Gauri Misra Editor Basics of Biophysics

Total Page:16

File Type:pdf, Size:1020Kb

Gauri Misra Editor Basics of Biophysics Gauri Misra Editor Introduction to Biomolecular Structure and Biophysics Basics of Biophysics Introduction to Biomolecular Structure and Biophysics Gauri Misra Editor Introduction to Biomolecular Structure and Biophysics Basics of Biophysics Editor Gauri Misra Amity University Noida, Uttar Pradesh India ISBN 978-981-10-4967-5 ISBN 978-981-10-4968-2 (eBook) DOI 10.1007/978-981-10-4968-2 Library of Congress Control Number: 2017952062 # The Editor(s) (if applicable) and The Author(s) 2017 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Printed on acid-free paper This Springer imprint is published by Springer Nature The registered company is Springer Nature Singapore Pte Ltd. The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore Dedicated to The lotus feet of Shri Radha Krishna and Goverdhannathji Foreword by Prof. Joel L. Sussman Receiving is not always important; however, giving back to society can be incredi- bly significant. This book, Introduction to Biomolecular Structure and Biophysics: Basics of Biophysics, is an excellent volume of Dr. Gauri Misra to present the fundamentals and advances in the field of Biophysics to the scientific community. A journey beginning from the basic macromolecular structure, their functioning, interactions transcending to the methodology that includes the classical and new approaches makes this effort incredibly worthwhile. Contribution from the experts in the field enhances the quality of the content. Reading about new folds and structures, e.g., the Roadblock and Longin folds, is fascinating and will clearly stimulate the reader from neophyte through expert. The book goes from classical biochemistry, e.g., amino acids, primary through quaternary structures, to very recent discoveries such as intrinsically disordered proteins. New discoveries and creative thought process keep the flame of scientific curiosity ignited. The magnitude of work done to bring forth the new advancements in the field makes the book unique. The principles of the most complex of techniques, e.g., the latest developments of cryoEM and their impact on structural biology, are explained in a very clear manner so that the student’s enthusiasm remains intact while reading. This book will be useful to people working not only in biophysics but also in other scientific disciplines from chemistry through life sciences. The text is strengthened enormously by beautiful diagrams. I strongly believe this book will be a reader’s delight providing comprehensive understanding of macromolecular structure and functioning. It will be an excellent introduction for students towards biophysics and will clearly help them to develop a wider perspective of the field. Department of Structural Biology Joel L. Sussman Weizmann Institute of Science Rehovot, Israel vii Foreword by Shekhar C. Mande I am pleased to write this foreword on the book edited by Dr. Gauri Misra. Having browsed through the book, I am very happy to note that the book addresses several important aspects of modern Biophysics. Dr. Misra herself is a well-trained biophysicist; therefore she is in a good position to edit such a book. The field of Biophysics has seen several important developments in recent years, such as the advent of cryo-electron microscopy for determining high-resolution structures of proteins and macromolecular assemblies, super-resolution microscopy for high-end imaging of biological systems, hydrogen deuterium exchange, etc. For the students, to keep up with these developments is difficult, unless guided by trained biophysicists in these areas. Dr. Misra has clearly attempted to do so by bringing together experts in different fields and writing chapters on these aspects. Moreover, the fundamentals of biophysics have been well covered so that students do not miss the basics while trying to understand the modern developments. This book also provides insights into different kinds of biomolecules, including polypeptides, nucleotides, membranes, lipids, etc., in sufficient details. The structural insights into functioning of various macromolecules are explained with the help of several illustrations. Moreover, many useful resources are included as part of chapters. This book covers areas, such as protein folding, higher-order nucleic acid structures, new protein folds, conformational aspects of proteins with functional implications, thermodynamics of protein/DNA stability, etc. Dr. Misra’s creative contribution as an author on the chapter on protein structure is worthy of appreciation. Thus, a good blend of fundamental biophysics, structural biology, and modern developments in biophysics has been achieved in this book. This book has attempted to provide basic understanding of simple and complex experimental and theoretical aspects of biophysics. I am therefore sure that students of biophysics at the under- graduate, postgraduate, and doctoral levels will find this book very useful. Director, National Centre for Cell Science Shekhar C. Mande Pune, India ix Preface The present book is the beginning of a new chapter in my academic journey. A successful accomplished research career ignited within me the desire to disseminate the knowledge to young students which are desirous of building a career in science. I joined the university structure and started teaching biophysics and structural biology to the undergraduate, postgraduate, and doctoral students. Interaction with the students introduced me to the reality that they have an inherent apprehen- sion for these subjects as the available resources for most of the underlying concepts in these subjects were either research articles or academic reviews. They expressed their desire to have a reference book which could encompass a compre- hensive collection of basic principles in biophysics and recent research developments in the concerned field. This was the driving force behind the concep- tion of this book. The last few decades have evidenced tremendous growth in the macromolecular data supported by advances in technology and methodology. This upsurge in the information about proteins, DNA, and lipid structure along with fundamentals of various classical and advanced biophysical techniques used in drug discovery process needs to reach out to students in a language that is elucidating and does draw extensively upon academic jargon. This underlying motive is being attempted at in the treatment of ideas, concepts, and experiences presented in this book. There are nine chapters that form the framework of this book. The idea to encompass knowledge spanning from what is known to what is unknown in the writings from the experts in the field resulted in a concerted effort to justify the various topics. We sincerely hope our efforts will be embraced by students with appreciation and enthusiasm for learning. Organization of the Book I would like to present an overview of ideas that inform the organization of this book. In doing this, I would also like to foreground the salient and novel features that might draw the attention of readers and make it interesting and engaging. The book is structured in nine chapters that bring to students interesting dimensions of human understanding that relate to the subject in focus. xi xii Preface The first chapter highlights the fundamentals of protein structure and functioning with emphasis on the role of various structural folds and motifs. The recent research findings involving a new fold have now enhanced our knowledge in the field. The newer discovery and some implications from this work have been incorporated. The second chapter elaborates the basic process of protein folding which is responsible for attributing them with the multitude of functions. An additional information on the computational understanding of this process including the various intermediates involved is being explained. The third chapter navigates through the basics of DNA and RNA structure with underlying structural principles and properties. A brief outline toward the various methods used for the identification of these structures is presented in the last section of this chapter. The fourth chapter extends the basic knowledge of nucleic acid structure to higher-order structures considering the latest developments in this domain that involves the exhaustive details of various higher-order structures, chemical principles in higher-order
Recommended publications
  • Specific Loop Modifications of the Thrombin Binding Aptamer Trigger the Formation of Parallel Structures
    “Specific loop modifications of the thrombin binding aptamer trigger the formation of parallel structures” Aviñó, A., Portella, G., Ferreira, R., Gargallo, R., Mazzini, S., Gabélica, V., Orozco, M., Eritja, R. The FEBS J., 281(4), 1085-1099 (2014). PMID: 24304855, doi: 10.1111/febs.12670 SPECIFIC LOOP MODIFICATIONS OF THE THROMBIN BINDING APTAMER TRIGGER THE FORMATION OF PARALLEL STRUCTURES Anna Aviñó1,#,Guillem Portella2,3,#, Ruben Ferreira1, Raimundo Gargallo5, Stefania Mazzini6, Valerie Gabélica7, Modesto Orozco,2,3,4*and Ramon Eritja1* 1Institute for Advanced Chemistry of Catalonia (IQAC), CSIC, Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Jordi Girona 18-26 08034 Barcelona, Spain. 2Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, 08028 Barcelona, Spain 3Joint IRB-BSC Program in Computational Biology, Barcelona, Spain 4Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, University of Barcelona, 08028 Barcelona, Spain 5Department of Analytical Chemistry, University of Barcelona, 08028 Barcelona, Spain 6Department of Food, Environmental and Nutritional Sciences (DEFENS), Section of Chemical and Biomolecular Sciences, University of Milan, Via Celoria 2, 20133 Milan, Italy 7Physical Chemistry and Mass Spectrometry Laboratory, Department of Chemistry, University of Liège, Belgium. (Present addresses: (1) Univ. Bordeaux, IECB - ARNA laboratory, F-33600 Pessac, France, (2) INSERM, U869 - ARNA laboratory, F-33000 Bordeaux, France. * To whom correspondence should
    [Show full text]
  • Extensive Evaluation of Force Fields for G-Quadruplexes
    Extensive Evaluation of Force Fields for G-Quadruplexes Na Li1, Tong Zhu1,2* 1Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, People’s Republic of China. 2NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, People’s Republic of China ABSTRACT G-Quadruplexes (GQs), folded by guanine-rich nucleic acid sequences, involve in gene expression processes and closely associated with the formation of tumors. So far, GQ has drawn widespread attention for its notable application of serving as potential anti-cancer target. Recently, theoretical studies for GQs have achieved significant progress, most of which are inseparable from molecular dynamics (MD) simulation. As a necessary tool to explore dynamics behavior of molecules, MD simulations strictly depend on force field parameters, which is a sticking point to obtain accurate results. Currently, many force fields for nucleic acids have been developed, but none of them have been accepted widely for GQs. In this paper, we selected five popular force fields, which are parmbsc0, parmbsc1, OL15, Drude2017 and AMOEBANUC17, and conducted explicit-solvent MD simulations on two DNA GQs respectively. We evaluated these force fields from many aspects in detail. Meanwhile, we compared conformational energy using quantum chemistry calculations. With the comprehensive evaluation, Drude2017 achieved better description for GQs, which we suggest that using Drude2017 force field should be taken into account first when investigating GQs by MD simulation. * To whom correspondence should be addressed. Email: [email protected]; [email protected] INTRODUCTION G-Quadruplexes (GQs)1 are folded by guanine-rich nucleic acid sequences.
    [Show full text]
  • Structure and Function of Multimeric G-Quadruplexes
    molecules Review Structure and Function of Multimeric G-Quadruplexes Sofia Kolesnikova 1,2 and Edward A. Curtis 1,* 1 The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, 166 10 Prague, Czech Republic 2 Department of Biochemistry and Microbiology, University of Chemistry and Technology, 166 28 Prague, Czech Republic * Correspondence: [email protected] Received: 13 August 2019; Accepted: 22 August 2019; Published: 24 August 2019 Abstract: G-quadruplexes are noncanonical nucleic acid structures formed from stacked guanine tetrads. They are frequently used as building blocks and functional elements in fields such as synthetic biology and also thought to play widespread biological roles. G-quadruplexes are often studied as monomers, but can also form a variety of higher-order structures. This increases the structural and functional diversity of G-quadruplexes, and recent evidence suggests that it could also be biologically important. In this review, we describe the types of multimeric topologies adopted by G-quadruplexes and highlight what is known about their sequence requirements. We also summarize the limited information available about potential biological roles of multimeric G-quadruplexes and suggest new approaches that could facilitate future studies of these structures. Keywords: G-quadruplex; dimer; tetramer; multimer; oligomer; telomere; promoter; R-loop; DNA:RNA hybrid 1. Introduction The B-form double helix is the most well known nucleic acid structure, but it is not the only one. Other examples include double helices with geometries that differ from that of classical B-form DNA, such as Z-DNA [1], triple helices [2], and even four-stranded structures in which canonical A-T and C-G base pairs are absent [3,4].
    [Show full text]
  • Thermodynamic Characterization of Tetraplex Dna Structures
    THERMODYNAMIC CHARACTERIZATION OF TETRAPLEX DNA STRUCTURES by BYUL KIM A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Department of Pharmaceutical Sciences Leslie Dan Faculty of Pharmacy University of Toronto © Copyright by Byul Kim 2018 ABSTRACT Thermodynamic Characterization of Tetraplex DNA Structures Byul Kim Doctor of Philosophy Department of Pharmaceutical Sciences Leslie Dan Faculty of Pharmacy University of Toronto 2018 The role of counterion condensation as a dominant force governing the stability of DNA duplexes and triplexes is well established. In contrast, the effect of counterion condensation on the stability of G-quadrupex conformations is poorly understood. Unlike other ordered nucleic acid structures, G-quadruplexes exhibit a specific binding of counterions (typically, Na+ or K+) which are buried inside the central cavity and coordinated to the O6 carbonyls of the guanines forming the G-quartets. While it has been known that the G-quadruplex-to-coil transition temperature, TM, increases with an increase in the concentration of the stabilizing ion, the contributions of the specific (coordination in the central cavity) and nonspecific (condensation) ion binding have not been resolved. In the first part of the work performed in this dissertation, we used G-quadruplexes formed by four different sequences derived from the human telomeric region, c-MYC, and VEGF genes to separate the two ionic contributions. We studied the change + + in TM of preformed G-quadruplexes following the addition of nonstabilizing ions Li , Cs , and TMA+ (tetramethylammonium). Our data suggest that the stabilizing action of cations on the G- quadruplex conformation is, primarily, due to the central ions which act as specifically bound II ligands.
    [Show full text]
  • DNA Sequences That Interfere with Transcription: Implications for Genome Function and Stability † ‡ † Boris P
    Review pubs.acs.org/CR DNA Sequences That Interfere with Transcription: Implications for Genome Function and Stability † ‡ † Boris P. Belotserkovskii, Sergei M. Mirkin, and Philip C. Hanawalt*, † Department of Biology, Stanford University, Stanford, California 94305, United States ‡ Department of Biology, Tufts University, Medford, Massachusetts 02155, United States 1. INTRODUCTION The primary role of DNA-dependent RNA synthesis, or transcription, is to create components for the cellular machinery. The nascent RNA product of transcription is released from the DNA template and either serves as an intermediate message for protein synthesis or is used directly, as in the case of rRNA, tRNA, and various types of regulatory RNAs. Recently, a growing number of examples suggest that transcription per se, rather than its released product, could play a regulatory role in gene function or as a trigger for genomic modifications. The latter scenario is commonly attributed to anomalous progression of the RNA polymerase (RNAP), such as pausing CONTENTS or termination and/or retaining rather than releasing the nascent transcript. This has been implicated in class-switch 1. Introduction 8620 recombination and somatic hypermutation (reviewed in refs 1, − 2. Transcription Blockage Mechanisms 8621 2), telomere maintenance,3 and replication initiation.4 9 3. Effects of Unusual DNA Structures and DNA/RNA Anomalous transcription elongation has also been linked to Complexes on Transcription 8622 various deleterious phenomena, such as genomic instabilities, 3.1. General Introduction to DNA Structure and transcription−replication collisions, and transcription defi- DNA Supercoiling 8622 ciency in some hereditary human disorders (reviewed in refs 3.2. Overview of Unusual Structures and Their 10−14).
    [Show full text]
  • Structure, Properties, and Biological Relevance of the DNA and RNA G Quadruplexes: Overview 50 Years After Their Discovery
    ISSN 00062979, Biochemistry (Moscow), 2016, Vol. 81, No. 13, pp. 16021649. © Pleiades Publishing, Ltd., 2016. Original Russian Text © N. G. Dolinnaya, A. M. Ogloblina, M. G. Yakubovskaya, 2016, published in Uspekhi Biologicheskoi Khimii, 2016, Vol. 56, pp. 53154. REVIEW Structure, Properties, and Biological Relevance of the DNA and RNA GQuadruplexes: Overview 50 Years after Their Discovery N. G. Dolinnaya1*, A. M. Ogloblina2, and M. G. Yakubovskaya2 1Lomonosov Moscow State University, Department of Chemistry, 119991 Moscow, Russia; Email: [email protected] 2Blokhin Cancer Research Center, Institute of Carcinogenesis, Russian Academy of Medical Sciences, 115478 Moscow, Russia Received June 15, 2016 Abstract—Gquadruplexes (G4s), which are known to have important roles in regulation of key biological processes in both normal and pathological cells, are the most actively studied noncanonical structures of nucleic acids. In this review, we summarize the results of studies published in recent years that change significantly scientific views on various aspects of our understanding of quadruplexes. Modern notions on the polymorphism of DNA quadruplexes, on factors affecting thermo dynamics and kinetics of G4 folding–unfolding, on structural organization of multiquadruplex systems, and on conforma tional features of RNA G4s and hybrid DNA–RNA G4s are discussed. Here we report the data on location of G4 sequence motifs in the genomes of eukaryotes, bacteria, and viruses, characterize G4specific smallmolecule ligands and proteins, as well as the mechanisms of their interactions with quadruplexes. New information on the structure and stability of G4s in telomeric DNA and oncogene promoters is discussed as well as proof being provided on the occurrence of Gquadruplexes in cells.
    [Show full text]
  • A Novel G-Quadruplex-Forming GGA Repeat Region in the C-Myb Promoter Is a Critical Regulator of Promoter Activity Sunmi L
    Published online 5 February 2008 Nucleic Acids Research, 2008, Vol. 36, No. 6 1755–1769 doi:10.1093/nar/gkm1069 A novel G-quadruplex-forming GGA repeat region in the c-myb promoter is a critical regulator of promoter activity SunMi L. Palumbo1, Regan M. Memmott1, Diana J. Uribe1, Yulia Krotova-Khan1, Laurence H. Hurley1,2,3 and Scot W. Ebbinghaus1,* 1Arizona Cancer Center, University of Arizona, 1515 N. Campbell Ave., Tucson, AZ 85724-5024, 2College of Pharmacy, University of Arizona, 1295 N. Martin Ave., Tucson, AZ 85721 and 3BIO5 Institute, University of Arizona, 1657 E. Helen St., Tucson, AZ 85721, USA Received May 31, 2007; Revised and Accepted November 13, 2007 ABSTRACT encodes a critical transcription factor for proliferation, differentiation and survival of haematopoietic progenitor The c-myb promoter contains multiple GGA repeats cells (1). High levels of the gene product c-Myb prevent beginning 17 bp downstream of the transcription haematopoietic stem cells from both differentiation and initiation site. GGA repeats have been previously apoptosis (2,3). Because of the critical role of c-Myb in shown to form unusual DNA structures in solution. determining cell fate, c-Myb expression levels are tightly Results from chemical footprinting, circular dichro- controlled in normal cells, showing high levels in ism and RNA and DNA polymerase arrest assays on immature, proliferating haematopoietic cells and unde- oligonucleotides representing the GGA repeat region tectable levels in differentiated cells (4). c-Myb is over of the c-myb promoter demonstrate that the element expressed in many leukemias and some solid tumors, and is able to form tetrad:heptad:heptad:tetrad (T:H:H:T) plays a critical role in leukemogenesis by maintaining cells G-quadruplex structures by stacking two tetrad:hep- in a proliferative state and by preventing terminal tad G-quadruplexes formed by two of the three differentiation (5–7).
    [Show full text]
  • Structural Studies on DNA G-Quadrupiexes
    October 2006 Structural studies on DNA G-quadrupIexes Sarah Wallace Burge {née Rankin) A thesis submitted for the degree of Doctor of Philosophy of the University of London Cancer Research UK Biomolecular Structure Group The School of Pharmacy University of London ProQuest Number: 10104293 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest. ProQuest 10104293 Published by ProQuest LLC(2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. Microform Edition © ProQuest LLC. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 Acknowledgements This work is in part a testament to the advice and encouragement I have received from various quarters over the past three years. They are too numerous to include and these brief mentions are somewhat inadequate to express my gratitude for their forbearance, wisdom and friendship. My supervisor, Professor Stephen Neidle, provided excellent direction and advice which resulted in a fulfilling and productive three years. I extend my thanks also to Dr Gary Parkinson for his advice and to Dr Mire Zloh for his assistance with NMR data collection at the School of Pharmacy. The hospitality of Dr Anh Tuan Phan and Professor Dinshaw Patel at the Memorial Sloan Kettering Cancer Center, New York, made for a truly memorable visit; I am indebted to them for their assistance in the synthesis of the '^N labelled DNA and collection of the associated NMR spectra.
    [Show full text]
  • Molecular Dynamics Simulations Reveal the Balance of Forces Governing the Formation of a Guanine Tetrad––A Common Structural
    3020–3030 Nucleic Acids Research, 2016, Vol. 44, No. 7 Published online 14 March 2016 doi: 10.1093/nar/gkw160 Molecular dynamics simulations reveal the balance of forces governing the formation of a guanine tetrad––a common structural unit of G-quadruplex DNA Mateusz Kogut, Cyprian Kleist and Jacek Czub* Department of Physical Chemistry, Gdansk University of Technology, ul. Narutowicza 11/12, 80-233 Gdansk, Poland Received January 20, 2016; Revised February 26, 2016; Accepted March 1, 2016 ABSTRACT mation of G4 motifs at the single-stranded telomeric 3- overhang leads to telomerase inhibition (10) and competes G-quadruplexes (G4) are nucleic acid conformations with the binding of the ssDNA overhang by POT1, a com- of guanine-rich sequences, in which guanines are ponent of shelterin protein complex protecting chromoso- arranged in the square-planar G-tetrads, stacked on mal ends (11–13). Accordingly, G4-stabilizing agents, such one another. G4 motifs form in vivo and are impli- as telomestatin, have been shown to impair telomere home- cated in regulation of such processes as gene ex- ostasis and thereby to induce growth arrest or apoptosis in pression and chromosome maintenance. The struc- cultured cells (14–16). As a result, G4 DNA is now consid- ture and stability of various G4 topologies were de- ered a promising target for anticancer therapy (17–19). G4- termined experimentally; however, the driving forces forming sequences are also found to be over-represented in for their formation are not fully understood at the other regulatory regions of the genome, including promot- molecular level. Here, we used all-atom molecular ers (20,21), introns (22), mitotic and meiotic double-strand break sites (6), immunoglobulin switch regions (9) and 5- dynamics to probe the microscopic origin of the G4 UTRs (23).
    [Show full text]
  • Possible Regulatory Roles of Promoter G-Quadruplexes in Cardiac Function-Related Genes – Human Tnic As a Model
    Possible Regulatory Roles of Promoter G-Quadruplexes in Cardiac Function-Related Genes – Human TnIc as a Model Wenhua Zhou1, Kogularamanan Suntharalingam2, Nigel J. Brand3, Paul J. R. Barton3,4, Ramon Vilar2, Liming Ying1* 1 Molecular Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom, 2 Department of Chemistry, Imperial College London, London, United Kingdom, 3 Harefield Heart Science Centre, National Heart and Lung Institute, Imperial College London, Middlesex, United Kingdom, 4 NIHR Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Trust, London, United Kingdom Abstract G-quadruplexes (G4s) are four-stranded DNA secondary structures, which are involved in a diverse range of biological processes. Although the anti-cancer potential of G4s in oncogene promoters has been thoroughly investigated, the functions of promoter G4s in non-cancer-related genes are not well understood. We have explored the possible regulatory roles of promoter G4s in cardiac function-related genes using both computational and a wide range of experimental approaches. According to our bioinformatics results, it was found that potential G4-forming sequences are particularly enriched in the transcription regulatory regions (TRRs) of cardiac function-related genes. Subsequently, the promoter of human cardiac troponin I (TnIc) was chosen as a model, and G4s found in this region were subjected to biophysical characterisations. The chromosome 19 specific minisatellite G4 sequence (MNSG4) and near transcription start site (TSS) G4 sequence (280 G4) adopt anti-parallel and parallel structures respectively in 100 mM KCl, with stabilities comparable to those of oncogene G4s. It was also found that TnIc G4s act cooperatively as enhancers in gene expression regulation in HEK293 cells, when stabilised by a synthetic G4-binding ligand.
    [Show full text]
  • Genomic Deoxyuracil: Targeting, Regulation and Repair
    Illinois State University ISU ReD: Research and eData Theses and Dissertations 9-25-2015 Genomic Deoxyuracil: Targeting, Regulation And Repair Nate Warren Holton Illinois State University, [email protected] Follow this and additional works at: https://ir.library.illinoisstate.edu/etd Part of the Molecular Biology Commons Recommended Citation Holton, Nate Warren, "Genomic Deoxyuracil: Targeting, Regulation And Repair" (2015). Theses and Dissertations. 468. https://ir.library.illinoisstate.edu/etd/468 This Dissertation is brought to you for free and open access by ISU ReD: Research and eData. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of ISU ReD: Research and eData. For more information, please contact [email protected]. GENOMIC DEOXYURACIL: TARGETING, REGULATION AND REPAIR Nate W. Holton 127 pages Maintaining genomic integrity is critical to avoid sequence mutations and genetic disease. However the immune system requires genomic rearrangements in order to produce novel antibodies and elicit a full immunological response. The expression of DNA modifying enzymes is essential for antibody production but the off target effects are not well understood. The work presented here was performed to elucidate molecular mechanisms responsible for the regulation and targeting of DNA editing enzymes, as well as characterize repair of these lesions at off target loci. KEYWORDS: Activation Induced Cytosine Deaminase, AID, miRNA, miR155, miR93, G-quadruplex, G4, Uracil DNA Glycosylase, UDG, UNG GENOMIC DEOXYURACIL: TARGETING, REGULATION AND REPAIR NATE W. HOLTON A Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY School of Biological Sciences ILLINOIS STATE UNIVERSITY 2015 Copyright 2015 Nate W.
    [Show full text]
  • Guanine Quadruplexes and Disease: Insight Into Mechanisms and Therapeutic Potential
    Guanine quadruplexes and disease: Insight into mechanisms and therapeutic potential Katie Manas and Celena Hoeve Abstract Understanding Guanine Quadruplexes (G4s) provides valuable insight into a wide array of diseases at a genetic level and their potential therapy. These unusual architectures can form in DNA and RNA, composed of planar, stacked tetrads of four hydrogen bonded guanines. G4s are widely implicated in a range of disease categories, including parasites, viral infections, cancer, and neurodegenerative diseases, with varied roles within each. Of current relevance, a connection to the coronavirus family may be an intriguing avenue of investigation for recent outbreaks. The planar surface of the G4 tetrad also provides an attractive target for small molecule binders that can provide therapeutic value. Overall, this review aims to address the exciting relevance of G4s in these felds, a few major mechanisms of action, and their potential as therapeutic targets. 1. Introduction arise from the orientation of the four guanine segments with Though most are familiar with DNA as a double stranded respect to the 3’ and 5’ ends. Parallel G4s have all strands helical structure composed of four nucleobases (ACTG), it oriented in the same direction, while antiparallel G4s have also has the ability to form other higher-order architectures, the four strands in alternating directions. Hybrid G4s have such as the well-known guanine quadruplex (G4). G4s were three strands oriented in one direction and the fourth strand frst proposed in 1962 (Gellert et al. 1962), as three-dimen- in the other direction. G4s can also be described based on sional architectures that form in guanine-rich environments.
    [Show full text]