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Williams AM, Jolley EA, Santiago-Martínez MG, Chan CX, Gutell RR, Ferry JG, Bevilacqua PC. In vivo structure probing of RNA in Archaea: novel insights into the ribosome structure of Methanosarcina acetivorans. RNA (NEW YORK, N.Y.) 2023; 29:1610-1620. [PMID: 37491319 PMCID: PMC10578495 DOI: 10.1261/rna.079687.123] [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: 04/14/2023] [Accepted: 06/24/2023] [Indexed: 07/27/2023]
Abstract
Structure probing combined with next-generation sequencing (NGS) has provided novel insights into RNA structure-function relationships. To date, such studies have focused largely on bacteria and eukaryotes, with little attention given to the third domain of life, archaea. Furthermore, functional RNAs have not been extensively studied in archaea, leaving open questions about RNA structure and function within this domain of life. With archaeal species being diverse and having many similarities to both bacteria and eukaryotes, the archaea domain has the potential to be an evolutionary bridge. In this study, we introduce a method for probing RNA structure in vivo in the archaea domain of life. We investigated the structure of ribosomal RNA (rRNA) from Methanosarcina acetivorans, a well-studied anaerobic archaeal species, grown with either methanol or acetate. After probing the RNA in vivo with dimethyl sulfate (DMS), Structure-seq2 libraries were generated, sequenced, and analyzed. We mapped the reactivity of DMS onto the secondary structure of the ribosome, which we determined independently with comparative analysis, and confirmed the accuracy of DMS probing in M. acetivorans Accessibility of the rRNA to DMS in the two carbon sources was found to be quite similar, although some differences were found. Overall, this study establishes the Structure-seq2 pipeline in the archaea domain of life and informs about ribosomal structure within M. acetivorans.
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Affiliation(s)
- Allison M Williams
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Elizabeth A Jolley
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | | | - Cheong Xin Chan
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane QLD 4072, Australia
| | - Robin R Gutell
- Department of Integrative Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - James G Ferry
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Philip C Bevilacqua
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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2
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Lin HL, Mohamed Shukri FN, Yih ES, Sha GH, Jing GS, Jin GW, Hoong CW, Ying CQ, Panda BP, Candasamy M, Bhattamisra SK. Newer therapeutic approaches towards the management of diabetes mellitus: an update. Panminerva Med 2023; 65:362-375. [PMID: 31663302 DOI: 10.23736/s0031-0808.19.03655-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Diabetes mellitus is a chronic metabolic condition characterized by an elevation of blood glucose levels, resulting from defects in insulin secretion, insulin action, or both. The prevalence of the disease has been rapidly rising all over the globe at an alarming rate. Despite advances in the management of diabetes mellitus, it remains a growing epidemic that has become a significant public health burden due to its high healthcare costs and its complications. There is no cure has yet been found for the disease, however, treatment modalities include insulin and antidiabetic agents along with lifestyle modifications are still the mainstay of therapy for diabetes mellitus. The treatment spectrum for the management of diabetes mellitus has rapidly developed in recent years, with new class of therapeutics and expanded indications. This article focused on the emerging therapeutic approaches other than the conventional pharmacological therapies, which include stem cell therapy, gene therapy, siRNA, nanotechnology and theranostics.
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Affiliation(s)
- Heng L Lin
- School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia
| | | | - Eric S Yih
- School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia
| | - Grace H Sha
- School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia
| | - Grace S Jing
- School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia
| | - Gan W Jin
- School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia
| | - Chow W Hoong
- School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia
| | - Choong Q Ying
- School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia
| | - Bibhu P Panda
- Department of Pharmaceutical Technology, School of Pharmacy, Taylor's University, Lakeside Campus, Subang Jaya, Selangor, Malaysia
| | - Mayuren Candasamy
- Department of Life Sciences, School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia
| | - Subrat K Bhattamisra
- Department of Life Sciences, School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia -
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Chen K, Zhu X, Wang J, Hao L, Liu Z, Liu Y. ncDENSE: a novel computational method based on a deep learning framework for non-coding RNAs family prediction. BMC Bioinformatics 2023; 24:68. [PMID: 36849908 PMCID: PMC9972773 DOI: 10.1186/s12859-023-05191-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 02/16/2023] [Indexed: 03/01/2023] Open
Abstract
BACKGROUND Although research on non-coding RNAs (ncRNAs) is a hot topic in life sciences, the functions of numerous ncRNAs remain unclear. In recent years, researchers have found that ncRNAs of the same family have similar functions, therefore, it is important to accurately predict ncRNAs families to identify their functions. There are several methods available to solve the prediction problem of ncRNAs family, whose main ideas can be divided into two categories, including prediction based on the secondary structure features of ncRNAs, and prediction according to sequence features of ncRNAs. The first type of prediction method requires a complicated process and has a low accuracy in obtaining the secondary structure of ncRNAs, while the second type of method has a simple prediction process and a high accuracy, but there is still room for improvement. The existing methods for ncRNAs family prediction are associated with problems such as complicated prediction processes and low accuracy, in this regard, it is necessary to propose a new method to predict the ncRNAs family more perfectly. RESULTS A deep learning model-based method, ncDENSE, was proposed in this study, which predicted ncRNAs families by extracting ncRNAs sequence features. The bases in ncRNAs sequences were encoded by one-hot coding and later fed into an ensemble deep learning model, which contained the dynamic bi-directional gated recurrent unit (Bi-GRU), the dense convolutional network (DenseNet), and the Attention Mechanism (AM). To be specific, dynamic Bi-GRU was used to extract contextual feature information and capture long-term dependencies of ncRNAs sequences. AM was employed to assign different weights to features extracted by Bi-GRU and focused the attention on information with greater weights. Whereas DenseNet was adopted to extract local feature information of ncRNAs sequences and classify them by the full connection layer. According to our results, the ncDENSE method improved the Accuracy, Sensitivity, Precision, F-score, and MCC by 2.08[Formula: see text], 2.33[Formula: see text], 2.14[Formula: see text], 2.16[Formula: see text], and 2.39[Formula: see text], respectively, compared with the suboptimal method. CONCLUSIONS Overall, the ncDENSE method proposed in this paper extracts sequence features of ncRNAs by dynamic Bi-GRU and DenseNet and improves the accuracy in predicting ncRNAs family and other data.
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Affiliation(s)
- Kai Chen
- grid.64924.3d0000 0004 1760 5735College of Software, Jilin University, Changchun, 130012 China ,grid.64924.3d0000 0004 1760 5735Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education, Jilin University, Changchun, 130012 China
| | - Xiaodong Zhu
- grid.64924.3d0000 0004 1760 5735College of Software, Jilin University, Changchun, 130012 China ,grid.64924.3d0000 0004 1760 5735Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education, Jilin University, Changchun, 130012 China ,grid.64924.3d0000 0004 1760 5735College of Computer Science and Technology, Jilin University, Changchun, 130012 China
| | - Jiahao Wang
- grid.64924.3d0000 0004 1760 5735College of Software, Jilin University, Changchun, 130012 China ,grid.64924.3d0000 0004 1760 5735Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education, Jilin University, Changchun, 130012 China
| | - Lei Hao
- grid.64924.3d0000 0004 1760 5735College of Software, Jilin University, Changchun, 130012 China ,grid.64924.3d0000 0004 1760 5735Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education, Jilin University, Changchun, 130012 China
| | - Zhen Liu
- grid.64924.3d0000 0004 1760 5735College of Computer Science and Technology, Jilin University, Changchun, 130012 China ,grid.444367.60000 0000 9853 5396Graduate School of Engineering, Nagasaki Institute of Applied Science, 536 Aba-machi, Nagasaki 851-0193 Japan
| | - Yuanning Liu
- College of Software, Jilin University, Changchun, 130012, China. .,Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education, Jilin University, Changchun, 130012, China. .,College of Computer Science and Technology, Jilin University, Changchun, 130012, China.
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4
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Chawla M, Kalra K, Cao Z, Cavallo L, Oliva R. Occurrence and stability of anion-π interactions between phosphate and nucleobases in functional RNA molecules. Nucleic Acids Res 2022; 50:11455-11469. [PMID: 36416268 PMCID: PMC9723503 DOI: 10.1093/nar/gkac1081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 10/19/2022] [Accepted: 10/26/2022] [Indexed: 11/24/2022] Open
Abstract
We present a systematic structural and energetic characterization of phosphate(OP)-nucleobase anion…π stacking interactions in RNAs. We observed OP-nucleobase stacking contacts in a variety of structural motifs other than regular helices and spanning broadly diverse sequence distances. Apart from the stacking between a phosphate and a guanine or a uracil two-residue upstream in specific U-turns, such interactions in RNA have been scarcely characterized to date. Our QM calculations showed an energy minimum at a distance between the OP atom and the nucleobase plane centroid slightly below 3 Å for all the nucleobases. By sliding the OP atom over the nucleobase plane we localized the optimal mutual positioning of the stacked moieties, corresponding to an energy minimum below -6 kcal•mol-1, for all the nucleobases, consistently with the projections of the OP atoms over the different π-rings we observed in experimental occurrences. We also found that the strength of the interaction clearly correlates with its electrostatic component, pointing to it as the most relevant contribution. Finally, as OP-uracil and OP-guanine interactions represent together 86% of the instances we detected, we also proved their stability under dynamic conditions in model systems simulated by state-of-the art DFT-MD calculations.
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Affiliation(s)
- Mohit Chawla
- Correspondence may also be addressed to Mohit Chawla. ;
| | - Kanav Kalra
- Department of Research and Innovation, STEMskills Research and Education Lab Private Limited, Faridabad 121002, Haryana, India
| | - Zhen Cao
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Kaust Catalysis Center, Thuwal 23955-6900, Saudi Arabia
| | - Luigi Cavallo
- Correspondence may also be addressed to Luigi Cavallo. Tel: +966 02 8027566; Fax: +966 02 8021347;
| | - Romina Oliva
- To whom correspondence should be addressed. Tel: +39 081 5476541; Fax: +39 081 5476514;
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5
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Felder S, Sagné C, Benedetti E, Micouin L. Small-Molecule 3D Ligand for RNA Recognition: Tuning Selectivity through Scaffold Hopping. ACS Chem Biol 2022; 17:3069-3076. [PMID: 36314850 DOI: 10.1021/acschembio.2c00171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Targeting RNAs with small molecules is considered the next frontier for drug discovery. In this context, the development of compounds capable of binding RNA structural motifs of low complexity with high affinity and selectivity would greatly expand the number of targets of potential therapeutic value. In this study, we demonstrate that tuning the three-dimensional shape of promiscuous nucleic acid binders is a valuable strategy for the design of new selective RNA ligands. Indeed, starting from a known cyanine, the simple replacement of a phenyl ring with a [2.2]paracyclophane moiety led to a new compound able to discriminate between nucleic acids showing different structural characteristics with a marked affinity and selectivity for an octahairpin loop RNA sequence. This shape modification also affected the in cellulo behavior of the cyanine. These results suggest that scaffold hopping is a valuable strategy to improve the selectivity of RNA/small-molecule interactions and highlight the need to explore a new chemical space for the design of selective RNA ligands.
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Affiliation(s)
- Simon Felder
- Université Paris Cité, CNRS, Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, F-75006 Paris, France
| | - Corinne Sagné
- Université Paris Cité, CNRS, Saints-Pères Paris Institute for the Neurosciences, F-75006 Paris, France
| | - Erica Benedetti
- Université Paris Cité, CNRS, Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, F-75006 Paris, France
| | - Laurent Micouin
- Université Paris Cité, CNRS, Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, F-75006 Paris, France
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6
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Bugnon LA, Edera AA, Prochetto S, Gerard M, Raad J, Fenoy E, Rubiolo M, Chorostecki U, Gabaldón T, Ariel F, Di Persia LE, Milone DH, Stegmayer G. Secondary structure prediction of long noncoding RNA: review and experimental comparison of existing approaches. Brief Bioinform 2022; 23:6606044. [PMID: 35692094 DOI: 10.1093/bib/bbac205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/02/2022] [Accepted: 05/04/2022] [Indexed: 11/12/2022] Open
Abstract
MOTIVATION In contrast to messenger RNAs, the function of the wide range of existing long noncoding RNAs (lncRNAs) largely depends on their structure, which determines interactions with partner molecules. Thus, the determination or prediction of the secondary structure of lncRNAs is critical to uncover their function. Classical approaches for predicting RNA secondary structure have been based on dynamic programming and thermodynamic calculations. In the last 4 years, a growing number of machine learning (ML)-based models, including deep learning (DL), have achieved breakthrough performance in structure prediction of biomolecules such as proteins and have outperformed classical methods in short transcripts folding. Nevertheless, the accurate prediction for lncRNA still remains far from being effectively solved. Notably, the myriad of new proposals has not been systematically and experimentally evaluated. RESULTS In this work, we compare the performance of the classical methods as well as the most recently proposed approaches for secondary structure prediction of RNA sequences using a unified and consistent experimental setup. We use the publicly available structural profiles for 3023 yeast RNA sequences, and a novel benchmark of well-characterized lncRNA structures from different species. Moreover, we propose a novel metric to assess the predictive performance of methods, exclusively based on the chemical probing data commonly used for profiling RNA structures, avoiding any potential bias incorporated by computational predictions when using dot-bracket references. Our results provide a comprehensive comparative assessment of existing methodologies, and a novel and public benchmark resource to aid in the development and comparison of future approaches. AVAILABILITY Full source code and benchmark datasets are available at: https://github.com/sinc-lab/lncRNA-folding. CONTACT lbugnon@sinc.unl.edu.ar.
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Affiliation(s)
- L A Bugnon
- Research Institute for Signals, Systems and Computational Intelligence sinc(i) (CONICET-UNL), Ciudad Universitaria, Santa Fe, Argentina
| | - A A Edera
- Research Institute for Signals, Systems and Computational Intelligence sinc(i) (CONICET-UNL), Ciudad Universitaria, Santa Fe, Argentina
| | - S Prochetto
- Research Institute for Signals, Systems and Computational Intelligence sinc(i) (CONICET-UNL), Ciudad Universitaria, Santa Fe, Argentina.,IAL, CONICET, Ciudad Universitaria UNL, (3000) Santa Fe, Argentina
| | - M Gerard
- Research Institute for Signals, Systems and Computational Intelligence sinc(i) (CONICET-UNL), Ciudad Universitaria, Santa Fe, Argentina
| | - J Raad
- Research Institute for Signals, Systems and Computational Intelligence sinc(i) (CONICET-UNL), Ciudad Universitaria, Santa Fe, Argentina
| | - E Fenoy
- Research Institute for Signals, Systems and Computational Intelligence sinc(i) (CONICET-UNL), Ciudad Universitaria, Santa Fe, Argentina
| | - M Rubiolo
- Research Institute for Signals, Systems and Computational Intelligence sinc(i) (CONICET-UNL), Ciudad Universitaria, Santa Fe, Argentina
| | - U Chorostecki
- Barcelona Supercomputing Center (BSC-CNS), Institute of Research in Biomedicine (IRB), Spain
| | - T Gabaldón
- Barcelona Supercomputing Center (BSC-CNS), Institute of Research in Biomedicine (IRB), Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.,Centro de Investigación Biomédica En Red de Enfermedades Infecciosas (CIBERINFEC), Barcelona, Spain
| | - F Ariel
- IAL, CONICET, Ciudad Universitaria UNL, (3000) Santa Fe, Argentina
| | - L E Di Persia
- Research Institute for Signals, Systems and Computational Intelligence sinc(i) (CONICET-UNL), Ciudad Universitaria, Santa Fe, Argentina
| | - D H Milone
- Research Institute for Signals, Systems and Computational Intelligence sinc(i) (CONICET-UNL), Ciudad Universitaria, Santa Fe, Argentina
| | - G Stegmayer
- Research Institute for Signals, Systems and Computational Intelligence sinc(i) (CONICET-UNL), Ciudad Universitaria, Santa Fe, Argentina
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7
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Grillone K, Riillo C, Scionti F, Rocca R, Tradigo G, Guzzi PH, Alcaro S, Di Martino MT, Tagliaferri P, Tassone P. Non-coding RNAs in cancer: platforms and strategies for investigating the genomic "dark matter". J Exp Clin Cancer Res 2020; 39:117. [PMID: 32563270 PMCID: PMC7305591 DOI: 10.1186/s13046-020-01622-x] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/11/2020] [Indexed: 12/18/2022] Open
Abstract
The discovery of the role of non-coding RNAs (ncRNAs) in the onset and progression of malignancies is a promising frontier of cancer genetics. It is clear that ncRNAs are candidates for therapeutic intervention, since they may act as biomarkers or key regulators of cancer gene network. Recently, profiling and sequencing of ncRNAs disclosed deep deregulation in human cancers mostly due to aberrant mechanisms of ncRNAs biogenesis, such as amplification, deletion, abnormal epigenetic or transcriptional regulation. Although dysregulated ncRNAs may promote hallmarks of cancer as oncogenes or antagonize them as tumor suppressors, the mechanisms behind these events remain to be clarified. The development of new bioinformatic tools as well as novel molecular technologies is a challenging opportunity to disclose the role of the "dark matter" of the genome. In this review, we focus on currently available platforms, computational analyses and experimental strategies to investigate ncRNAs in cancer. We highlight the differences among experimental approaches aimed to dissect miRNAs and lncRNAs, which are the most studied ncRNAs. These two classes indeed need different investigation taking into account their intrinsic characteristics, such as length, structures and also the interacting molecules. Finally, we discuss the relevance of ncRNAs in clinical practice by considering promises and challenges behind the bench to bedside translation.
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Affiliation(s)
- Katia Grillone
- Laboratory of Translational Medical Oncology, Department of Experimental and Clinical Medicine, Magna Graecia University, Salvatore Venuta University Campus, 88100 Catanzaro, Italy
| | - Caterina Riillo
- Laboratory of Translational Medical Oncology, Department of Experimental and Clinical Medicine, Magna Graecia University, Salvatore Venuta University Campus, 88100 Catanzaro, Italy
- Medical and Translational Oncology Units, AOU Mater Domini, 88100 Catanzaro, Italy
| | - Francesca Scionti
- Laboratory of Translational Medical Oncology, Department of Experimental and Clinical Medicine, Magna Graecia University, Salvatore Venuta University Campus, 88100 Catanzaro, Italy
| | - Roberta Rocca
- Laboratory of Translational Medical Oncology, Department of Experimental and Clinical Medicine, Magna Graecia University, Salvatore Venuta University Campus, 88100 Catanzaro, Italy
- Net4science srl, Magna Graecia University, Salvatore Venuta University Campus, 88100 Catanzaro, Italy
| | - Giuseppe Tradigo
- Laboratory of Bioinformatics, Department of Medical and Surgical Sciences, Magna Graecia University, Salvatore Venuta University Campus, 88100 Catanzaro, Italy
| | - Pietro Hiram Guzzi
- Laboratory of Bioinformatics, Department of Medical and Surgical Sciences, Magna Graecia University, Salvatore Venuta University Campus, 88100 Catanzaro, Italy
| | - Stefano Alcaro
- Net4science srl, Magna Graecia University, Salvatore Venuta University Campus, 88100 Catanzaro, Italy
- Department of Health Sciences, Magna Græcia University, Salvatore Venuta University Campus, 88100 Catanzaro, Italy
| | - Maria Teresa Di Martino
- Laboratory of Translational Medical Oncology, Department of Experimental and Clinical Medicine, Magna Graecia University, Salvatore Venuta University Campus, 88100 Catanzaro, Italy
- Medical and Translational Oncology Units, AOU Mater Domini, 88100 Catanzaro, Italy
| | - Pierosandro Tagliaferri
- Laboratory of Translational Medical Oncology, Department of Experimental and Clinical Medicine, Magna Graecia University, Salvatore Venuta University Campus, 88100 Catanzaro, Italy
- Medical and Translational Oncology Units, AOU Mater Domini, 88100 Catanzaro, Italy
| | - Pierfrancesco Tassone
- Laboratory of Translational Medical Oncology, Department of Experimental and Clinical Medicine, Magna Graecia University, Salvatore Venuta University Campus, 88100 Catanzaro, Italy
- Medical and Translational Oncology Units, AOU Mater Domini, 88100 Catanzaro, Italy
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8
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Voronova AN, Chelomina GN. The SSU rRNA secondary structures of the Plagiorchiida species (Digenea), its applications in systematics and evolutionary inferences. INFECTION GENETICS AND EVOLUTION 2019; 78:104042. [PMID: 31770596 DOI: 10.1016/j.meegid.2019.104042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 08/05/2019] [Accepted: 09/16/2019] [Indexed: 10/25/2022]
Abstract
The small subunit ribosomal RNA (SSU rRNA) is widely used phylogenetic marker in broad groups of organisms and its secondary structure increasingly attracts the attention of researchers as supplementary tool in sequence alignment and advanced phylogenetic studies. Its comparative analysis provides a great contribution to evolutionary biology, allowing find out how the SSU rRNA secondary structure originated, developed and evolved. Herein, we provide the first data on the putative SSU rRNA secondary structures of the Plagiorchiida species. The structures were found to be quite conserved across broad range of species studied, well compatible with those of others eukaryotic SSU rRNA and possessed some peculiarities: cross-shaped structure of the ES6b, additional shortened ES6c2 helix, and elongated ES6a helix and h39 + ES9 region. The secondary structures of variable regions ES3 and ES7 appeared to be tissue-specific while ES6 and ES9 were specific at a family level allowing considering them as promising markers for digenean systematics. Their uniqueness more depends on the length than on the nucleotide diversity of primary sequences which evolutionary rates well differ. The findings have important implications for understanding rRNA evolution, developing molecular taxonomy and systematics of Plagiorchiida as well as for constructing new anthelmintic drugs.
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Affiliation(s)
- A N Voronova
- Federal Scientific Center of the East Asia Terrestrial Biodiversity FEB RAS, 7 Russia, 100-letiya Street, 159, Vladivostok 690022, Russia
| | - G N Chelomina
- Federal Scientific Center of the East Asia Terrestrial Biodiversity FEB RAS, 7 Russia, 100-letiya Street, 159, Vladivostok 690022, Russia.
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9
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Emamjomeh A, Zahiri J, Asadian M, Behmanesh M, Fakheri BA, Mahdevar G. Identification, Prediction and Data Analysis of Noncoding RNAs: A Review. Med Chem 2019; 15:216-230. [PMID: 30484409 DOI: 10.2174/1573406414666181015151610] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 06/03/2018] [Accepted: 09/30/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND Noncoding RNAs (ncRNAs) which play an important role in various cellular processes are important in medicine as well as in drug design strategies. Different studies have shown that ncRNAs are dis-regulated in cancer cells and play an important role in human tumorigenesis. Therefore, it is important to identify and predict such molecules by experimental and computational methods, respectively. However, to avoid expensive experimental methods, computational algorithms have been developed for accurately and fast prediction of ncRNAs. OBJECTIVE The aim of this review was to introduce the experimental and computational methods to identify and predict ncRNAs structure. Also, we explained the ncRNA's roles in cellular processes and drugs design, briefly. METHOD In this survey, we will introduce ncRNAs and their roles in biological and medicinal processes. Then, some important laboratory techniques will be studied to identify ncRNAs. Finally, the state-of-the-art models and algorithms will be introduced along with important tools and databases. RESULTS The results showed that the integration of experimental and computational approaches improves to identify ncRNAs. Moreover, the high accurate databases, algorithms and tools were compared to predict the ncRNAs. CONCLUSION ncRNAs prediction is an exciting research field, but there are different difficulties. It requires accurate and reliable algorithms and tools. Also, it should be mentioned that computational costs of such algorithm including running time and usage memory are very important. Finally, some suggestions were presented to improve computational methods of ncRNAs gene and structural prediction.
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Affiliation(s)
- Abbasali Emamjomeh
- Laboratory of Computational Biotechnology and Bioinformatics (CBB), Department of Plant Breeding and Biotechnology (PBB), University of Zabol, Zabol, Iran
| | - Javad Zahiri
- Bioinformatics and Computational Omics Lab (BioCOOL), Department of Biophysics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mehrdad Asadian
- Department of Plant Breeding and Biotechnology (PBB), Faculty of Agriculture, University of Zabol, Zabol, Iran
| | - Mehrdad Behmanesh
- Department of Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Barat A Fakheri
- Department of Plant Breeding and Biotechnology (PBB), Faculty of Agriculture, University of Zabol, Zabol, Iran
| | - Ghasem Mahdevar
- Department of Mathematics, Faculty of Sciences, University of Isfahan, Isfahan, Iran
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10
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Berger KD, Kennedy SD, Turner DH. Nuclear Magnetic Resonance Reveals That GU Base Pairs Flanking Internal Loops Can Adopt Diverse Structures. Biochemistry 2019; 58:1094-1108. [PMID: 30702283 DOI: 10.1021/acs.biochem.8b01027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
RNA thermodynamics play an important role in determining the two- and three-dimensional structures of RNA. Internal loops of the sequence 5'-GMNU/3'-UNMG are relatively unstable thermodynamically. Here, five duplexes with GU-flanked 2 × 2 nucleotide internal loops were structurally investigated to reveal determinants of their instability. The following internal loops were investigated: 5'-GCAU/3'-UACG, 5'-UUCG/3'-GCUU, 5'-GCUU/3'-UUCG, 5'-GUCU/3'-UCUG, and 5'-GCCU/3'-UCCG. Two-dimensional nuclear magnetic resonance spectra indicate the absence of GU wobble base pairing in 5'-GCUU/3'-UUCG, 5'-GUCU/3'-UCUG, and 5'-GCCU/3'-UCCG. The 5'-GCUU/3'-UUCG loop has an unusual conformation of the GU base pairs, in which U's O2 carbonyl forms a bifurcated hydrogen bond with G's amino and imino protons. The internal loop of 5'-GUCU/3'-UCUG displays a shifted configuration in which GC pairs flank a U-U pair and several U's are in fast exchange between positions inside and outside the helix. In contrast, 5'-GCAU/3'-UACG and 5'-UUCG/3'-GCUU both have the expected GU wobble base pairs flanking the internal loop. Evidently, GU base pairs flanking internal loops are more likely to display atypical structures relative to Watson-Crick base pairs flanking internal loops. This appears to be more likely when the G of the GU pair is 5' to the loop. Such unusual structures could serve as recognition elements for biological function and as benchmarks for structure prediction methods.
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Affiliation(s)
- Kyle D Berger
- Department of Biochemistry and Biophysics , University of Rochester School of Medicine and Dentistry , Rochester , New York 14642 , United States.,Center for RNA Biology , University of Rochester School of Medicine and Dentistry , Rochester , New York 14642 , United States
| | - Scott D Kennedy
- Department of Biochemistry and Biophysics , University of Rochester School of Medicine and Dentistry , Rochester , New York 14642 , United States.,Center for RNA Biology , University of Rochester School of Medicine and Dentistry , Rochester , New York 14642 , United States
| | - Douglas H Turner
- Center for RNA Biology , University of Rochester School of Medicine and Dentistry , Rochester , New York 14642 , United States.,Department of Chemistry , University of Rochester , Rochester , New York 14627 , United States
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11
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Abstract
Diabetes is a condition that is not completely treatable but life of a diabetic patient can be smoothed by preventing or delaying the associate conditions like diabetic retinopathy, nephropathy, impaired wound healing process, etc. Apart from conventional methods to regulate diabetic condition, new techniques using siRNA have been emerged to prevent the associated conditions. This paper focuses on how siRNA used as a tool to silence the expression of genes which plays critical role in pathogenesis of these conditions. A marked improvement in wound-healing process of diabetic patients has been observed with siRNA treatment by silencing of Keap1 gene. Glucagon plays critical role in glucose homoeostasis and increases blood glucose level during hypoglycaemia. Glucose homoeostasis is impaired in diabetic patient and suppressing the expression of glucagon secretion with siRNA is used to suppress the progress of diabetes. Similarly, silencing expression of several factors has demonstrated improvement of treatment of diabetic nephropathy, retinopathy and inflammation by the use of siRNA.
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Affiliation(s)
- Pravin Shende
- a Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management , SVKM'S NMIMS , Mumbai , India
| | - Chirag Patel
- a Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management , SVKM'S NMIMS , Mumbai , India
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12
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Amini SK. Relative Populations of Some Tautomeric Forms of 2'-Deoxyguanosine-5-Fluorouridine Mismatch. J Phys Chem B 2018; 122:4433-4444. [PMID: 29608855 DOI: 10.1021/acs.jpcb.8b00818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The importance of the 2'-deoxyguanosine-uridine mispair as the most occurring mismatch in transcriptional studies of RNAs from DNAs is multiplied when 5-halo-substituted uridine species cause a serious increase in the probability of its occurrence. Many studies relate this higher probability to the existence of possible tautomeric and ionic forms of its constituent bases. According to these statements, relative populations of mismatches between 5-fluorouridine and both keto and enol forms of 2'-deoxyguanosine are computed by using a conformational search. In order to have a complete scan of all of the highly probable conformers in a moderate computational time, an extensive conformational search methodology is employed here, which benefits from the advantages of both the molecular dynamics simulations and quantum mechanics calculations. The population of an enolic tautomer of normal wobble orientation is about 0.057% of that of its keto tautomer, whereas the population of an enolic tautomer of reverse wobble orientation is about 0.0054% of that of its keto tautomer. Totally, the reverse wobble orientation is about six times more populated than the normal wobble orientation. Calculated populations are in good agreement with experimental populations of closely related compounds. The reliability of the applied methodology is certified, in part, by a good agreement obtained between some experimental data and corresponding Boltzmann-weighted average data of most probable conformers such as NMR parameters. The validation of this methodology is certified with high accuracy by applying it on the substituted diuridine pairs, where experimental populations are available. Not only are the calculated populations and NMR parameters of this test in very good agreement with the experimental data, but also they are free of the ambiguities mentioned by experimentalists.
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Affiliation(s)
- Saeed K Amini
- Chemistry and Chemical Engineering Research Center of Iran , Tehran , Iran
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13
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Islam S, Ge P, Zhang S. CompAnnotate: a comparative approach to annotate base-pairing interactions in RNA 3D structures. Nucleic Acids Res 2017. [PMID: 28641399 PMCID: PMC5737500 DOI: 10.1093/nar/gkx538] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The analysis of RNA tertiary structure is hindered by the fact that not too many structural data are available and a significant amount of them are in low resolution. Due to the atomic coordinate errors posed by the limitations of low-resolution RNA three-dimensional structures, it becomes a critical challenge to extract key geometric characteristics of RNA, particularly, the interaction of bases. To address this issue, we have devised a comparative method, named CompAnnotate, that utilizes more precise structural information of high-resolution homologs to annotate the base-pairing interactions in the low-resolution structures, by aligning and making comparative geometric assessments. The benchmarking results show that our method can improve the annotations of the existing methods significantly. We have achieved different levels of improvements for various methods and datasets, including an example of significant sensitivity and precision enhancement from 28 to 57% and from 53 to 82%, respectively.
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Affiliation(s)
- Shahidul Islam
- Department of Computer Science, University of Central Florida, Orlando, FL 32816, USA
| | - Ping Ge
- Department of Computer Science, University of Central Florida, Orlando, FL 32816, USA
| | - Shaojie Zhang
- Department of Computer Science, University of Central Florida, Orlando, FL 32816, USA
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14
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Halder A, Roy R, Bhattacharyya D, Mitra A. How Does Mg 2+ Modulate the RNA Folding Mechanism: A Case Study of the G:C W:W Trans Basepair. Biophys J 2017; 113:277-289. [PMID: 28506525 DOI: 10.1016/j.bpj.2017.04.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/18/2017] [Accepted: 04/21/2017] [Indexed: 12/30/2022] Open
Abstract
Reverse Watson-Crick G:C basepairs (G:C W:W Trans) occur frequently in different functional RNAs. This is one of the few basepairs whose gas-phase-optimized isolated geometry is inconsistent with the corresponding experimental geometry. Several earlier studies indicate that through post-transcriptional modification, direct protonation, or coordination with Mg2+, accumulation of positive charge near N7 of guanine can stabilize the experimental geometry. Interestingly, recent studies reveal significant variation in the position of putatively bound Mg2+. This, in conjunction with recently raised doubts regarding some of the Mg2+ assignments near the imino nitrogen of guanine, is suggestive of the existence of multiple Mg2+ binding modes for this basepair. Our detailed investigation of Mg2+-bound G:C W:W Trans pairs occurring in high-resolution RNA crystal structures shows that they are found in 14 different contexts, eight of which display Mg2+ binding at the Hoogsteen edge of guanine. Further examination of occurrences in these eight contexts led to the characterization of three different Mg2+ binding modes: 1) direct binding via N7 coordination, 2) direct binding via O6 coordination, and 3) binding via hydrogen-bonding interaction with the first-shell water molecules. In the crystal structures, the latter two modes are associated with a buckled and propeller-twisted geometry of the basepair. Interestingly, respective optimized geometries of these different Mg2+ binding modes (optimized using six different DFT functionals) are consistent with their corresponding experimental geometries. Subsequent interaction energy calculations at the MP2 level, and decomposition of its components, suggest that for G:C W:W Trans , Mg2+ binding can fine tune the basepair geometries without compromising with their stability. Our results, therefore, underline the importance of the mode of binding of Mg2+ ions in shaping RNA structure, folding and function.
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Affiliation(s)
- Antarip Halder
- Center for Computational Natural Sciences and Bioinformatics (CCNSB), International Institute of Information Technology (IIIT-H), Gachibowli, Hyderabad, India
| | - Rohit Roy
- Center for Computational Natural Sciences and Bioinformatics (CCNSB), International Institute of Information Technology (IIIT-H), Gachibowli, Hyderabad, India
| | | | - Abhijit Mitra
- Center for Computational Natural Sciences and Bioinformatics (CCNSB), International Institute of Information Technology (IIIT-H), Gachibowli, Hyderabad, India.
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15
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Brovarets' OO, Hovorun DM. A novel conception for spontaneous transversions caused by homo-pyrimidine DNA mismatches: a QM/QTAIM highlight. Phys Chem Chem Phys 2016. [PMID: 26219928 DOI: 10.1039/c5cp03211c] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We have firstly shown that the T·T(w) and C·C(w) DNA mismatches with wobble (w) geometry stay in slow tautomeric equilibrium with short T·T*(WC) and C·C*(WC) Watson-Crick (WC) mispairs. These non-dissociative tautomeric rearrangements are controlled by the plane-symmetric, highly stable, highly polar and zwitterionic transition states. The obtained results allow us to understand in what way the T·T(w) and C·C(w) mismatches acquire enzymatically competent T·T*(WC) and C·C*(WC) conformations directly in the hydrophobic recognition pocket of a high-fidelity DNA-polymerase, thereby producing thermodynamically non-equilibrium spontaneous transversions. The simplest numerical estimation of the frequency ratio of the TT to CC spontaneous transversions satisfactorily agrees with experimental data.
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Affiliation(s)
- Ol'ha O Brovarets'
- Department of Molecular and Quantum Biophysics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 150 Akademika Zabolotnoho Str., 03680 Kyiv, Ukraine.
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16
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Brovarets' OO, Hovorun DM. How does the long G·G* Watson-Crick DNA base mispair comprising keto and enol tautomers of the guanine tautomerise? The results of a QM/QTAIM investigation. Phys Chem Chem Phys 2015; 16:15886-99. [PMID: 24964351 DOI: 10.1039/c4cp01241k] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The double proton transfer (DPT) in the long G·G* Watson-Crick base mispair (|C6N1(G*)N1C6(G)| = 36.4°; C1 symmetry), involving keto and enol tautomers of the guanine (G) nucleobase, along two intermolecular neighboring O6H···O6 (8.39) and N1···HN1 (6.14 kcal mol(-1)) H-bonds that were established to be slightly anti-cooperative, leads to its transformation into the G*·G base mispair through a single transition state (|C6N1N1C6| = 37.1°; C1), namely to the interconversion into itself. It was shown that the G·G* ↔ G*·G tautomerisation via the DPT is assisted by the third specific contact, that sequentially switches along the intrinsic reaction coordinate (IRC) in an original way: (G)N2H···N2(G*) H-bond (-25.13 to -10.37) → N2···N2 van der Waals contact (-10.37 to -9.23) → (G)N2···HN2(G*) H-bond (-9.23 to 0.79) → (G*)N2···HN2(G) H-bond (0.79 to 7.35 Bohr). The DPT tautomerisation was found to proceed through the asynchronous concerted mechanism by employing the QM/QTAIM approach and the methodology of the scans of the geometric, electron-topological, energetic, polar and NBO properties along the IRC. Nine key points, that can be considered as part of the tautomerisation repertoire, have been established and analyzed in detail. Furthermore, it was shown that the G·G* or G*·G base mispair is a thermodynamically and dynamically stable structure with a lifetime of 8.22 × 10(-10) s and all 6 low-frequency intermolecular vibrations are able to develop during this time span. Lastly, our results highlight the importance of the G·G* ↔ G*·G DPT tautomerisation, which can have implications for biological and chemical sensing applications.
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Affiliation(s)
- Ol'ha O Brovarets'
- Department of Molecular and Quantum Biophysics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 150 Akademika Zabolotnoho Str., 03680 Kyiv, Ukraine.
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17
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Petrov AS, Williams LD. The ancient heart of the ribosomal large subunit: a response to Caetano-Anolles. J Mol Evol 2015; 80:166-70. [PMID: 25877522 DOI: 10.1007/s00239-015-9678-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Accepted: 04/07/2015] [Indexed: 01/21/2023]
Abstract
Our recent Accretion Model of ribosomal evolution uses insertion fingerprints and a "trunk-branch" formalism to recapitulate the building up of common core rRNA of the Large Ribosomal Subunit. The Accretion Model is a conservative and natural extension of a method developed by Bokov and Steinberg (Nature 457:977-80, 2009), which confirms the correctness of lower resolution models by Fox and others. In each of these models, the LSU originates with the peptidyl transferase center (PTC), consistent with expectations that the ribosome is the source of defined-sequence functional proteins. In an adjacent note, Caetano-Anolles (J Mol Evol 80:162-165, 2015) disparages the Accretion Model, because it controverts the 'Growth Inferred by Genothermal Ordering' (GIGO) model. GIGO analyzes secondary structures, assigns the origin of the ribosome to a region outside of the PTC, and assumes or deduces that (i) large protein enzymes of defined amino acid sequence predate ribosomal synthesis of proteins, (ii) proteins directly replicate by non-ribosomal mechanisms, (iii) rRNA unfailingly increases in thermodynamic stability over time, and (iv) the Woese and Fox canonical tree of life is mis-rooted. Much of the specific GIGO critique of the Accretion Model is based on confusion about the three-dimensional nature of RNA and trunk-branch polymorphism; the Accretion Model incorporates several types of trunk-branch relationships.
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Affiliation(s)
- Anton S Petrov
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA
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18
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Sochacka E, Szczepanowski RH, Cypryk M, Sobczak M, Janicka M, Kraszewska K, Bartos P, Chwialkowska A, Nawrot B. 2-Thiouracil deprived of thiocarbonyl function preferentially base pairs with guanine rather than adenine in RNA and DNA duplexes. Nucleic Acids Res 2015; 43:2499-512. [PMID: 25690900 PMCID: PMC4357714 DOI: 10.1093/nar/gkv109] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 01/30/2015] [Accepted: 02/02/2015] [Indexed: 12/12/2022] Open
Abstract
2-Thiouracil-containing nucleosides are essential modified units of natural and synthetic nucleic acids. In particular, the 5-substituted-2-thiouridines (S2Us) present in tRNA play an important role in tuning the translation process through codon-anticodon interactions. The enhanced thermodynamic stability of S2U-containing RNA duplexes and the preferred S2U-A versus S2U-G base pairing are appreciated characteristics of S2U-modified molecular probes. Recently, we have demonstrated that 2-thiouridine (alone or within an RNA chain) is predominantly transformed under oxidative stress conditions to 4-pyrimidinone riboside (H2U) and not to uridine. Due to the important biological functions and various biotechnological applications for sulfur-containing nucleic acids, we compared the thermodynamic stabilities of duplexes containing desulfured products with those of 2-thiouracil-modified RNA and DNA duplexes. Differential scanning calorimetry experiments and theoretical calculations demonstrate that upon 2-thiouracil desulfuration to 4-pyrimidinone, the preferred base pairing of S2U with adenosine is lost, with preferred base pairing with guanosine observed instead. Therefore, biological processes and in vitro assays in which oxidative desulfuration of 2-thiouracil-containing components occurs may be altered. Moreover, we propose that the H2U-G base pair is a suitable model for investigation of the preferred recognition of 3'-G-ending versus A-ending codons by tRNA wobble nucleosides, which may adopt a 4-pyrimidinone-type structural motif.
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Affiliation(s)
- Elzbieta Sochacka
- Institute of Organic Chemistry, Technical University of Lodz, Zeromskiego 116, 90-924 Lodz, Poland
| | - Roman H Szczepanowski
- International Institute of Molecular and Cell Biology, Ks. J. Trojdena 4, 02-109 Warsaw, Poland
| | - Marek Cypryk
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland
| | - Milena Sobczak
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland
| | - Magdalena Janicka
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland
| | - Karina Kraszewska
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland
| | - Paulina Bartos
- Institute of Organic Chemistry, Technical University of Lodz, Zeromskiego 116, 90-924 Lodz, Poland
| | - Anna Chwialkowska
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland
| | - Barbara Nawrot
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland
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19
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Waleń T, Chojnowski G, Gierski P, Bujnicki JM. ClaRNA: a classifier of contacts in RNA 3D structures based on a comparative analysis of various classification schemes. Nucleic Acids Res 2014; 42:e151. [PMID: 25159614 PMCID: PMC4231730 DOI: 10.1093/nar/gku765] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The understanding of folding and function of RNA molecules depends on the identification and classification of interactions between ribonucleotide residues. We developed a new method named ClaRNA for computational classification of contacts in RNA 3D structures. Unique features of the program are the ability to identify imperfect contacts and to process coarse-grained models. Each doublet of spatially close ribonucleotide residues in a query structure is compared to clusters of reference doublets obtained by analysis of a large number of experimentally determined RNA structures, and assigned a score that describes its similarity to one or more known types of contacts, including pairing, stacking, base–phosphate and base–ribose interactions. The accuracy of ClaRNA is 0.997 for canonical base pairs, 0.983 for non-canonical pairs and 0.961 for stacking interactions. The generalized squared correlation coefficient (GC2) for ClaRNA is 0.969 for canonical base pairs, 0.638 for non-canonical pairs and 0.824 for stacking interactions. The classifier can be easily extended to include new types of spatial relationships between pairs or larger assemblies of nucleotide residues. ClaRNA is freely available via a web server that includes an extensive set of tools for processing and visualizing structural information about RNA molecules.
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Affiliation(s)
- Tomasz Waleń
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Warsaw 02-109, Poland Faculty of Mathematics, Informatics and Mechanics, University of Warsaw, Warsaw 02-097, Poland
| | - Grzegorz Chojnowski
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Warsaw 02-109, Poland
| | - Przemysław Gierski
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Warsaw 02-109, Poland
| | - Janusz M Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Warsaw 02-109, Poland Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
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20
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Brovarets' OO, Hovorun DM. Atomistic nature of the DPT tautomerisation of the biologically important C·C* DNA base mispair containing amino and imino tautomers of cytosine: a QM and QTAIM approach. Phys Chem Chem Phys 2014; 15:20091-104. [PMID: 24154739 DOI: 10.1039/c3cp52644e] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A theoretical study of tautomerisation of the biologically important cytosine·cytosine* (C·C*) DNA mismatch with a propeller-like structure (|C4N3N3C4| = 32.4°; C1 symmetry) and cis-oriented N1H glycosidic bonds, formed by the amino and imino tautomers of the C nucleobase, via the asynchronous concerted double proton transfer (DPT) along two H-bonds through the transition state (TSC·C*↔C*·C) (|C4N3N3C4| = 48.5°; C1 symmetry) into the C*·C mispair was carried out for the first time. It was established that the C·C*/C*·C DNA base mispair is associated by the antiparallel N4H···N4 (6.66 kcal mol(-1)), N3H···N3 (6.47 kcal mol(-1)) H-bonds and the O2···O2 van der Waals (vdW) contact (0.33 kcal mol(-1)), while the zwitterionic TSC·C*↔C*·C is stabilized by the parallel N4(+)H···N4(-) (13.55 kcal mol(-1)), N3(+)H···N3(-) (13.20 kcal mol(-1)) H-bonds and the O2(+)···O2(-) vdW contact (0.60 kcal mol(-1)). It was shown that the C·C* ↔ C*·C tautomerisation via the DPT is assisted by the O2···O2 vdW contact, that in contrast to the two others N4H···N4 and N3H···N3 H-bonds exists along the entire intrinsic reaction coordinate (IRC) range. The positive values of the Grunenberg's compliance constants (30.919 and 21.384 Å mdyn(-1) for C·C*/C*·C and TSC·C*↔C*·C, respectively) indicate that the O2···O2 vdW contact is a stabilizing closed-shell interaction. It was found that the middle N3H···N3 H-bond is anti-cooperative with the upper N4H···N4 H-bond and cooperative with the lower O2···O2 vdW contact. The 9 key points, which can be considered as electron-topological "fingerprints" of the asynchronous concerted C·C* ↔ C*·C tautomerisation process via the DPT were revealed along the IRC and examined in detail. It was shown that the C·C*/C*·C base mispair is a thermodynamically and dynamically stable structure. Its lifetime is equal to 1.53 × 10(-7) s at the MP2/cc-pVQZ//B3LYP/6-311++G(d,p) level of theory in vacuum. All 6 low-frequency intermolecular vibrations are able to develop during this time span.
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Affiliation(s)
- Ol'ha O Brovarets'
- Department of Molecular and Quantum Biophysics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 150 Akademika Zabolotnoho Str., 03680 Kyiv, Ukraine.
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21
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Abstract
Helices are an essential element in defining the three-dimensional architecture of structured RNAs. While internal basepairs in a canonical helix stack on both sides, the ends of the helix stack on only one side and are exposed to the loop side, thus susceptible to fraying unless they are protected. While coaxial stacking has long been known to stabilize helix ends by directly stacking two canonical helices coaxially, based on analysis of helix-loop junctions in RNA crystal structures, herein we describe helix capping, topological stacking of a helix end with a basepair or an unpaired nucleotide from the loop side, which in turn protects helix ends. Beyond the topological protection of helix ends against fraying, helix capping should confer greater stability onto the resulting composite helices. Our analysis also reveals that this general motif is associated with the formation of tertiary structure interactions. Greater knowledge about the dynamics at the helix-junctions in the secondary structure should enhance the prediction of RNA secondary structure with a richer set of energetic rules and help better understand the folding of a secondary structure into its three-dimensional structure. These together suggest that helix capping likely play a fundamental role in driving RNA folding.
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Affiliation(s)
- Jung C. Lee
- BioMolecular Engineering Program, Physics and Chemistry Department, Milwaukee School of Engineering, Milwaukee, Wisconsin, United States of America
- * E-mail: (JCL); (RRG)
| | - Robin R. Gutell
- Center for Computational Biology and Bioinformatics, Institute for Cellular and Molecular Biology, and Section of Integrative Biology, the University of Texas at Austin, Austin, Texas, United States of America
- * E-mail: (JCL); (RRG)
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22
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Sun S, Wang J, Mu D, Wang J, Bao Y, Qiao B, Peng X. A heterodinuclear RuIr metal complex for direct imaging of rRNA in living cells. Chem Commun (Camb) 2014; 50:9149-52. [DOI: 10.1039/c4cc04501g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A novel dual luminescence heterodinuclear RuIr complex for RNA detection was developed, which was successfully used to image rRNA in living cells.
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Affiliation(s)
- Shiguo Sun
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian, China
| | - Jitao Wang
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian, China
| | - Daozhou Mu
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian, China
| | - Jingyun Wang
- School of Life Science and Biotechnology
- Dalian University of Technology
- Dalian, China
| | - Yongming Bao
- School of Life Science and Biotechnology
- Dalian University of Technology
- Dalian, China
| | - Bo Qiao
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian, China
| | - Xiaojun Peng
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian, China
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23
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Brovarets’ OO, Zhurakivsky RO, Hovorun DM. Structural, energetic and tautomeric properties of the T·T∗/T∗·T DNA mismatch involving mutagenic tautomer of thymine: A QM and QTAIM insight. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2013.12.034] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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24
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Brovarets' OO, Zhurakivsky RO, Hovorun DM. Is the DPT tautomerization of the long A·G Watson-Crick DNA base mispair a source of the adenine and guanine mutagenic tautomers? A QM and QTAIM response to the biologically important question. J Comput Chem 2013; 35:451-66. [PMID: 24382756 DOI: 10.1002/jcc.23515] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Revised: 11/12/2013] [Accepted: 11/30/2013] [Indexed: 02/04/2023]
Abstract
Herein, we first address the question posed in the title by establishing the tautomerization trajectory via the double proton transfer of the adenine·guanine (A·G) DNA base mispair formed by the canonical tautomers of the A and G bases into the A*·G* DNA base mispair, involving mutagenic tautomers, with the use of the quantum-mechanical calculations and quantum theory of atoms in molecules (QTAIM). It was detected that the A·G ↔ A*·G* tautomerization proceeds through the asynchronous concerted mechanism. It was revealed that the A·G base mispair is stabilized by the N6H···O6 (5.68) and N1H···N1 (6.51) hydrogen bonds (H-bonds) and the N2H···HC2 dihydrogen bond (DH-bond) (0.68 kcal·mol(-1) ), whereas the A*·G* base mispair-by the O6H···N6 (10.88), N1H···N1 (7.01) and C2H···N2 H-bonds (0.42 kcal·mol(-1) ). The N2H···HC2 DH-bond smoothly and without bifurcation transforms into the C2H···N2 H-bond at the IRC = -10.07 Bohr in the course of the A·G ↔ A*·G* tautomerization. Using the sweeps of the energies of the intermolecular H-bonds, it was observed that the N6H···O6 H-bond is anticooperative to the two others-N1H···N1 and N2H···HC2 in the A·G base mispair, while the latters are significantly cooperative, mutually strengthening each other. In opposite, all three O6H···N6, N1H···N1, and C2H···N2 H-bonds are cooperative in the A*·G* base mispair. All in all, we established the dynamical instability of the А*·G* base mispair with a short lifetime (4.83·10(-14) s), enabling it not to be deemed feasible source of the A* and G* mutagenic tautomers of the DNA bases. The small lifetime of the А*·G* base mispair is predetermined by the negative value of the Gibbs free energy for the A*·G* → A·G transition. Moreover, all of the six low-frequency intermolecular vibrations cannot develop during this lifetime that additionally confirms the aforementioned results. Thus, the A*·G* base mispair cannot be considered as a source of the mutagenic tautomers of the DNA bases, as the A·G base mispair dissociates during DNA replication exceptionally into the A and G monomers in the canonical tautomeric form.
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Affiliation(s)
- Ol'ha O Brovarets'
- Department of Molecular and Quantum Biophysics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 150 Akademika Zabolotnoho Str., 03680, Kyiv, Ukraine ; Research and Educational Center "State Key Laboratory of Molecular and Cell Biology", 150 Akademika Zabolotnoho Str., 03680, Kyiv, Ukraine; Department of Molecular Biology, Biotechnology and Biophysics, Institute of High Technologies, Taras Shevchenko National University of Kyiv, 2-h Akademika Hlushkova Ave., 03022, Kyiv, Ukraine
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Dibrov SM, Parsons J, Carnevali M, Zhou S, Rynearson KD, Ding K, Garcia Sega E, Brunn ND, Boerneke MA, Castaldi MP, Hermann T. Hepatitis C virus translation inhibitors targeting the internal ribosomal entry site. J Med Chem 2013; 57:1694-707. [PMID: 24138284 DOI: 10.1021/jm401312n] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The internal ribosome entry site (IRES) in the 5' untranslated region (UTR) of the hepatitis C virus (HCV) genome initiates translation of the viral polyprotein precursor. The unique structure and high sequence conservation of the 5' UTR render the IRES RNA a potential target for the development of selective viral translation inhibitors. Here, we provide an overview of approaches to block HCV IRES function by nucleic acid, peptide, and small molecule ligands. Emphasis will be given to the IRES subdomain IIa, which currently is the most advanced target for small molecule inhibitors of HCV translation. The subdomain IIa behaves as an RNA conformational switch. Selective ligands act as translation inhibitors by locking the conformation of the RNA switch. We review synthetic procedures for inhibitors as well as structural and functional studies of the subdomain IIa target and its ligand complexes.
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Affiliation(s)
- Sergey M Dibrov
- Department of Chemistry and Biochemistry, University of California, San Diego , 9500 Gilman Drive, La Jolla, California 92093, United States
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Sahu PK, Srinivasadesikan V, Jhong ML, Lee SL. Model calculations for the base-pairing specificity of mutagenic exocyclic DNA adduct 1,N 6-ethenoadenine. Struct Chem 2013. [DOI: 10.1007/s11224-013-0318-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Brovarets' OO, Hovorun DM. Atomistic understanding of the C·T mismatched DNA base pair tautomerization via the DPT: QM and QTAIM computational approaches. J Comput Chem 2013; 34:2577-90. [PMID: 23955922 DOI: 10.1002/jcc.23412] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 07/25/2013] [Indexed: 11/09/2022]
Abstract
It was established that the cytosine·thymine (C·T) mismatched DNA base pair with cis-oriented N1H glycosidic bonds has propeller-like structure (|N3C4C4N3| = 38.4°), which is stabilized by three specific intermolecular interactions-two antiparallel N4H…O4 (5.19 kcal mol(-1)) and N3H…N3 (6.33 kcal mol(-1)) H-bonds and a van der Waals (vdW) contact O2…O2 (0.32 kcal mol(-1)). The C·T base mispair is thermodynamically stable structure (ΔG(int) = -1.54 kcal mol(-1) ) and even slightly more stable than the A·T Watson-Crick DNA base pair (ΔG(int) = -1.43 kcal mol(-1)) at the room temperature. It was shown that the C·T ↔ C*·T* tautomerization via the double proton transfer (DPT) is assisted by the O2…O2 vdW contact along the entire range of the intrinsic reaction coordinate (IRC). The positive value of the Grunenberg's compliance constants (31.186, 30.265, and 22.166 Å/mdyn for the C·T, C*·T*, and TS(C·T ↔ C*·T*), respectively) proves that the O2…O2 vdW contact is a stabilizing interaction. Based on the sweeps of the H-bond energies, it was found that the N4H…O4/O4H…N4, and N3H…N3 H-bonds in the C·T and C*·T* base pairs are anticooperative and weaken each other, whereas the middle N3H…N3 H-bond and the O2…O2 vdW contact are cooperative and mutually reinforce each other. It was found that the tautomerization of the C·T base mispair through the DPT is concerted and asynchronous reaction that proceeds via the TS(C·T ↔ C*·T*) stabilized by the loosened N4-H-O4 covalent bridge, N3H…N3 H-bond (9.67 kcal mol(-1) ) and O2…O2 vdW contact (0.41 kcal mol(-1) ). The nine key points, describing the evolution of the C·T ↔ C*·T* tautomerization via the DPT, were detected and completely investigated along the IRC. The C*·T* mispair was revealed to be the dynamically unstable structure with a lifetime 2.13·× 10(-13) s. In this case, as for the A·T Watson-Crick DNA base pair, activates the mechanism of the quantum protection of the C·T DNA base mispair from its spontaneous mutagenic tautomerization through the DPT.
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Affiliation(s)
- Ol'ha O Brovarets'
- Department of Molecular and Quantum Biophysics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 150 Zabolotnoho Str., Kyiv, 03680, Ukraine; Research and Educational Center, State Key Laboratory of Molecular and Cell Biology, 150 Zabolotnoho Str., Kyiv, 03680, Ukraine; Department of Molecular Biotechnology and Bioinformatics, Institute of High Technologies, Taras Shevchenko National University of Kyiv, 2 Hlushkova Ave., Kyiv, 03022, Ukraine
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Ananth P, Goldsmith G, Yathindra N. An innate twist between Crick's wobble and Watson-Crick base pairs. RNA (NEW YORK, N.Y.) 2013; 19:1038-1053. [PMID: 23861536 PMCID: PMC3708525 DOI: 10.1261/rna.036905.112] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Non-Watson-Crick pairs like the G·U wobble are frequent in RNA duplexes. Their geometric dissimilarity (nonisostericity) with the Watson-Crick base pairs and among themselves imparts structural variations decisive for biological functions. Through a novel circular representation of base pairs, a simple and general metric scheme for quantification of base-pair nonisostericity, in terms of residual twist and radial difference that can also envisage its mechanistic effect, is proposed. The scheme is exemplified by G·U and U·G wobble pairs, and their predicable local effects on helical twist angle are validated by MD simulations. New insights into a possible rationale for contextual occurrence of G·U and other non-WC pairs, as well as the influence of a G·U pair on other non-Watson-Crick pair neighborhood and RNA-protein interactions are obtained from analysis of crystal structure data. A few instances of RNA-protein interactions along the major groove are documented in addition to the well-recognized interaction of the G·U pair along the minor groove. The nonisostericity-mediated influence of wobble pairs for facilitating helical packing through long-range interactions in ribosomal RNAs is also reviewed.
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Halder S, Bhattacharyya D. RNA structure and dynamics: a base pairing perspective. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2013; 113:264-83. [PMID: 23891726 DOI: 10.1016/j.pbiomolbio.2013.07.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 06/25/2013] [Accepted: 07/16/2013] [Indexed: 12/12/2022]
Abstract
RNA is now known to possess various structural, regulatory and enzymatic functions for survival of cellular organisms. Functional RNA structures are generally created by three-dimensional organization of small structural motifs, formed by base pairing between self-complementary sequences from different parts of the RNA chain. In addition to the canonical Watson-Crick or wobble base pairs, several non-canonical base pairs are found to be crucial to the structural organization of RNA molecules. They appear within different structural motifs and are found to stabilize the molecule through long-range intra-molecular interactions between basic structural motifs like double helices and loops. These base pairs also impart functional variation to the minor groove of A-form RNA helices, thus forming anchoring site for metabolites and ligands. Non-canonical base pairs are formed by edge-to-edge hydrogen bonding interactions between the bases. A large number of theoretical studies have been done to detect and analyze these non-canonical base pairs within crystal or NMR derived structures of different functional RNA. Theoretical studies of these isolated base pairs using ab initio quantum chemical methods as well as molecular dynamics simulations of larger fragments have also established that many of these non-canonical base pairs are as stable as the canonical Watson-Crick base pairs. This review focuses on the various structural aspects of non-canonical base pairs in the organization of RNA molecules and the possible applications of these base pairs in predicting RNA structures with more accuracy.
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Affiliation(s)
- Sukanya Halder
- Biophysics division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700 064, India
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30
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Brovarets’ OO, Yurenko YP, Hovorun DM. Intermolecular CH···O/N H-bonds in the biologically important pairs of natural nucleobases: a thorough quantum-chemical study. J Biomol Struct Dyn 2013; 32:993-1022. [PMID: 23730732 DOI: 10.1080/07391102.2013.799439] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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31
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Brovarets’ OO, Zhurakivsky RO, Hovorun DM. DPT tautomerization of the long A∙A* Watson-Crick base pair formed by the amino and imino tautomers of adenine: combined QM and QTAIM investigation. J Mol Model 2013; 19:4223-37. [DOI: 10.1007/s00894-013-1880-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Accepted: 05/02/2013] [Indexed: 12/01/2022]
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Shang L, Xu W, Ozer S, Gutell RR. Structural constraints identified with covariation analysis in ribosomal RNA. PLoS One 2012; 7:e39383. [PMID: 22724009 PMCID: PMC3378556 DOI: 10.1371/journal.pone.0039383] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 05/24/2012] [Indexed: 11/19/2022] Open
Abstract
Covariation analysis is used to identify those positions with similar patterns of sequence variation in an alignment of RNA sequences. These constraints on the evolution of two positions are usually associated with a base pair in a helix. While mutual information (MI) has been used to accurately predict an RNA secondary structure and a few of its tertiary interactions, early studies revealed that phylogenetic event counting methods are more sensitive and provide extra confidence in the prediction of base pairs. We developed a novel and powerful phylogenetic events counting method (PEC) for quantifying positional covariation with the Gutell lab’s new RNA Comparative Analysis Database (rCAD). The PEC and MI-based methods each identify unique base pairs, and jointly identify many other base pairs. In total, both methods in combination with an N-best and helix-extension strategy identify the maximal number of base pairs. While covariation methods have effectively and accurately predicted RNAs secondary structure, only a few tertiary structure base pairs have been identified. Analysis presented herein and at the Gutell lab’s Comparative RNA Web (CRW) Site reveal that the majority of these latter base pairs do not covary with one another. However, covariation analysis does reveal a weaker although significant covariation between sets of nucleotides that are in proximity in the three-dimensional RNA structure. This reveals that covariation analysis identifies other types of structural constraints beyond the two nucleotides that form a base pair.
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MESH Headings
- Algorithms
- Base Pairing
- Computational Biology/methods
- Nucleic Acid Conformation
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/genetics
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 23S/chemistry
- RNA, Ribosomal, 23S/genetics
- RNA, Ribosomal, 5S/chemistry
- RNA, Ribosomal, 5S/genetics
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Affiliation(s)
- Lei Shang
- Institute for Cellular and Molecular Biology, Center for Computational Biology and Bioinformatics, The University of Texas at Austin, Austin, Texas, United States of America
| | - Weijia Xu
- Texas Advanced Computing Center, The University of Texas at Austin, Austin, Texas, United States of America
| | - Stuart Ozer
- Microsoft Corporation, Redmond, Washington, United States of America
| | - Robin R. Gutell
- Institute for Cellular and Molecular Biology, Center for Computational Biology and Bioinformatics, The University of Texas at Austin, Austin, Texas, United States of America
- * E-mail:
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Goh GB, Knight JL, Brooks CL. Constant pH Molecular Dynamics Simulations of Nucleic Acids in Explicit Solvent. J Chem Theory Comput 2011; 8:36-46. [PMID: 22337595 DOI: 10.1021/ct2006314] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The nucleosides of adenine and cytosine have pKa values of 3.50 and 4.08, respectively, and are assumed to be unprotonated under physiological conditions. However, evidence from recent NMR and X-Ray crystallography studies has revealed the prevalence of protonated adenine and cytosine in RNA macromolecules. Such nucleotides with elevated pKa values may play a role in stabilizing RNA structure and participate in the mechanism of ribozyme catalysis. With the work presented here, we establish the framework and demonstrate the first constant pH MD simulations (CPHMD) for nucleic acids in explicit solvent in which the protonation state is coupled to the dynamical evolution of the RNA system via λ-dynamics. We adopt the new functional form λ(Nexp) for λ that was recently developed for Multi-Site λ-Dynamics (MSλD) and demonstrate good sampling characteristics in which rapid and frequent transitions between the protonated and unprotonated states at pH = pKa are achieved. Our calculated pKa values of simple nucleotides are in a good agreement with experimentally measured values, with a mean absolute error of 0.24 pKa units. This work demonstrates that CPHMD can be used as a powerful tool to investigate pH-dependent biological properties of RNA macromolecules.
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Affiliation(s)
- Garrett B Goh
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan 48109, United States
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Xu W, Wongsa A, Lee J, Shang L, Cannone JJ, Gutell RR. RNA2DMap: A Visual Exploration Tool of the Information in RNA's Higher-Order Structure. PROCEEDINGS. IEEE INTERNATIONAL CONFERENCE ON BIOINFORMATICS AND BIOMEDICINE 2011:613-617. [PMID: 22983261 DOI: 10.1109/bibm.2011.60] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A new and emerging paradigm in molecular biology is revealing that RNA is implicated in nearly every aspect of the metabolism in the cell. To enhance our understanding of the function of these RNA molecules in the cell, it is essential that we have a complete understanding of their higher-order structures. While many computational tools have been developed to predict and analyse these higher-order RNA structures, few are able to visualize them for analytical purposes. In this paper, we present an interactive visualization tool of the secondary structure of RNA, named RNA2DMap. This program enables multiple-dimensions of information about RNA structure to be selected, customized and displayed to visually identify patterns and relationships. RNA2DMap facilitates the comparative analysis and understanding of RNAs that cannot be readily obtained with other graphical or text output from computer programs. Three use cases are presented to illustrate how RNA2DMap aids structural analysis.
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Affiliation(s)
- Weijia Xu
- Texas Advanced Computing Center The University of Texas at Austin Austin, Texas, USA
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35
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Kuchin S. Covering all the bases in genetics: simple shorthands and diagrams for teaching base pairing to biology undergraduates. JOURNAL OF MICROBIOLOGY & BIOLOGY EDUCATION 2011; 12:64-66. [PMID: 23653747 PMCID: PMC3577215 DOI: 10.1128/jmbe.v12i1.267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Explaining base pairing is an important element in teaching undergraduate genetics. I propose a teaching approach that aims to close the gap between the mantra “A pairs with T, and G pairs with C” and the “intimidating” chemical diagrams. The approach offers a set of simple “shorthands” for the key bases that can be used to quickly deduce all canonical and wobble pairs that the students need to know. The approach can be further developed to analyze mutagenic mismatch pairing.
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Affiliation(s)
- Sergei Kuchin
- Corresponding author. Mailing address: Department of Biological Sciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Ave., Milwaukee, WI 53211. Phone: (414) 229-3135. Fax: (414) 229-3926. E-mail:
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36
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Zhang X, Guo C, Zhang W, Cao H, Xie H, Wang K, Liu C. A folding "framework structure" of Tetrahymena group I intron. J Theor Biol 2010; 267:495-501. [PMID: 20858505 DOI: 10.1016/j.jtbi.2010.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 08/16/2010] [Accepted: 09/01/2010] [Indexed: 10/19/2022]
Abstract
We have published the dynamic extended folding (DEF) method, which is a RNA secondary structure prediction approach-to simulate the in vivo RNA co-transcriptional folding process. In order to verify the reliability of the method, we selected the X-ray-determined Tetrahymena group I intron as a sample to construct the framework of its folding secondary structure. Our prediction coincides well with the secondary structure predicted by T.R. Cech and the X-ray diffraction crystal structure determined by Lehnert V. Our results show that the DEF framework structure of Tetrahymena group I intron reflects its function sites in a concise and straightforward manner, and the scope of the simulation was expanded.
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Affiliation(s)
- Xi Zhang
- Modern Biological Research Center, Yunnan University, Kunming 650091, China
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37
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Novel method of cell-free in vitro synthesis of the human fibroblast growth factor 1 gene. J Biomed Biotechnol 2010; 2010. [PMID: 20706664 PMCID: PMC2913909 DOI: 10.1155/2010/971340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Accepted: 06/16/2010] [Indexed: 11/17/2022] Open
Abstract
Recombinant DNA projects generally involve cell-based gene cloning. However, because template DNA is not always readily available, in vitro chemical synthesis of complete genes from DNA oligonucleotides is becoming the preferred method for cloning. This article describes a new, rapid procedure based on Taq polymerase for the precise assembly of DNA oligonucleotides to yield the complete human fibroblast growth factor 1 (FGF1) gene, which is 468 bp long and has a G+C content of 51.5%. The new method involved two steps: (1) the design of the DNA oligonucleotides to be assembled and (2) the assembly of multiple oligonucleotides by PCR to generate the whole FGF1 gene. The procedure lasted a total of only 2 days, compared with 2 weeks for the conventional procedure. This method of gene synthesis is expected to facilitate various kinds of complex genetic engineering projects that require rapid gene amplification, such as cell-free whole-DNA library construction, as well as the construction of new genes or genes that contain any mutation, restriction site, or DNA tag.
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38
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Islam MM, Suresh Kumar G. RNA-binding potential of protoberberine alkaloids: spectroscopic and calorimetric studies on the binding of berberine, palmatine, and coralyne to protonated RNA structures. DNA Cell Biol 2009; 28:637-50. [PMID: 19715476 DOI: 10.1089/dna.2009.0930] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Interaction of the protoberberine alkaloids berberine, palmatine, and coralyne with the two double-stranded RNA homopolymers of cytidine-guanosine (CG) and inosine-cytidine (IC) sequences in the protonated conformation was investigated using various biophysical techniques. All the three alkaloids bound polyC(+)G in a cooperative way. The binding of coralyne to both the polyribonucleotides was stronger than that of berberine and palmatine. Evidence for the intercalative binding of coralyne was revealed from fluorescence quenching studies. Isothermal titration calorimetry results suggested that the binding of berberine to both the polymers and palmatine to polyIC(+) was very weak while that of palmatine and coralyne to polyC(+)G and polyIC(+) was predominantly entropy driven. Circular dichroic results provided evidence for the perturbation of the RNA conformation with the bound coralyne in a more deeply intercalated position compared to berberine and palmatine as revealed by induced circular dichroism peaks. Taken together, the present study suggests that planarity of coralyne results in a more favorable and stronger binding to the double-stranded RNA conformations compared to berberine and palmatine that may potentiate its use in RNA-targeted drug design.
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Affiliation(s)
- M M Islam
- Biophysical Chemistry Laboratory, Indian Institute of Chemical Biology, Council of Scientific and Industrial Research, Kolkata 700032, India.
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39
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Jain R, Nair DT, Johnson RE, Prakash L, Prakash S, Aggarwal AK. Replication across template T/U by human DNA polymerase-iota. Structure 2009; 17:974-80. [PMID: 19604477 DOI: 10.1016/j.str.2009.04.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 04/21/2009] [Accepted: 04/29/2009] [Indexed: 10/20/2022]
Abstract
Human DNA polymerase-iota (Poliota) incorporates correct nucleotides opposite template purines with a much higher efficiency and fidelity than opposite template pyrimidines. In fact, the fidelity opposite template T is so poor that Poliota inserts an incorrect dGTP approximately 10 times better than it inserts the correct dATP. We determine here how a template T/U is accommodated in the Poliota active site and why a G is incorporated more efficiently than an A. We show that in the absence of incoming dATP or dGTP (binary complex), template T/U exists in both syn and anti conformations, but in the presence of dATP or dGTP (ternary complexes), template T/U is predominantly in the anti conformation. We also show that dATP and dGTP insert differently opposite template T/U, and that the basis of selection of dGTP over dATP is a hydrogen bond between the N2 amino group of dGTP and Gln59 of Poliota.
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Affiliation(s)
- Rinku Jain
- Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
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40
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Li Y, Dong M, Otzen DE, Yao Y, Liu B, Besenbacher F, Mamdouh W. Influence of tunable external stimuli on the self-assembly of guanosine supramolecular nanostructures studied by atomic force microscope. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:13432-13437. [PMID: 19499943 DOI: 10.1021/la900640f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The self-assembly of guanosine (G) molecules on solid surfaces is investigated by tapping-mode atomic force microscopy (AFM) upon controlling and introducing external factors (stimuli) to the G stock solution such as incubation time, presence/absence of metal cations, and mechanical shaking. Surprisingly, at different stages of incubation time at room temperature and in the absence of any metal cations in the G stock solution, which are known to be one of the governing factors in forming G-nanostructures, two assembly pathways resulting into two distinct supramolecular nanostructures were revealed. Astonishingly, by introducing a mechanical shaking of the tube containing the G stock solution, one-dimensional (1D) wires of G molecules are observed by AFM, and very interestingly, novel "branched" supramolecular nanostructures are formed. We have also observed that the later branched G nanostructures can grow further into a two-dimensional (2D) thin film by increasing the incubation time of the G stock solution at room temperature after it is exposed to the external mechanical stimuli. The self-assembled nanostructures of G molecules are changed significantly by tuning the assembly conditions, which show that it is indeed possible to grow complex 2D nanostructures from simple nucleoside molecules.
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Affiliation(s)
- Yinli Li
- Institute of Photo-Biophysics, Physics and Electronics Department, Henan University, 475004, Kaifeng, China
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41
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Santini GPH, Cognet JAH, Xu D, Singarapu KK, Hervé du Penhoat C. Nucleic acid folding determined by mesoscale modeling and NMR spectroscopy: solution structure of d(GCGAAAGC). J Phys Chem B 2009; 113:6881-93. [PMID: 19374420 DOI: 10.1021/jp8100656] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Determination of DNA solution structure is a difficult task even with the high-sensitivity method used here based on simulated annealing with 35 restraints/residue (Cryoprobe 750 MHz NMR). The conformations of both the phosphodiester linkages and the dinucleotide segment encompassing the sharp turn in single-stranded DNA are often underdetermined. To obtain higher quality structures of a DNA GNRA loop, 5'-d(GCGAAAGC)-3', we have used a mesoscopic molecular modeling approach, called Biopolymer Chain Elasticity (BCE), to provide reference conformations. By construction, these models are the least deformed hairpin loop conformation derived from canonical B-DNA at the nucleotide level. We have further explored this molecular conformation at the torsion angle level with AMBER molecular mechanics using different possible (epsilon,zeta) constraints to interpret the 31P NMR data. This combined approach yields a more accurate molecular conformation, compatible with all the NMR data, than each method taken separately, NMR/DYANA or BCE/AMBER. In agreement with the principle of minimal deformation of the backbone, the hairpin motif is stabilized by maximal base-stacking interactions on both the 5'- and 3'-sides and by a sheared G.A mismatch base pair between the first and last loop nucleotides. The sharp turn is located between the third and fourth loop nucleotides, and only two torsion angles beta6 and gamma6 deviate strongly with respect to canonical B-DNA structure. Two other torsion angle pairs epsilon3,zeta3 and epsilon5,zeta5 exhibit the newly recognized stable conformation BIIzeta+ (-70 degrees, 140 degrees). This combined approach has proven to be useful for the interpretation of an unusual 31P chemical shift in the 5'-d(GCGAAAGC)-3' hairpin.
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Affiliation(s)
- Guillaume P H Santini
- Laboratoire de Biophysique Moleculaire, Cellulaire et Tissulaire, UMR 7033 CNRS, Universite Pierre et Marie Curie Paris 6, Genopole Campus 1, 5 rue Henri Desbrueres, Evry 91030, France
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42
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Wu JC, Gardner DP, Ozer S, Gutell RR, Ren P. Correlation of RNA secondary structure statistics with thermodynamic stability and applications to folding. J Mol Biol 2009; 391:769-83. [PMID: 19540243 DOI: 10.1016/j.jmb.2009.06.036] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 06/05/2009] [Accepted: 06/12/2009] [Indexed: 11/15/2022]
Abstract
The accurate prediction of the secondary and tertiary structure of an RNA with different folding algorithms is dependent on several factors, including the energy functions. However, an RNA higher-order structure cannot be predicted accurately from its sequence based on a limited set of energy parameters. The inter- and intramolecular forces between this RNA and other small molecules and macromolecules, in addition to other factors in the cell such as pH, ionic strength, and temperature, influence the complex dynamics associated with transition of a single stranded RNA to its secondary and tertiary structure. Since all of the factors that affect the formation of an RNAs 3D structure cannot be determined experimentally, statistically derived potential energy has been used in the prediction of protein structure. In the current work, we evaluate the statistical free energy of various secondary structure motifs, including base-pair stacks, hairpin loops, and internal loops, using their statistical frequency obtained from the comparative analysis of more than 50,000 RNA sequences stored in the RNA Comparative Analysis Database (rCAD) at the Comparative RNA Web (CRW) Site. Statistical energy was computed from the structural statistics for several datasets. While the statistical energy for a base-pair stack correlates with experimentally derived free energy values, suggesting a Boltzmann-like distribution, variation is observed between different molecules and their location on the phylogenetic tree of life. Our statistical energy values calculated for several structural elements were utilized in the Mfold RNA-folding algorithm. The combined statistical energy values for base-pair stacks, hairpins and internal loop flanks result in a significant improvement in the accuracy of secondary structure prediction; the hairpin flanks contribute the most.
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Affiliation(s)
- Johnny C Wu
- Department of Biomedical Engineering, University of Texas at Austin, 78712-1062, USA
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43
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Bilbille Y, Vendeix FAP, Guenther R, Malkiewicz A, Ariza X, Vilarrasa J, Agris PF. The structure of the human tRNALys3 anticodon bound to the HIV genome is stabilized by modified nucleosides and adjacent mismatch base pairs. Nucleic Acids Res 2009; 37:3342-53. [PMID: 19324888 PMCID: PMC2691828 DOI: 10.1093/nar/gkp187] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Replication of human immunodeficiency virus (HIV) requires base pairing of the reverse transcriptase primer, human tRNALys3, to the viral RNA. Although the major complementary base pairing occurs between the HIV primer binding sequence (PBS) and the tRNA's 3′-terminus, an important discriminatory, secondary contact occurs between the viral A-rich Loop I, 5′-adjacent to the PBS, and the modified, U-rich anticodon domain of tRNALys3. The importance of individual and combined anticodon modifications to the tRNA/HIV-1 Loop I RNA's interaction was determined. The thermal stabilities of variously modified tRNA anticodon region sequences bound to the Loop I of viral sub(sero)types G and B were analyzed and the structure of one duplex containing two modified nucleosides was determined using NMR spectroscopy and restrained molecular dynamics. The modifications 2-thiouridine, s2U34, and pseudouridine, Ψ39, appreciably stabilized the interaction of the anticodon region with the viral subtype G and B RNAs. The structure of the duplex results in two coaxially stacked A-form RNA stems separated by two mismatched base pairs, U162•Ψ39 and G163•A38, that maintained a reasonable A-form helix diameter. The tRNA's s2U34 stabilized the interaction between the A-rich HIV Loop I sequence and the U-rich anticodon, whereas the tRNA's Ψ39 stabilized the adjacent mismatched pairs.
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Affiliation(s)
- Yann Bilbille
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695-7622, USA
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44
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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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45
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Jaeger L, Verzemnieks EJ, Geary C. The UA_handle: a versatile submotif in stable RNA architectures. Nucleic Acids Res 2008; 37:215-30. [PMID: 19036788 PMCID: PMC2615604 DOI: 10.1093/nar/gkn911] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Stable RNAs are modular and hierarchical 3D architectures taking advantage of recurrent structural motifs to form extensive non-covalent tertiary interactions. Sequence and atomic structure analysis has revealed a novel submotif involving a minimal set of five nucleotides, termed the UA_handle motif (5'XU/AN(n)X3'). It consists of a U:A Watson-Crick: Hoogsteen trans base pair stacked over a classic Watson-Crick base pair, and a bulge of one or more nucleotides that can act as a handle for making different types of long-range interactions. This motif is one of the most versatile building blocks identified in stable RNAs. It enters into the composition of numerous recurrent motifs of greater structural complexity such as the T-loop, the 11-nt receptor, the UAA/GAN and the G-ribo motifs. Several structural principles pertaining to RNA motifs are derived from our analysis. A limited set of basic submotifs can account for the formation of most structural motifs uncovered in ribosomal and stable RNAs. Structural motifs can act as structural scaffoldings and be functionally and topologically equivalent despite sequence and structural differences. The sequence network resulting from the structural relationships shared by these RNA motifs can be used as a proto-language for assisting prediction and rational design of RNA tertiary structures.
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Affiliation(s)
- Luc Jaeger
- Chemistry and Biochemistry Department, University of California, Santa Barbara, CA 93106-9510, USA.
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46
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Structural insights into the cyclin T1-Tat-TAR RNA transcription activation complex from EIAV. Nat Struct Mol Biol 2008; 15:1287-92. [PMID: 19029897 DOI: 10.1038/nsmb.1513] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Accepted: 10/14/2008] [Indexed: 11/08/2022]
Abstract
The replication of many retroviruses is mediated by a transcriptional activator protein, Tat, which activates RNA polymerase II at the level of transcription elongation. Tat interacts with Cyclin T1 of the positive transcription-elongation factor P-TEFb to recruit the transactivation-response TAR RNA, which acts as a promoter element in the transcribed 5' end of the viral long terminal repeat. Here we present the structure of the cyclin box domain of Cyclin T1 in complex with the Tat protein from the equine infectious anemia virus and its corresponding TAR RNA. The basic RNA-recognition motif of Tat adopts a helical structure whose flanking regions interact with a cyclin T-specific loop in the first cyclin box repeat. Together, both proteins coordinate the stem-loop structure of TAR. Our findings show that Tat binds to a surface on Cyclin T1 similar to where recognition motifs from substrate and inhibitor peptides were previously found to interact within Cdk-cyclin pairs.
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47
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Abstract
The BPS (http://bps.rutgers.edu) is a database of RNA base-pair structures, higher-order base interactions and isosteric pairs (base pairs with similar shape). The main functions of the BPS are to find and annotate the structural and chemical features of the Watson–Crick and non-Watson–Crick (noncanonical) base pairs in high-resolution RNA structures, and to provide a user-friendly interface to browse and search for the base pairs. The current database contains 91 265 bp and 3386 higher-order base interactions from 426 RNA crystal structures and 61 819 bp that fall into one of 17 different isosteric classes. The base-pair data can be accessed by searches of base-pair patterns, structure identifiers (IDs) and structural types. The BPS also includes an Atlas with representative images of the various base pairs, higher-order base interactions and isosteric pairs and links to statistical information about these groups of structures.
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Affiliation(s)
| | - Wilma K. Olson
- *To whom correspondence should be addressed. Tel: +1 732 445 3993; Fax: +1 732 445-5958;
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48
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Theimer CA, Jády BE, Chim N, Richard P, Breece KE, Kiss T, Feigon J. Structural and functional characterization of human telomerase RNA processing and cajal body localization signals. Mol Cell 2007; 27:869-81. [PMID: 17889661 DOI: 10.1016/j.molcel.2007.07.017] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Revised: 06/18/2007] [Accepted: 07/06/2007] [Indexed: 12/11/2022]
Abstract
The RNA component of human telomerase (hTR) includes H/ACA and CR7 domains required for 3' end processing, localization, and accumulation. The terminal loop of the CR7 domain contains the CAB box (ugAG) required for targeting of scaRNAs to Cajal bodies (CB) and an uncharacterized sequence required for accumulation and processing. To dissect out the contributions of the CR7 stem loop to hTR processing and localization, we solved the solution structures of the 3' terminal stem loops of hTR CR7 and U64 H/ACA snoRNA, and the 5' terminal stem loop of U85 C/D-H/ACA scaRNA. These structures, together with analysis of localization, processing, and accumulation of hTRs containing nucleotide substitutions in the CR7 domain, identified the sequence and structural requirements of the hTR processing and CB localization signals and showed that these signals are functionally independent. Further, 3' end processing was found to be a prerequisite for translocation of hTR to CBs.
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Affiliation(s)
- Carla A Theimer
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-1569, USA
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49
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Sykes MT, Levitt M. Simulations of RNA base pairs in a nanodroplet reveal solvation-dependent stability. Proc Natl Acad Sci U S A 2007; 104:12336-40. [PMID: 17636124 PMCID: PMC1920539 DOI: 10.1073/pnas.0705573104] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We show that RNA base pairs have variable stability depending on their degree of solvation. This finding has far-reaching biological implications for nucleic acid structure in a partially solvated cellular environment such as inside RNA-protein complexes. Molecular dynamics simulations of partially solvated Watson-Crick RNA base pairs show that whereas water serves to destabilize a base pair by competing for and disrupting base-base hydrogen bonds, when sufficient water molecules are present, fewer hydrogen bonds are available to disrupt the base pairs and the destabilization effect is reduced. The result is that base pairs exist at a stability minimum when solvated in between 20 and 100 water molecules, the upper limit of which corresponds to the approximate number of water molecules contained in the first hydration shell.
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Affiliation(s)
- Michael T. Sykes
- Department of Structural Biology, Stanford University School of Medicine, D100 Fairchild Building, Stanford, CA 94305
- *To whom correspondence may be addressed. E-mail: or
| | - Michael Levitt
- Department of Structural Biology, Stanford University School of Medicine, D100 Fairchild Building, Stanford, CA 94305
- *To whom correspondence may be addressed. E-mail: or
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50
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Tang CL, Alexov E, Pyle AM, Honig B. Calculation of pKas in RNA: on the structural origins and functional roles of protonated nucleotides. J Mol Biol 2006; 366:1475-96. [PMID: 17223134 DOI: 10.1016/j.jmb.2006.12.001] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 11/29/2006] [Accepted: 12/01/2006] [Indexed: 12/01/2022]
Abstract
pK(a) calculations based on the Poisson-Boltzmann equation have been widely used to study proteins and, more recently, DNA. However, much less attention has been paid to the calculation of pK(a) shifts in RNA. There is accumulating evidence that protonated nucleotides can stabilize RNA structure and participate in enzyme catalysis within ribozymes. Here, we calculate the pK(a) shifts of nucleotides in RNA structures using numerical solutions to the Poisson-Boltzmann equation. We find that significant shifts are predicted for several nucleotides in two catalytic RNAs, the hairpin ribozyme and the hepatitis delta virus ribozyme, and that the shifts are likely to be related to their functions. We explore how different structural environments shift the pK(a)s of nucleotides from their solution values. RNA structures appear to use two basic strategies to shift pK(a)s: (a) the formation of compact structural motifs with structurally-conserved, electrostatic interactions; and (b) the arrangement of the phosphodiester backbone to focus negative electrostatic potential in specific regions.
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Affiliation(s)
- Christopher L Tang
- Howard Hughes Medical Institute, Center for Computational Biology and Bioinformatics, Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
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