pair. Our findings provide novel insights into how compact, prefolded RNAs that follow the induced-fit recognition mechanism adapt local structural elements in response to ligand binding on a rather broad time scale and how this process culminates in a structural signal that is responsible for efficient downregulation of ribosomal translation.
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Affiliation(s)
- Marina Frener
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
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41
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Abstract
Nuclear magnetic resonance (NMR) spectroscopy provides a unique toolbox of experimental probes for studying dynamic processes on a wide range of timescales, ranging from picoseconds to milliseconds and beyond. Along with NMR hardware developments, recent methodological advancements have enabled the characterization of allosteric proteins at unprecedented detail, revealing intriguing aspects of allosteric mechanisms and increasing the proportion of the conformational ensemble that can be observed by experiment. Here, we present an overview of NMR spectroscopic methods for characterizing equilibrium fluctuations in free and bound states of allosteric proteins that have been most influential in the field. By combining NMR experimental approaches with molecular simulations, atomistic-level descriptions of the mechanisms by which allosteric phenomena take place are now within reach.
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Affiliation(s)
- Sarina Grutsch
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Sven Brüschweiler
- Department of Computational & Structural Biology, Max F. Perutz Laboratories, Campus Vienna Biocenter 5, Vienna, Austria
| | - Martin Tollinger
- Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
- * E-mail:
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42
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Fürtig B, Schnieders R, Richter C, Zetzsche H, Keyhani S, Helmling C, Kovacs H, Schwalbe H. Direct ¹³C-detected NMR experiments for mapping and characterization of hydrogen bonds in RNA. JOURNAL OF BIOMOLECULAR NMR 2016; 64:207-221. [PMID: 26852414 DOI: 10.1007/s10858-016-0021-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 01/29/2016] [Indexed: 06/05/2023]
Abstract
In RNA secondary structure determination, it is essential to determine whether a nucleotide is base-paired and not. Base-pairing of nucleotides is mediated by hydrogen bonds. The NMR characterization of hydrogen bonds relies on experiments correlating the NMR resonances of exchangeable protons and can be best performed for structured parts of the RNA, where labile hydrogen atoms are protected from solvent exchange. Functionally important regions in RNA, however, frequently reveal increased dynamic disorder which often leads to NMR signals of exchangeable protons that are broadened beyond (1)H detection. Here, we develop (13)C direct detected experiments to observe all nucleotides in RNA irrespective of whether they are involved in hydrogen bonds or not. Exploiting the self-decoupling of scalar couplings due to the exchange process, the hydrogen bonding behavior of the hydrogen bond donor of each individual nucleotide can be determined. Furthermore, the adaption of HNN-COSY experiments for (13)C direct detection allows correlations of donor-acceptor pairs and the localization of hydrogen-bond acceptor nucleotides. The proposed (13)C direct detected experiments therefore provide information about molecular sites not amenable by conventional proton-detected methods. Such information makes the RNA secondary structure determination by NMR more accurate and helps to validate secondary structure predictions based on bioinformatics.
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Affiliation(s)
- Boris Fürtig
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe Universität Frankfurt, Max von Laue-Str. 7, 60438, Frankfurt, Germany.
| | - Robbin Schnieders
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe Universität Frankfurt, Max von Laue-Str. 7, 60438, Frankfurt, Germany
| | - Christian Richter
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe Universität Frankfurt, Max von Laue-Str. 7, 60438, Frankfurt, Germany
| | - Heidi Zetzsche
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe Universität Frankfurt, Max von Laue-Str. 7, 60438, Frankfurt, Germany
| | - Sara Keyhani
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe Universität Frankfurt, Max von Laue-Str. 7, 60438, Frankfurt, Germany
| | - Christina Helmling
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe Universität Frankfurt, Max von Laue-Str. 7, 60438, Frankfurt, Germany
| | - Helena Kovacs
- Bruker BioSpin, Industriestrasse 26, 8117, Fällanden, Switzerland
| | - Harald Schwalbe
- Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe Universität Frankfurt, Max von Laue-Str. 7, 60438, Frankfurt, Germany.
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43
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Sochor F, Silvers R, Müller D, Richter C, Fürtig B, Schwalbe H. (19)F-labeling of the adenine H2-site to study large RNAs by NMR spectroscopy. JOURNAL OF BIOMOLECULAR NMR 2016; 64:63-74. [PMID: 26704707 DOI: 10.1007/s10858-015-0006-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 12/20/2015] [Indexed: 05/24/2023]
Abstract
In comparison to proteins and protein complexes, the size of RNA amenable to NMR studies is limited despite the development of new isotopic labeling strategies including deuteration and ligation of differentially labeled RNAs. Due to the restricted chemical shift dispersion in only four different nucleotides spectral resolution remains limited in larger RNAs. Labeling RNAs with the NMR-active nucleus (19)F has previously been introduced for small RNAs up to 40 nucleotides (nt). In the presented work, we study the natural occurring RNA aptamer domain of the guanine-sensing riboswitch comprising 73 nucleotides from Bacillus subtilis. The work includes protocols for improved in vitro transcription of 2-fluoroadenosine-5'-triphosphat (2F-ATP) using the mutant P266L of the T7 RNA polymerase. Our NMR analysis shows that the secondary and tertiary structure of the riboswitch is fully maintained and that the specific binding of the cognate ligand hypoxanthine is not impaired by the introduction of the (19)F isotope. The thermal stability of the (19)F-labeled riboswitch is not altered compared to the unmodified sequence, but local base pair stabilities, as measured by hydrogen exchange experiments, are modulated. The characteristic change in the chemical shift of the imino resonances detected in a (1)H,(15)N-HSQC allow the identification of Watson-Crick base paired uridine signals and the (19)F resonances can be used as reporters for tertiary and secondary structure transitions, confirming the potential of (19)F-labeling even for sizeable RNAs in the range of 70 nucleotides.
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Affiliation(s)
- F Sochor
- Institut für Organische Chemie und Chemische Biologie, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt/M., Germany
| | - R Silvers
- Institut für Organische Chemie und Chemische Biologie, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt/M., Germany
- Department of Chemistry, Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - D Müller
- Institut für Organische Chemie und Chemische Biologie, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt/M., Germany
| | - C Richter
- Institut für Organische Chemie und Chemische Biologie, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt/M., Germany
| | - B Fürtig
- Institut für Organische Chemie und Chemische Biologie, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt/M., Germany.
| | - H Schwalbe
- Institut für Organische Chemie und Chemische Biologie, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt/M., Germany.
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44
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Ren A, Xue Y, Peselis A, Serganov A, Al-Hashimi HM, Patel DJ. Structural and Dynamic Basis for Low-Affinity, High-Selectivity Binding of L-Glutamine by the Glutamine Riboswitch. Cell Rep 2015; 13:1800-13. [PMID: 26655897 DOI: 10.1016/j.celrep.2015.10.062] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 08/17/2015] [Accepted: 10/20/2015] [Indexed: 12/24/2022] Open
Abstract
Naturally occurring L-glutamine riboswitches occur in cyanobacteria and marine metagenomes, where they reside upstream of genes involved in nitrogen metabolism. By combining X-ray, NMR, and MD, we characterized an L-glutamine-dependent conformational transition in the Synechococcus elongatus glutamine riboswitch from tuning fork to L-shaped alignment of stem segments. This transition generates an open ligand-binding pocket with L-glutamine selectivity enforced by Mg(2+)-mediated intermolecular interactions. The transition also stabilizes the P1 helix through a long-range "linchpin" Watson-Crick G-C pair-capping interaction, while melting a short helix below P1 potentially capable of modulating downstream readout. NMR data establish that the ligand-free glutamine riboswitch in Mg(2+) solution exists in a slow equilibrium between flexible tuning fork and a minor conformation, similar, but not identical, to the L-shaped bound conformation. We propose that an open ligand-binding pocket combined with a high conformational penalty for forming the ligand-bound state provide mechanisms for reducing binding affinity while retaining high selectivity.
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Affiliation(s)
- Aiming Ren
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Yi Xue
- Department of Biochemistry and Chemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Alla Peselis
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Alexander Serganov
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Hashim M Al-Hashimi
- Department of Biochemistry and Chemistry, Duke University Medical Center, Durham, NC 27710, USA.
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
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45
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Mills A, O’Rourke C. In Situ, Simultaneous Irradiation and Monitoring of a Photocatalyzed Organic Oxidation Reaction in a TiO2-Coated NMR Tube. J Org Chem 2015; 80:10342-5. [DOI: 10.1021/acs.joc.5b01001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrew Mills
- School of Chemistry and Chemical
Engineering, Queen’s University Belfast, Stranmillis Road, Belfast, BT9 5AG, United Kingdom
| | - Christopher O’Rourke
- School of Chemistry and Chemical
Engineering, Queen’s University Belfast, Stranmillis Road, Belfast, BT9 5AG, United Kingdom
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46
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Lannes L, Halder S, Krishnan Y, Schwalbe H. Tuning the pH Response of i-Motif DNA Oligonucleotides. Chembiochem 2015; 16:1647-56. [PMID: 26032298 DOI: 10.1002/cbic.201500182] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Indexed: 12/19/2022]
Abstract
Cytosine-rich single-stranded DNA oligonucleotides are able to adopt an i-motif conformation, a four-stranded structure, near a pH of 6. This unique pH-dependent conformational switch is reversible and hence can be controlled by changing the pH. Here, we show that the pH response range of the human telomeric i-motif can be shifted towards more basic pH values by introducing 5-methylcytidines (5-MeC) and towards more acidic pH values by introducing 5-bromocytidines (5-BrC). No thermal destabilisation was observed in these chemically modified i-motif sequences. The time required to attain the new conformation in response to sudden pH changes was slow for all investigated sequences but was found to be ten times faster in the 5-BrC derivative of the i-motif.
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Affiliation(s)
- Laurie Lannes
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt/Main (Germany)
| | - Saheli Halder
- National Centre for Biological Sciences, TIFR, GKVK Campus, Bellary Road, Bangalore 560065 (India)
| | - Yamuna Krishnan
- National Centre for Biological Sciences, TIFR, GKVK Campus, Bellary Road, Bangalore 560065 (India).,Department of Chemistry, University of Chicago, E305, GCIS, 929 E, 57th Street, Chicago, IL 60637 (USA)
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt/Main (Germany).
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47
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Fürtig B, Nozinovic S, Reining A, Schwalbe H. Multiple conformational states of riboswitches fine-tune gene regulation. Curr Opin Struct Biol 2015; 30:112-124. [PMID: 25727496 DOI: 10.1016/j.sbi.2015.02.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 02/06/2015] [Accepted: 02/11/2015] [Indexed: 01/08/2023]
Abstract
Riboswitches are structured regions of mRNAs that modulate gene expression in response to specific binding of low molecular-weight ligands. They function by induced transitions between different functional conformations. The standard model assumed that the two functional states, the ligand-bound and ligand-free state, populated only two stable conformations. Recent discoveries of multiple conformations for the apo-state and holo-state of riboswitches challenge this model. Moreover, it becomes evident that detected conformational heterogeneity--mostly in the apo-state--provides sensitivity to multiple environmental inputs for riboswitch-based gene-regulation.
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Affiliation(s)
- Boris Fürtig
- Institute of Organic Chemistry and Chemical Biology, BMRZ, Johann Wolfgang Goethe-Universität, Max von Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Senada Nozinovic
- Institute of Organic Chemistry and Chemical Biology, BMRZ, Johann Wolfgang Goethe-Universität, Max von Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Anke Reining
- Institute of Organic Chemistry and Chemical Biology, BMRZ, Johann Wolfgang Goethe-Universität, Max von Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Harald Schwalbe
- Institute of Organic Chemistry and Chemical Biology, BMRZ, Johann Wolfgang Goethe-Universität, Max von Laue-Straße 7, 60438 Frankfurt am Main, Germany.
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48
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Matzner D, Mayer G. (Dis)similar Analogues of Riboswitch Metabolites as Antibacterial Lead Compounds. J Med Chem 2015; 58:3275-86. [PMID: 25603286 DOI: 10.1021/jm500868e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The rise of antimicrobial resistance in human pathogenic bacteria has increased the necessity for the discovery of novel, yet unexplored antibacterial drug targets. Riboswitches, which are embedded in untranslated regions of bacterial messenger RNA (mRNA), represent such an interesting target structure. These RNA elements regulate gene expression upon binding to natural metabolites, second messengers, and inorganic ions, such as fluoride with high affinity and in a highly discriminative manner. Recently, efforts have been directed toward the identification of artificial riboswitch activators by establishing high-throughput screening assays, fragment-based screening, and structure-guided ligand design approaches. Emphasis in this review is placed on the special requirements and synthesis of new potential antibiotic drugs that target riboswitches in which dissimilarity is an important aspect in the design of potential lead compounds.
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Affiliation(s)
- Daniel Matzner
- Life and Medical Sciences Institute, University of Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - Günter Mayer
- Life and Medical Sciences Institute, University of Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
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49
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Rinnenthal J, Wagner D, Marquardsen T, Krahn A, Engelke F, Schwalbe H. A temperature-jump NMR probe setup using rf heating optimized for the analysis of temperature-induced biomacromolecular kinetic processes. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 251:84-93. [PMID: 25616187 DOI: 10.1016/j.jmr.2014.11.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 11/24/2014] [Accepted: 11/25/2014] [Indexed: 06/04/2023]
Abstract
A novel temperature jump (T-jump) probe operational at B(0) fields of 600 MHz (14.1 Tesla) with an integrated cage radio-frequency (rf) coil for rapid (<1 s) heating in high-resolution (HR) liquid-state NMR-spectroscopy is presented and its performance investigated. The probe consists of an inner 2.5 mm "heating coil" designed for generating rf-electric fields of 190-220 MHz across a lossy dielectric sample and an outer two coil assembly for (1)H-, (2)H- and (15)N-nuclei. High B(0) field homogeneities (0.7 Hz at 600 MHz) are combined with high heating rates (20-25 K/s) and only small temperature gradients (<±1.5 K, 3s after 20 K T-jump). The heating coil is under control of a high power rf-amplifier within the NMR console and can therefore easily be accessed by the pulse programmer. Furthermore, implementation of a real-time setup including synchronization of the NMR spectrometer's air flow heater with the rf-heater used to maintain the temperature of the sample is described. Finally, the applicability of the real-time T-jump setup for the investigation of biomolecular kinetic processes in the second-to-minute timescale is demonstrated for samples of a model 14mer DNA hairpin and a (15)N-selectively labeled 40nt hsp17-RNA thermometer.
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Affiliation(s)
- Jörg Rinnenthal
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, Max-von-Laue-Strasse 7, D-60438 Frankfurt/Main, Germany
| | - Dominic Wagner
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, Max-von-Laue-Strasse 7, D-60438 Frankfurt/Main, Germany
| | | | - Alexander Krahn
- Bruker BioSpin GmbH, Am Silberstreifen, 76287 Rheinstetten, Germany
| | - Frank Engelke
- Bruker BioSpin GmbH, Am Silberstreifen, 76287 Rheinstetten, Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-University, Max-von-Laue-Strasse 7, D-60438 Frankfurt/Main, Germany.
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50
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Moschen T, Wunderlich CH, Spitzer R, Levic J, Micura R, Tollinger M, Kreutz C. Ligand-detected relaxation dispersion NMR spectroscopy: dynamics of preQ1-RNA binding. Angew Chem Int Ed Engl 2015; 54:560-3. [PMID: 25403518 PMCID: PMC4353840 DOI: 10.1002/anie.201409779] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Indexed: 12/21/2022]
Abstract
An NMR-based approach to characterizing the binding kinetics of ligand molecules to biomolecules, like RNA or proteins, by ligand-detected Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion experiments is described. A (15)N-modified preQ1 ligand is used to acquire relaxation dispersion experiments in the presence of low amounts of the Fsu class I preQ1 aptamer RNA, and increasing ligand concentrations to probe the RNA small molecule interaction. Our experimental data strongly support the conformational selection mechanism postulated. The approach gives direct access to two parameters of a ligand-receptor interaction: the off rate and the population of the small molecule-receptor complex. A detailed description of the kinetics underlying the ligand binding process is of crucial importance to fully understanding a riboswitch's function and to evaluate potential new antibiotics candidates targeting the noncoding RNA species. Ligand-detected NMR relaxation dispersion experiments represent a valuable diagnostic tool for the characterization of binding mechanisms.
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Affiliation(s)
- Thomas Moschen
- Institute of Organic Chemistry, Centre for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria)
| | - Christoph Hermann Wunderlich
- Institute of Organic Chemistry, Centre for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria)
| | - Romana Spitzer
- Institute of Organic Chemistry, Centre for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria)
| | - Jasmin Levic
- Institute of Organic Chemistry, Centre for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria)
| | - Ronald Micura
- Institute of Organic Chemistry, Centre for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria)
| | - Martin Tollinger
- Institute of Organic Chemistry, Centre for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria)
| | - Christoph Kreutz
- Institute of Organic Chemistry, Centre for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria)
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