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Mukherjee D, Maiti S, Gouda PK, Sharma R, Roy P, Bhattacharyya D. RNABPDB: Molecular Modeling of RNA Structure-From Base Pair Analysis in Crystals to Structure Prediction. Interdiscip Sci 2022; 14:759-774. [PMID: 35705797 DOI: 10.1007/s12539-022-00528-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 05/05/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
The stable three-dimensional structure of RNA is known to play several important biochemical roles, from post-transcriptional gene regulation to enzymatic action. These structures contain double-helical regions, which often have different types of non-canonical base pairs in addition to Watson-Crick base pairs. Hence, it is important to study their structures from experimentally obtained or even predicted ones, to understand their role, or to develop a drug against the potential targets. Molecular Modeling of RNA double helices containing non-canonical base pairs is a difficult process, particularly due to the unavailability of structural features of non-Watson-Crick base pairs. Here we show a composite web-server with an associated database that allows one to generate the structure of RNA double helix containing non-canonical base pairs using consensus parameters obtained from the database. The database classification is followed by an evaluation of the central tendency of the structural parameters as well as a quantitative estimation of interaction strengths. These parameters are used to construct three-dimensional structures of double helices composed of Watson-Crick and/or non-canonical base pairs. Our benchmark study to regenerate double-helical fragments of many experimentally derived RNA structures indicate very high accuracy. This composite server is expected to be highly useful in understanding functions of various pre-miRNA by modeling structures of the molecules and estimating binding efficiency. The database can be accessed from http://hdrnas.saha.ac.in/rnabpdb .
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Affiliation(s)
- Debasish Mukherjee
- Computational Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700064, India.
- Institute of Molecular Biology gGmbH (IMB), Ackermannweg 4, 55128, Mainz, Germany.
| | - Satyabrata Maiti
- Computational Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700064, India
- Homi Bhaba National Institute, Anushaktinagar, Mumbai, 400094, India
| | - Prasanta Kumar Gouda
- Computational Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700064, India
| | - Richa Sharma
- Computational Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700064, India
| | - Parthajit Roy
- Department of Computer Science, The University of Burdwan, Golapbag, Burdwan, 713104, India
| | - Dhananjay Bhattacharyya
- Computational Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700064, India
- Homi Bhaba National Institute, Anushaktinagar, Mumbai, 400094, India
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2
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Olson WK, Li S, Kaukonen T, Colasanti AV, Xin Y, Lu XJ. Effects of Noncanonical Base Pairing on RNA Folding: Structural Context and Spatial Arrangements of G·A Pairs. Biochemistry 2019; 58:2474-2487. [PMID: 31008589 PMCID: PMC6729125 DOI: 10.1021/acs.biochem.9b00122] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Noncanonical base pairs play important roles in assembling the three-dimensional structures critical to the diverse functions of RNA. These associations contribute to the looped segments that intersperse the canonical double-helical elements within folded, globular RNA molecules. They stitch together various structural elements, serve as recognition elements for other molecules, and act as sites of intrinsic stiffness or deformability. This work takes advantage of new software (DSSR) designed to streamline the analysis and annotation of RNA three-dimensional structures. The multiscale structural information gathered for individual molecules, combined with the growing number of unique, well-resolved RNA structures, makes it possible to examine the collective features deeply and to uncover previously unrecognized patterns of chain organization. Here we focus on a subset of noncanonical base pairs involving guanine and adenine and the links between their modes of association, secondary structural context, and contributions to tertiary folding. The rigorous descriptions of base-pair geometry that we employ facilitate characterization of recurrent geometric motifs and the structural settings in which these arrangements occur. Moreover, the numerical parameters hint at the natural motions of the interacting bases and the pathways likely to connect different spatial forms. We draw attention to higher-order multiplexes involving two or more G·A pairs and the roles these associations appear to play in bridging different secondary structural units. The collective data reveal pairing propensities in base organization, secondary structural context, and deformability and serve as a starting point for further multiscale investigations and/or simulations of RNA folding.
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Affiliation(s)
- Wilma K. Olson
- Department of Chemistry & Chemical Biology and Center for Quantitative Biology, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Shuxiang Li
- Department of Chemistry & Chemical Biology and Center for Quantitative Biology, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Thomas Kaukonen
- Department of Chemistry & Chemical Biology and Center for Quantitative Biology, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Andrew V. Colasanti
- Department of Chemistry & Chemical Biology and Center for Quantitative Biology, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Yurong Xin
- Department of Chemistry & Chemical Biology and Center for Quantitative Biology, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Xiang-Jun Lu
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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3
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Alcolea Palafox M. Effect of the sulfur atom on S2 and S4 positions of the uracil ring in different DNA:RNA hybrid microhelixes with three nucleotide base pairs. Biopolymers 2019; 110:e23247. [PMID: 30676643 DOI: 10.1002/bip.23247] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/03/2018] [Accepted: 11/07/2018] [Indexed: 02/06/2023]
Abstract
The effect of the sulphur atom on the uracil ring was analyzed in different DNA:RNA microhelixes with three nucleotide base-pairs, including uridine, 2-thiouridine, 4-thiouridine, 2,4-dithiouridine, cytidine, adenosine and guanosine. Distinct backbone and helical parameters were optimized at different density functional (DFT) levels. The Watson-Crick pair with 2-thiouridine appears weaker than with uridine, but its interaction with water molecules appears easier. Two types of microhelixes were found, depending on the H-bond of H2' hydroxyl atom: A-type appears with the ribose ring in 3 E-envelope C3' -endo, and B-type in 2 E-envelope C2' -endo. B-type is less common but it is more stable and with higher dipole-moment. The sulphur atoms significantly increase the dipole-moment of the microhelix, as well as the rise and propeller twist parameters. Simulations with four Na atoms H-bonded to the phosphate groups, and further hydration with explicit water molecules were carried out. A re-definition of the numerical value calculation of several base-pair and base-stacking parameters is suggested.
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Affiliation(s)
- Mauricio Alcolea Palafox
- Departamento de Química-Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain
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4
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Design of a fused triazolyl 2-quinolinone unnatural nucleoside via tandem CuAAC-Ullmann coupling reaction and study of photophysical property. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.03.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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5
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Voltz K, Léonard J, Touceda PT, Conyard J, Chaker Z, Dejaegere A, Godet J, Mély Y, Haacke S, Stote RH. Quantitative sampling of conformational heterogeneity of a DNA hairpin using molecular dynamics simulations and ultrafast fluorescence spectroscopy. Nucleic Acids Res 2016; 44:3408-19. [PMID: 26896800 PMCID: PMC4838372 DOI: 10.1093/nar/gkw077] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 01/29/2016] [Indexed: 01/22/2023] Open
Abstract
Molecular dynamics (MD) simulations and time resolved fluorescence (TRF) spectroscopy were combined to quantitatively describe the conformational landscape of the DNA primary binding sequence (PBS) of the HIV-1 genome, a short hairpin targeted by retroviral nucleocapsid proteins implicated in the viral reverse transcription. Three 2-aminopurine (2AP) labeled PBS constructs were studied. For each variant, the complete distribution of fluorescence lifetimes covering 5 orders of magnitude in timescale was measured and the populations of conformers experimentally observed to undergo static quenching were quantified. A binary quantification permitted the comparison of populations from experimental lifetime amplitudes to populations of aromatically stacked 2AP conformers obtained from simulation. Both populations agreed well, supporting the general assumption that quenching of 2AP fluorescence results from pi-stacking interactions with neighboring nucleobases and demonstrating the success of the proposed methodology for the combined analysis of TRF and MD data. Cluster analysis of the latter further identified predominant conformations that were consistent with the fluorescence decay times and amplitudes, providing a structure-based rationalization for the wide range of fluorescence lifetimes. Finally, the simulations provided evidence of local structural perturbations induced by 2AP. The approach presented is a general tool to investigate fine structural heterogeneity in nucleic acid and nucleoprotein assemblies.
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Affiliation(s)
- Karine Voltz
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de Santé et de Recherche Médicale (INSERM) U964, Centre National de Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - Jérémie Léonard
- Institut de Physique et Chimie des Matériaux de Strasbourg & Labex NIE, CNRS UMR 7504, Université de Strasbourg, Strasbourg, France
| | - Patricia Tourón Touceda
- Institut de Physique et Chimie des Matériaux de Strasbourg & Labex NIE, CNRS UMR 7504, Université de Strasbourg, Strasbourg, France
| | - Jamie Conyard
- Institut de Physique et Chimie des Matériaux de Strasbourg & Labex NIE, CNRS UMR 7504, Université de Strasbourg, Strasbourg, France
| | - Ziyad Chaker
- Institut de Physique et Chimie des Matériaux de Strasbourg & Labex NIE, CNRS UMR 7504, Université de Strasbourg, Strasbourg, France
| | - Annick Dejaegere
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de Santé et de Recherche Médicale (INSERM) U964, Centre National de Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - Julien Godet
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch Cedex, France
| | - Yves Mély
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch Cedex, France
| | - Stefan Haacke
- Institut de Physique et Chimie des Matériaux de Strasbourg & Labex NIE, CNRS UMR 7504, Université de Strasbourg, Strasbourg, France
| | - Roland H Stote
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de Santé et de Recherche Médicale (INSERM) U964, Centre National de Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France
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6
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Parker TM, Sherrill CD. Assessment of Empirical Models versus High-Accuracy Ab Initio Methods for Nucleobase Stacking: Evaluating the Importance of Charge Penetration. J Chem Theory Comput 2015; 11:4197-204. [DOI: 10.1021/acs.jctc.5b00588] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Trent M. Parker
- Center for Computational
Molecular Science and Technology, School of Chemistry and Biochemistry,
and School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
| | - C. David Sherrill
- Center for Computational
Molecular Science and Technology, School of Chemistry and Biochemistry,
and School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
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7
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McDonald AR, Denning EJ, MacKerell AD. Impact of geometry optimization on base-base stacking interaction energies in the canonical A- and B-forms of DNA. J Phys Chem A 2013; 117:1560-8. [PMID: 23343365 DOI: 10.1021/jp308364d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Base stacking is known to make an important contribution to the stability of DNA and RNA, and accordingly, significant efforts are ongoing to calculate stacking energies using ab initio quantum mechanical methods. To date, impressive improvements have been made in the model chemistries used to perform stacking energy calculations, including extensions that include robust treatments of electron correlation with extended basis sets, as required to treat interactions where dispersion makes a significant contribution. However, those efforts typically use rigid monomer geometries when calculating the interaction energies. To overcome this, in the present work, we describe a novel internal coordinate definition that allows the relative, intermolecular orientation of stacked base monomers to be constrained during geometry optimizations while allowing full optimization of the intramolecular degrees of freedom. Use of the novel reference frame to calculate the impact of full geometry optimization versus constraining the bases to be planar on base monomer stacking energies, combined with density-fitted, spin-component scaling MP2 treatment of electron correlation, shows that full optimization makes the average stacking energy more favorable by -3.4 and -1.5 kcal/mol for the canonical A and B conformations of the 16 5' to 3' base stacked monomers. Thus, treatment of geometry optimization impacts the stacking energies to an extent similar to or greater than the impact of current state of the art increases in the rigor of the model chemistry itself used to treat base stacking. Results also indicate that stacking favors the B-form of DNA, though the average difference versus the A-form decreases from -2.6 to -0.6 kcal/mol when the intramolecular geometry is allowed to fully relax. However, stacking involving cytosine is shown to favor the A-form of DNA, with that contribution generally larger in the fully optimized bases. The present results show the importance of allowing geometry optimization, as well as properly treating the appropriate model chemistry, in studies of nucleic acid base stacking.
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Affiliation(s)
- Ashley Ringer McDonald
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201, USA
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8
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Pasi M, Lavery R, Ceres N. PaLaCe: A Coarse-Grain Protein Model for Studying Mechanical Properties. J Chem Theory Comput 2012; 9:785-93. [DOI: 10.1021/ct3007925] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Marco Pasi
- Bases Moléculaires
et Structurales des Systèmes
Infectieux, Univ. Lyon I/CNRS UMR 5086, IBCP, 7 Passage du Vercors,
69367 Lyon, France
| | - Richard Lavery
- Bases Moléculaires
et Structurales des Systèmes
Infectieux, Univ. Lyon I/CNRS UMR 5086, IBCP, 7 Passage du Vercors,
69367 Lyon, France
| | - Nicoletta Ceres
- Bases Moléculaires
et Structurales des Systèmes
Infectieux, Univ. Lyon I/CNRS UMR 5086, IBCP, 7 Passage du Vercors,
69367 Lyon, France
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9
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Berlin YA, Voityuk AA, Ratner MA. DNA base pair stacks with high electric conductance: a systematic structural search. ACS NANO 2012; 6:8216-8225. [PMID: 22901272 DOI: 10.1021/nn3030139] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report a computational search for DNA π-stack structures exhibiting high electric conductance in the hopping regime, based on the INDO/S calculations of electronic coupling and the method of data analysis called k-means clustering. Using homogeneous poly(G)-poly(C) and poly(A)-poly(T) stacks as the simplest structural models, we identify the configurations of neighboring G:C and A:T pairs that allow strong electronic coupling and, therefore, molecular electric conductance much larger than the values reported for the corresponding reference systems in the literature. A computational approach for modeling the impact of thermal fluctuations on the averaged dimer structure was also proposed and applied to the [(G:C),(G:C)] and [(A:T),(A:T)] duplexes. The results of this work may provide guidance for the construction of DNA devices and DNA-based elements of nanoscale molecular circuits. Several factors that cause changes of step parameters favorable to the formation of the predicted stack conformation with high electric conductance of DNA molecules are also discussed; favorable geometries may enhance the conductivity by factors as large as 15.
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Affiliation(s)
- Yuri A Berlin
- Department of Chemistry, Northwestern University, 1145 Sheridan Road, Evanston, Illinois 60208-3113, United States
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10
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Wolfe KC, Hastings WA, Dutta S, Long A, Shapiro BA, Woolf TB, Guthold M, Chirikjian GS. Multiscale modeling of double-helical DNA and RNA: a unification through Lie groups. J Phys Chem B 2012; 116:8556-72. [PMID: 22676719 PMCID: PMC4833121 DOI: 10.1021/jp2126015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Several different mechanical models of double-helical nucleic-acid structures that have been presented in the literature are reviewed here together with a new analysis method that provides a reconciliation between these disparate models. In all cases, terminology and basic results from the theory of Lie groups are used to describe rigid-body motions in a coordinate-free way, and when necessary, coordinates are introduced in a way in which simple equations result. We consider double-helical DNAs and RNAs which, in their unstressed referential state, have backbones that are either straight, slightly precurved, or bent by the action of a protein or other bound molecule. At the coarsest level, we consider worm-like chains with anisotropic bending stiffness. Then, we show how bi-rod models converge to this for sufficiently long filament lengths. At a finer level, we examine elastic networks of rigid bases and show how these relate to the coarser models. Finally, we show how results from molecular dynamics simulation at full atomic resolution (which is the finest scale considered here) and AFM experimental measurements (which is at the coarsest scale) relate to these models.
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Affiliation(s)
- Kevin C. Wolfe
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland, United States
| | | | - Samrat Dutta
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina, United States
| | - Andrew Long
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Bruce A. Shapiro
- Center for Cancer Research Nanobiology Program, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, Maryland, United States
| | - Thomas B. Woolf
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Martin Guthold
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina, United States
| | - Gregory S. Chirikjian
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland, United States
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11
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Lavery R, Moakher M, Maddocks JH, Petkeviciute D, Zakrzewska K. Conformational analysis of nucleic acids revisited: Curves+. Nucleic Acids Res 2009; 37:5917-29. [PMID: 19625494 PMCID: PMC2761274 DOI: 10.1093/nar/gkp608] [Citation(s) in RCA: 577] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We describe Curves+, a new nucleic acid conformational analysis program which is applicable to a wide range of nucleic acid structures, including those with up to four strands and with either canonical or modified bases and backbones. The program is algorithmically simpler and computationally much faster than the earlier Curves approach, although it still provides both helical and backbone parameters, including a curvilinear axis and parameters relating the position of the bases to this axis. It additionally provides a full analysis of groove widths and depths. Curves+ can also be used to analyse molecular dynamics trajectories. With the help of the accompanying program Canal, it is possible to produce a variety of graphical output including parameter variations along a given structure and time series or histograms of parameter variations during dynamics.
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Affiliation(s)
- R Lavery
- Institut de Biologie et Chimie des Protéines, CNRS UMR 5086/Université de Lyon, 7 Passage du Vercors, 69367 Lyon, France.
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12
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New information content in RNA base pairing deduced from quantitative analysis of high-resolution structures. Methods 2009; 47:177-86. [PMID: 19150407 DOI: 10.1016/j.ymeth.2008.12.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Revised: 12/03/2008] [Accepted: 12/15/2008] [Indexed: 11/23/2022] Open
Abstract
Non-canonical base pairs play important roles in organizing the complex three-dimensional folding of RNA. Here, we outline methodology developed both to analyze the spatial patterns of interacting base pairs in known RNA structures and to reconstruct models from the collective experimental information. We focus attention on the structural context and deformability of the seven pairing patterns found in greatest abundance in the helical segments in a set of well-resolved crystal structures, including (i-ii) the canonical A.U and G.C Watson-Crick base pairs, (iii) the G.U wobble pair, (iv) the sheared G.A pair, (v) the A.U Hoogsteen pair, (vi) the U.U wobble pair, and (vii) the G.A Watson-Crick-like pair. The non-canonical pairs stand out from the canonical associations in terms of apparent deformability, spanning a broader range of conformational states as measured by the six rigid-body parameters used to describe the spatial arrangements of the interacting bases, the root-mean-square deviations of the base-pair atoms, and the fluctuations in hydrogen-bonding geometry. The deformabilties, the modes of base-pair deformation, and the preferred sites of occurrence depend on sequence. We also characterize the positioning and overlap of the base pairs with respect to the base pairs that stack immediately above and below them in double-helical fragments. We incorporate the observed positions of the bases, base pairs, and intervening phosphorus atoms in models to predict the effects of the non-canonical interactions on overall helical structure.
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13
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Ouyang D, Zhang H, Herten DP, Parekh HS, Smith SC. Flexibility of Short-Strand RNA in Aqueous Solution as Revealed by Molecular Dynamics Simulation: Are A-RNA and A´-RNA Distinct Conformational Structures? Aust J Chem 2009. [DOI: 10.1071/ch09090] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We use molecular dynamics simulations to compare the conformational structure and dynamics of a 21-base pair RNA sequence initially constructed according to the canonical A-RNA and A′-RNA forms in the presence of counterions and explicit water. Our study aims to add a dynamical perspective to the solid-state structural information that has been derived from X-ray data for these two characteristic forms of RNA. Analysis of the three main structural descriptors commonly used to differentiate between the two forms of RNA – namely major groove width, inclination and the number of base pairs in a helical twist – over a 30 ns simulation period reveals a flexible structure in aqueous solution with fluctuations in the values of these structural parameters encompassing the range between the two crystal forms and more. This provides evidence to suggest that the identification of distinct A-RNA and A′-RNA structures, while relevant in the crystalline form, may not be generally relevant in the context of RNA in the aqueous phase. The apparent structural flexibility observed in our simulations is likely to bear ramifications for the interactions of RNA with biological molecules (e.g. proteins) and non-biological molecules (e.g. non-viral gene delivery vectors).
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14
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Swigon D, Olson WK. Mesoscale modeling of multi-protein-DNA assemblies: the role of the catabolic activator protein in Lac-repressor-mediated looping. INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS 2008; 43:1082-1093. [PMID: 23874000 PMCID: PMC3715064 DOI: 10.1016/j.ijnonlinmec.2008.07.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
DNA looping plays a key role in the regulation of the lac operon in Escherichia coli. The presence of a tightly bent loop (between sequentially distant sites of Lac repressor protein binding) purportedly hinders the binding of RNA polymerase and subsequent transcription of the genetic message. The unexpectedly favorable binding interaction of this protein-DNA assembly with the catabolic activator protein (CAP), a protein that also bends DNA and paradoxically facilitates the binding of RNA polymerase, stimulated extension of our base-pair level theory of DNA elasticity to the treatment of DNA loops formed in the presence of several proteins. Here we describe in detail a procedure to determine the structures and free energies of multi-protein-DNA assemblies and illustrate the predicted effects of CAP binding on the configurations of the wild-type 92-bp Lac repressor-mediated O3-O1 DNA loop. We show that the DNA loop adopts an antiparallel orientation in the most likely structure and that this loop accounts for the published experimental observation that, when CAP is bound to the loop, one of the arms of LacR binds to an alternative site that is displaced from the original site by 5 bp.
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Affiliation(s)
- David Swigon
- Department of Mathematics, University of Pittsburgh, Pittsburgh, PA 15260
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15
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Abraham M, Dror O, Nussinov R, Wolfson HJ. Analysis and classification of RNA tertiary structures. RNA (NEW YORK, N.Y.) 2008; 14:2274-89. [PMID: 18824509 PMCID: PMC2578864 DOI: 10.1261/rna.853208] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Accepted: 07/05/2008] [Indexed: 05/19/2023]
Abstract
There is a fast growing interest in noncoding RNA transcripts. These transcripts are not translated into proteins, but play essential roles in many cellular and pathological processes. Recent efforts toward comprehension of their function has led to a substantial increase in both the number and the size of solved RNA structures. With the aim of addressing questions relating to RNA structural diversity, we examined RNA conservation at three structural levels: primary, secondary, and tertiary structure. Additionally, we developed an automated method for classifying RNA structures based on spatial (three-dimensional [3D]) similarity. Applying the method to all solved RNA structures resulted in a classified database of RNA tertiary structures (DARTS). DARTS embodies 1333 solved RNA structures classified into 94 clusters. The classification is hierarchical, reflecting the structural relationship between and within clusters. We also developed an application for searching DARTS with a new structure. The search is fast and its performance was successfully tested on all solved RNA structures since the creation of DARTS. A user-friendly interface for both the database and the search application is available online. We show intracluster and intercluster similarities in DARTS and demonstrate the usefulness of the search application. The analysis reveals the current structural repertoire of RNA and exposes common global folds and local tertiary motifs. Further study of these conserved substructures may suggest possible RNA domains and building blocks. This should be beneficial for structure prediction and for gaining insights into structure-function relationships.
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Affiliation(s)
- Mira Abraham
- School of Computer Science, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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16
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Wynveen A, Lee DJ, Kornyshev AA, Leikin S. Helical coherence of DNA in crystals and solution. Nucleic Acids Res 2008; 36:5540-51. [PMID: 18755709 PMCID: PMC2553576 DOI: 10.1093/nar/gkn514] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Revised: 06/25/2008] [Accepted: 07/28/2008] [Indexed: 11/15/2022] Open
Abstract
The twist, rise, slide, shift, tilt and roll between adjoining base pairs in DNA depend on the identity of the bases. The resulting dependence of the double helix conformation on the nucleotide sequence is important for DNA recognition by proteins, packaging and maintenance of genetic material, and other interactions involving DNA. This dependence, however, is obscured by poorly understood variations in the stacking geometry of the same adjoining base pairs within different sequence contexts. In this article, we approach the problem of sequence-dependent DNA conformation by statistical analysis of X-ray and NMR structures of DNA oligomers. We evaluate the corresponding helical coherence length--a cumulative parameter quantifying sequence-dependent deviations from the ideal double helix geometry. We find, e.g. that the solution structure of synthetic oligomers is characterized by 100-200 A coherence length, which is similar to approximately 150 A coherence length of natural, salmon-sperm DNA. Packing of oligomers in crystals dramatically alters their helical coherence. The coherence length increases to 800-1200 A, consistent with its theoretically predicted role in interactions between DNA at close separations.
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Affiliation(s)
- Aaron Wynveen
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany, Department of Chemistry, Faculty of Natural Sciences, Imperial College London, SW7 2AZ London, UK, Max-Planck-Institut für Physik Komplexer Systeme, Nöthnizer Straße 38, D-01187 Dresden, Germany and Section of Physical Biochemistry, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD 20892, USA
| | - Dominic J. Lee
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany, Department of Chemistry, Faculty of Natural Sciences, Imperial College London, SW7 2AZ London, UK, Max-Planck-Institut für Physik Komplexer Systeme, Nöthnizer Straße 38, D-01187 Dresden, Germany and Section of Physical Biochemistry, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD 20892, USA
| | - Alexei A. Kornyshev
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany, Department of Chemistry, Faculty of Natural Sciences, Imperial College London, SW7 2AZ London, UK, Max-Planck-Institut für Physik Komplexer Systeme, Nöthnizer Straße 38, D-01187 Dresden, Germany and Section of Physical Biochemistry, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD 20892, USA
| | - Sergey Leikin
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany, Department of Chemistry, Faculty of Natural Sciences, Imperial College London, SW7 2AZ London, UK, Max-Planck-Institut für Physik Komplexer Systeme, Nöthnizer Straße 38, D-01187 Dresden, Germany and Section of Physical Biochemistry, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD 20892, USA
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17
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Cheatham TE, Brooks BR, Kollman PA. Molecular modeling of nucleic acid structure. ACTA ACUST UNITED AC 2008; Chapter 7:Unit 7.5. [PMID: 18428873 DOI: 10.1002/0471142700.nc0705s06] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This unit is the first in a series of four units covering the analysis of nucleic acid structure by molecular modeling. This unit provides an overview of computer simulation of nucleic acids. Topics include the static structure model, computational graphics and energy models, generation of an initial model, and characterization of the overall three-dimensional structure.
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Affiliation(s)
- T E Cheatham
- National Heart, Lung and Blood Institute, NIH, Bethesda, Maryland, USA
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18
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Voityuk AA. Conformations of poly{G}-poly{C} pi stacks with high hole mobility. J Chem Phys 2008; 128:045104. [PMID: 18248011 DOI: 10.1063/1.2823015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Charge transfer properties of DNA depend strongly on the pi stack conformation. In the present paper, we identify conformations of homogeneous poly-{G}-poly-{C} stacks that should exhibit high charge mobility. Two different computational approaches were applied. First, we calculated the electronic coupling squared, V(2), between adjacent base pairs for all 1 ps snapshots extracted from 15 ns molecular dynamics trajectory of the duplex G(15). The average value of the coupling squared <V(2)> is found to be 0.0065 eV(2). Then we analyze the base-pair and step parameters of the configurations in which V(2) is at least an order of magnitude larger than <V(2)>. To obtain more consistent data, approximately 65,000 configurations of the (G:C)(2) stack were built using systematic screening of the step parameters shift, slide, and twist. We show that undertwisted structures (twist<20 degrees) are of special interest, because the pi stack conformations with strong electronic couplings are found for a wide range of slide and shift. Although effective hole transfer can also occur in configurations with twist=30 degrees and 35 degrees, large mutual displacements of neighboring base pairs are required for that. Overtwisted conformation (twist> or =38 degrees) seems to be of limited interest in the context of effective hole transfer. The results may be helpful in the search for DNA based elements for nanoelectronics.
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19
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Lu XJ, Olson WK. 3DNA: a versatile, integrated software system for the analysis, rebuilding and visualization of three-dimensional nucleic-acid structures. Nat Protoc 2008; 3:1213-27. [PMID: 18600227 PMCID: PMC3065354 DOI: 10.1038/nprot.2008.104] [Citation(s) in RCA: 481] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We present a set of protocols showing how to use the 3DNA suite of programs to analyze, rebuild and visualize three-dimensional nucleic-acid structures. The software determines a wide range of conformational parameters, including the identities and rigid-body parameters of interacting bases and base-pair steps, the nucleotides comprising helical fragments, the area of overlap of stacked bases and so on. The reconstruction of three-dimensional structure takes advantage of rigorously defined rigid-body parameters, producing rectangular block representations of the nucleic-acid bases and base pairs and all-atom models with approximate sugar-phosphate backbones. The visualization components create vector-based drawings and scenes that can be rendered as raster-graphics images, allowing for easy generation of publication-quality figures. The utility programs use geometric variables to control the view and scale of an object, for comparison of related structures. The commands run in seconds even for large structures. The software and related information are available at http://3dna.rutgers.edu/.
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Affiliation(s)
- Xiang-Jun Lu
- Department of Chemistry and Chemical Biology and BioMaPS Institute for Quantitative Biology, Rutgers-The State University of New Jersey, Piscataway, New Jersey 08854-8087, USA.
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20
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Dror O, Nussinov R, Wolfson HJ. The ARTS web server for aligning RNA tertiary structures. Nucleic Acids Res 2006; 34:W412-5. [PMID: 16845038 PMCID: PMC1538835 DOI: 10.1093/nar/gkl312] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 03/06/2006] [Accepted: 04/11/2006] [Indexed: 11/12/2022] Open
Abstract
RNA molecules with common structural features may share similar functional properties. Structural comparison of RNAs and detection of common substructures is, thus, a highly important task. Nevertheless, the current available tools in the RNA community provide only a partial solution, since they either work at the 2D level or are suitable for detecting predefined or local contiguous tertiary motifs only. Here, we describe a web server built around ARTS, a method for aligning tertiary structures of nucleic acids (both RNA and DNA). ARTS receives a pair of 3D nucleic acid structures and searches for a priori unknown common substructures. The search is truly 3D and irrespective of the order of the nucleotides on the chain. The identified common substructures can be large global folds with hundreds and even thousands of nucleotides as well as small local motifs with at least two successive base pairs. The method is highly efficient and has been used to conduct an all-against-all comparison of all the RNA structures in the Protein Data Bank. The web server together with a software package for download are freely accessible at http://bioinfo3d.cs.tau.ac.il/ARTS.
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Affiliation(s)
- Oranit Dror
- School of Computer Science, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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21
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Beveridge DL, Barreiro G, Byun KS, Case DA, Cheatham TE, Dixit SB, Giudice E, Lankas F, Lavery R, Maddocks JH, Osman R, Seibert E, Sklenar H, Stoll G, Thayer KM, Varnai P, Young MA. Molecular dynamics simulations of the 136 unique tetranucleotide sequences of DNA oligonucleotides. I. Research design and results on d(CpG) steps. Biophys J 2004; 87:3799-813. [PMID: 15326025 PMCID: PMC1304892 DOI: 10.1529/biophysj.104.045252] [Citation(s) in RCA: 218] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Accepted: 08/03/2004] [Indexed: 11/18/2022] Open
Abstract
We describe herein a computationally intensive project aimed at carrying out molecular dynamics (MD) simulations including water and counterions on B-DNA oligomers containing all 136 unique tetranucleotide base sequences. This initiative was undertaken by an international collaborative effort involving nine research groups, the "Ascona B-DNA Consortium" (ABC). Calculations were carried out on the 136 cases imbedded in 39 DNA oligomers with repeating tetranucleotide sequences, capped on both ends by GC pairs and each having a total length of 15 nucleotide pairs. All MD simulations were carried out using a well-defined protocol, the AMBER suite of programs, and the parm94 force field. Phase I of the ABC project involves a total of approximately 0.6 mus of simulation for systems containing approximately 24,000 atoms. The resulting trajectories involve 600,000 coordinate sets and represent approximately 400 gigabytes of data. In this article, the research design, details of the simulation protocol, informatics issues, and the organization of the results into a web-accessible database are described. Preliminary results from 15-ns MD trajectories are presented for the d(CpG) step in its 10 unique sequence contexts, and issues of stability and convergence, the extent of quasiergodic problems, and the possibility of long-lived conformational substates are discussed.
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Affiliation(s)
- David L Beveridge
- Chemistry Department, Molecular Biology & Biochemistry Department, and Molecular Biophysics Program, Wesleyan University, Middletown, Connecticut 06459, USA.
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22
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Olson WK, Swigon D, Coleman BD. Implications of the dependence of the elastic properties of DNA on nucleotide sequence. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2004; 362:1403-1422. [PMID: 15306458 DOI: 10.1098/rsta.2004.1380] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Recent advances in structural biochemistry have provided evidence that not only the geometric properties but also the elastic moduli of duplex DNA are strongly dependent on nucleotide sequence in a way that is not accounted for by classical rod models of the Kirchhoff type. A theory of sequence-dependent DNA elasticity is employed here to calculate the dependence of the equilibrium configurations of circular DNA on the binding of ligands that can induce changes in intrinsic twist at a single base-pair step. Calculations are presented of the influence on configurations of the assumed values and distribution along the DNA of intrinsic roll and twist and a modulus coupling roll to twist. Among the results obtained are the following. For minicircles formed from intrinsically straight DNA, the distribution of roll-twist coupling strongly affects the dependence of the total elastic energy Psi on the amount alpha of imposed untwisting, and that dependence can be far from quadratic. (In fact, for a periodic distribution of roll-twist coupling with a period equal to the intrinsic helical repeat length, Psi can be essentially independent of alpha for -90 degrees < alpha <90 degrees.) When the minicircle is homogeneous and without roll-twist coupling, but with uniform positive intrinsic roll, the point at which Psi attains its minimum value shifts towards negative values of alpha. It is remarked that there are cases in which one can relate graphs of Psi versus alpha to the 'effective values' of bending and twisting moduli and helical repeat length obtained from measurements of equilibrium distributions of topoisomers and probabilities of ring closure. For a minicircle formed from DNA that has an 'S' shape when stress-free, the graphs of Psi versus alpha have maxima at alpha = 0. As the binding of a twisting agent to such a minicircle results in a net decrease in Psi, the affinity of the twisting agent for binding to the minicircle is greater than its affinity for binding to unconstrained DNA with the same sequence.
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Affiliation(s)
- Wilma K Olson
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, NJ 08854-8087, USA.
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23
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Wu B, Girard F, van Buuren B, Schleucher J, Tessari M, Wijmenga S. Global structure of a DNA three-way junction by solution NMR: towards prediction of 3H fold. Nucleic Acids Res 2004; 32:3228-39. [PMID: 15199171 PMCID: PMC434450 DOI: 10.1093/nar/gkh645] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Three-way junctions (3H) are the simplest and most commonly occurring branched nucleic acids. They consist of three double helical arms (A to C), connected at the junction point, with or without a number of unpaired bases in one or more of the three different strands. Three-way junctions with two unpaired bases in one strand (3HS2) have a high tendency to adopt either of two alternative stacked conformations in which two of the three arms A, B and C are coaxially stacked, i.e. A/B-stacked or A/C-stacked. Empirical stacking rules, which successfully predict for DNA 3HS2 A/B-stacking preference from sequence, have been extended to A/C-stacked conformations. Three novel DNA 3HS2 sequences were designed to test the validity of these extended stacking rules and their conformational behavior was studied by solution NMR. All three show the predicted A/C-stacking preference even in the absence of multivalent cations. The stacking preference for both classes of DNA 3HS2 can thus be predicted from sequence. The high-resolution NMR solution structure for one of the stacked 3HS2 is also reported. It shows a well-defined local and global structure defined by an extensive set of classical NMR restraints and residual dipolar couplings. Analysis of its global conformation and that of other representatives of the 3H family, shows that the relative orientations of the stacked and non-stacked arms, are restricted to narrow regions of conformational space, which can be understood from geometric considerations. Together, these findings open up the possibility of full prediction of 3HS2 conformation (stacking and global fold) directly from sequence.
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Affiliation(s)
- Bin Wu
- Department of Physical Chemistry/Biophysical Chemistry, University of Nijmegen, Toernooiveld 1 6225 ED Nijmegen, The Netherlands
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24
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Abstract
The article reviews some recent developments in studying DNA sequence-dependent deformability, with emphasis on computer modeling. After a brief outline of available experimental techniques, we proceed to computational methods and focus on atomic-resolution molecular dynamics (MD) simulations. A sequence-dependent local (base-pair step) force field inferred from MD is compared with force fields obtained by other techniques. Various methods for establishing global (flexible-rod) DNA elastic constants are reviewed, including an approach based on atomic resolution MD. The problem of defining the global deformation variables, as well as the question of anisotropy and nonlocal effects, are discussed. As an example, both local and global deformability calculations from atomic-resolution MD of EcoRI dodecamer are presented.
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Affiliation(s)
- Filip Lankas
- German Cancer Research Centre (DKFZ), Im Neuenheimer Feld 580, 69120 Heidelberg, Germany.
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25
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Lu XJ, Olson WK. 3DNA: a software package for the analysis, rebuilding and visualization of three-dimensional nucleic acid structures. Nucleic Acids Res 2003; 31:5108-21. [PMID: 12930962 PMCID: PMC212791 DOI: 10.1093/nar/gkg680] [Citation(s) in RCA: 1268] [Impact Index Per Article: 60.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a comprehensive software package, 3DNA, for the analysis, reconstruction and visualization of three-dimensional nucleic acid structures. Starting from a coordinate file in Protein Data Bank (PDB) format, 3DNA can handle antiparallel and parallel double helices, single-stranded structures, triplexes, quadruplexes and other complex tertiary folding motifs found in both DNA and RNA structures. The analysis routines identify and categorize all base interactions and classify the double helical character of appropriate base pair steps. The program makes use of a recently recommended reference frame for the description of nucleic acid base pair geometry and a rigorous matrix-based scheme to calculate local conformational parameters and rebuild the structure from these parameters. The rebuilding routines produce rectangular block representations of nucleic acids as well as full atomic models with the sugar-phosphate backbone and publication quality 'standardized' base stacking diagrams. Utilities are provided to locate the base pairs and helical regions in a structure and to reorient structures for effective visualization. Regular helical models based on X-ray diffraction measurements of various repeating sequences can also be generated within the program.
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Affiliation(s)
- Xiang-Jun Lu
- Department of Chemistry and Chemical Biology, Wright-Rieman Laboratories, Rutgers-The State University of New Jersey, 610 Taylor Road, Piscataway, NJ 08854-8087, USA
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26
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Abstract
Popular programs for characterizing DNA structure include Curves 5.1 (Lavery, R. and Sklenar, H., J. Biomol. Struct. Dyn. 6, 63-91, 1988; Lavery, R. and Sklenar, H., J. Biomol. Struct. Dyn. 6, 655-67, 1989) and Freehelix98 (Dickerson, R. E., Nucleic Acids Res. 26, 1906-1926, 1998), along with the more recent 3DNA (X. J. Lu, Z. Shakked and W. K. Olson., J. Mol. Biol. 300, 819-840 (2000). Given input of structural coordinates, all of these programs return values of the local helical parameters, such as roll, tilt, twist, etc. The first two programs also provide characterization of global curvature. Madbend (Strahs, D. and Schlick, T., J. Mol. Biol. 301, 643-663, 2000), a program that computes global curvature from local roll, tilt, and twist parameters, can be applied to the output of all three structural programs. We have compared the curvature predicted by the three programs with and without the use of Madbend. Global bend magnitudes and directions as well as values of helical kinks were calculated for four high-resolution DNA structures and four model DNA helices. Global curvature determined by Curves 5.1 without Madbend was found to differ from values obtained using Freehelix98 with or without Madbend or 3DNA and Curves 5.1 with Madbend. Using model helices, this difference was attributed the fact that Curves 5.1 is the only program sensitive to changes in axial displacement, such as shift and slide. Madbend produced robust values of bend magnitude and direction, and displayed little sensitivity to axis displacement or the source of local helical parameters. Madbend also appears to be the method of choice for bending comparisons of high-resolution structures with results from cyclization kinetics, a method that measures DNA curvature as a vectorial sum of local roll and tilt angles.
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Affiliation(s)
- A Barbic
- Department of Chemistry, Yale University New Haven, CT 06511 USA.
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27
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28
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Olson WK, Bansal M, Burley SK, Dickerson RE, Gerstein M, Harvey SC, Heinemann U, Lu XJ, Neidle S, Shakked Z, Sklenar H, Suzuki M, Tung CS, Westhof E, Wolberger C, Berman HM. A standard reference frame for the description of nucleic acid base-pair geometry. J Mol Biol 2001; 313:229-37. [PMID: 11601858 DOI: 10.1006/jmbi.2001.4987] [Citation(s) in RCA: 446] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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29
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Affiliation(s)
- J O Trent
- James Graham Brown Cancer Center, Department of Medicine, University of Louisville, Louisville, Kentucky 40202, USA
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30
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Qian X, Strahs D, Schlick T. Dynamic simulations of 13 TATA variants refine kinetic hypotheses of sequence/activity relationships 1 1Edited by B. Honig. J Mol Biol 2001; 308:681-703. [PMID: 11350169 DOI: 10.1006/jmbi.2001.4617] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The fundamental relationship between DNA sequence/deformability and biological function has attracted numerous experimental and theoretical studies. A classic prototype system used for such studies in eukaryotes is the complex between the TATA element transcriptional regulator and the TATA-box binding protein (TBP). The recent crystallographic study by Burley and co-workers demonstrated the remarkable structural similarity contrasted to different transcriptional activity of 11 TBP/DNA complexes in which the DNAs differed by single base-pairs. By simulating these TATA variants and two other single base-pair variants that were not crystallizable, we uncover sequence-dependent structural, energetic, and flexibility properties that tailor TATA elements to TBP interactions, complementing many previous studies by refining kinetic hypotheses on sequence/activity correlations. The factors that combine to produce favorable elements for TBP activity include overall flexibility; minor groove widening, as well as roll, rise, and shift increases at the ends of the TATA element; untwisting within the TATA element accompanied by large roll at the TATA element ends; and relatively low maximal water densities around the DNA. These features accompany the severe deformation induced by the minor-groove binding protein, which kinks the TATA element at the ends and displaces local water molecules to form stabilizing hydrophobic contacts. Interestingly, the preferred bending direction itself is not a significant predictor of activity disposition, although certain variants (such as wild-type AdMLP, 5'-TATA4G-3', and inactive A29, 5'-TA6G-3') exhibit large preferred bends in directions consistent with their activity or inactivity (major groove and minor groove bends, respectively). These structural, flexibility, and hydration preferences, identified here and connected to a new crystallographic study of a larger group of DNA variants than reported to date, highlight the profound influence of single base-pair DNA variations on DNA motion. Our refined kinetic hypothesis suggests the functional implications of these motions in a kinetic model of TATA/TBP recognition, inviting further theoretical and experimental research.
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Affiliation(s)
- X Qian
- Department of Chemistry and Courant Institute of Mathematical Sciences, New York University and the Howard Hughes Medical Institute, 251 Mercer Street, New York, NY 10012, USA
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31
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Abstract
Harmonic elastic constants of 3-11 bp duplex DNA fragments were evaluated using four 5 ns unrestrained molecular dynamics simulation trajectories of 17 bp duplexes with explicit inclusion of solvent and counterions. All simulations were carried out with the Cornell et al. force-field and particle mesh Ewald method for long-range electrostatic interactions. The elastic constants including anisotropic bending and all coupling terms were derived by analyzing the correlations of fluctuations of structural properties along the trajectories. The following sequences have been considered: homopolymer d(ApA)(n) and d(GpG)(n), and alternating d(GPC)(n) and d(APT)(n). The calculated values of elastic constants are in very good overall agreement with experimental values for random sequences. The atomic-resolution molecular dynamics approach, however, reveals a pronounced sequence-dependence of the stretching and torsional rigidity of DNA, while sequence-dependence of the bending rigidity is smaller for the sequences considered. The earlier predicted twist-bend coupling emerged as the most important cross-term for fragments shorter than one helical turn. The calculated hydrodynamic relaxation times suggest that damping of bending motions may play a role in molecular dynamics simulations of long DNA fragments. A comparison of elasticity calculations using global and local helicoidal analyses is reported. The calculations reveal the importance of the fragment length definition. The present work shows that large-scale molecular dynamics simulations represent a unique source of data to study various aspects of DNA elasticity including its sequence-dependence.
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Affiliation(s)
- F Lankas
- J.Heyrovský Institute of Physical Chemistry, Dolejskova 3, Praha 8, 18200, Czech Republic.
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32
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Jin E, Katritch V, Olson WK, Kharatisvili M, Abagyan R, Pilch DS. Aminoglycoside binding in the major groove of duplex RNA: the thermodynamic and electrostatic forces that govern recognition. J Mol Biol 2000; 298:95-110. [PMID: 10756107 DOI: 10.1006/jmbi.2000.3639] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We use a combination of spectroscopic, calorimetric, viscometric and computer modeling techniques to characterize the binding of the aminoglycoside antibiotic, tobramycin, to the polymeric RNA duplex, poly(rI).poly(rC), which exhibits the characteristic A-type conformation that is conserved among natural and synthetic double-helical RNA sequences. Our results reveal the following significant features: (i) CD-detected binding of tobramycin to poly(rI).poly(rC) reveals an apparent site size of four base-pairs per bound drug molecule; (ii) tobramycin binding enhances the thermal stability of the host poly(rI).poly(rC) duplex, the extent of which decreases upon increasing in Na(+) concentration and/or pH conditions; (iii) the enthalpy of tobramycin- poly(rI).poly(rC) complexation increases with increasing pH conditions, an observation consistent with binding-induced protonation of one or more drug amino groups; (iv) the affinity of tobramycin for poly(rI).poly(rC) is sensitive to both pH and Na(+) concentration, with increases in pH and/or Na(+) concentration resulting in a concomitant reduction in binding affinity. The salt dependence of the tobramycin binding affinity reveals that the drug binds to the host RNA duplex as trication. (v) The thermodynamic driving force for tobramycin- poly(rI).poly(rC) complexation depends on pH conditions. Specifically, at pH< or =6.0, tobramycin binding is entropy driven, but is enthalpy driven at pH > 6.0. (vi) Viscometric data reveal non-intercalative binding properties when tobramycin complexes with poly(rI).poly(rC), consistent with a major groove-directed mode of binding. These data also are consistent with a binding-induced reduction in the apparent molecular length of the host RNA duplex. (vii) Computer modeling studies reveal a tobramycin-poly(rI). poly(rC) complex in which the drug fits snugly at the base of the RNA major groove and is stabilized, at least in part, by an array of hydrogen bonding interactions with both base and backbone atoms of the host RNA. These studies also demonstrate an inability of tobramycin to form a stable low-energy complex with the minor groove of the poly(rI).poly(rC) duplex. In the aggregate, our results suggest that tobramycin-RNA recognition is dictated and controlled by a broad range of factors that include electrostatic interactions, hydrogen bonding interactions, drug protonation reactions, and binding-induced alterations in the structure of the host RNA. These modulatory effects on tobramycin-RNA complexation are discussed in terms of their potential importance for the selective recognition of specific RNA structural motifs, such as asymmetric internal loops or hairpin loop-stem junctions, by aminoglycoside antibiotics and their derivatives.
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Affiliation(s)
- E Jin
- Department of Pharmacology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
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33
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Abstract
Growing interest in understanding the relationship between the global folding of nucleic acids and the sequence-dependent structure of individual base-pair steps has stimulated the development of new mathematical methods to define the geometry of the constituent base-pairs. Several approaches, designed to meet guidelines set by the nucleic acid community, permit rigorous comparative analyses of different three-dimensional structures, as well as allow for reconstruction of chain molecules at the base-pair level. The different computer programs, however, yield inconsistent descriptions of chain conformation. Here we report our own implementation of seven algorithms used to determine base-pair and dimer step parameters. Aside from reproducing the results of individual programs, we uncover the reasons why the different algorithms come to conflicting structural interpretations. The choice of mathematics has only a limited effect on the computed parameters, even in highly deformed duplexes. The results are much more sensitive to the choice of reference frame. The disparate schemes yield very similar conformational descriptions if the calculations are based on a common reference frame. The current positioning of reference frames at the inner and outer edges of complementary bases exaggerates the rise at distorted dimer steps, and points to the need for a carefully defined conformational standard.
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Affiliation(s)
- X J Lu
- Department of Chemistry, Rutgers, the State University of New Jersey, Wright-Rieman Laboratories, 610 Taylor Road, Piscataway, NJ, 08854-8087, USA
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