A5007295683- DNA and Nucleic Acid Chemistry
- Advanced biosensing and bioanalysis techniques
- RNA Interference and Gene Delivery
- RNA and protein synthesis mechanisms
- Bacteriophages and microbial interactions
- RNA Research and Splicing
- RNA modifications and cancer
- Viral Infections and Immunology Research
- Molecular Junctions and Nanostructures
- Genomics and Chromatin Dynamics
- Genetics, Aging, and Longevity in Model Organisms
- X-ray Diffraction in Crystallography
- Viral gastroenteritis research and epidemiology
- DNA and Biological Computing
- Metal complexes synthesis and properties
- Origins and Evolution of Life
- Electrospun Nanofibers in Biomedical Applications
- Fungal and yeast genetics research
- Genetic Neurodegenerative Diseases
- Animal Virus Infections Studies
- Hepatitis C virus research
- Mechanical Engineering and Vibrations Research
- Crystallization and Solubility Studies
- Tissue Engineering and Regenerative Medicine
- HIV/AIDS drug development and treatment
Inserm
2014-2023
Institut Européen de Chimie et Biologie
2014-2023
Université de Bordeaux
2014-2023
Centre National de la Recherche Scientifique
2008-2023
Régulations Naturelle et Artificielle
2013-2022
Canadian Nautical Research Society
2018-2019
École Nationale Supérieure de Chimie, de Biologie et de Physique
2018
Nanyang Technological University
2008-2012
Memorial Sloan Kettering Cancer Center
2009
Université Paris Cité
2009
Previously, it has been reported that human telomeric DNA sequences could adopt in different experimental conditions four intramolecular G-quadruplexes each involving three G-tetrad layers, namely, Na+ solution antiparallel-stranded basket form, K+ crystal parallel-stranded propeller (3 + 1) Form 1, and 2. Here we present a new G-quadruplex adopted by four-repeat sequence (Form 3). This structure is basket-type with only two layers: loops are successively edgewise, diagonal, edgewise;...
Parallel tetramolecular quadruplexes may be formed with short oligodeoxynucleotides bearing a block of three or more guanines. We analyze the properties sequence variants parallel in which each guanine central was systematically substituted different base. Twelve types substitutions were assessed than 100 sequences. conducted comparative kinetic analysis all tetramers. Electrospray mass spectrometry used to count number inner cations, is an indicator effective tetrads. In general, presence...
Nucleic acid sequences containing guanine tracts are able to adopt noncanonical four-stranded nucleic structures called G-quadruplexes (G4s). These based on the stacking of two or more G-tetrads; each tetrad is a planar association four guanines held together by eight hydrogen bonds. In this study, we analyzed conserved G-rich region from HIV-1 promoter that known regulate transcription provirus. Strikingly, our analysis an alignment 1684 showed high conservation ability form G4 despite...
Quadruplex (G4) nucleic acids, a family of secondary structures formed by guanine-rich sequences, exhibit an important structural polymorphism. We demonstrate here that G-rich DNA sequences may function as double switch based on different triggers, provided their quadruplex and stability display high dependence cation nature concentration. A first is remarkable antiparallel-to-parallel conversion, taking place in few seconds at room temperature addition low KCl amounts to sodium-rich sample....
CEB25 is a human minisatellite locus, composed of slightly polymorphic 52-nucleotide (nt) tandem repeats. Genetically, most if not all individuals the population are heterozygous, carrying alleles ranging from 0.5 to 20 kb, maintained by mendelian inheritance but also subject germline instability. To provide insights on biological role CEB25, we interrogated its structural features. We report NMR structure G-quadruplex formed conserved 26-nt G-rich fragment motif. In K+ solution, this...
Abstract Recent studies indicate that i‐DNA, a four‐stranded cytosine‐rich DNA also known as the i‐motif, is actually formed in vivo; however, systematic study on sequence effects stability has been missing. Herein, an unprecedented number of different sequences (271) bearing four runs 3–6 cytosines with spacer lengths tested. While i‐DNA nearly independent total length, central plays special role stability. Stability depends length C‐tracts at both acidic and neutral pHs. This provides...
Peaceful coexistence: A double quadruplex composed of an i-motif and a G-quadruplex was constructed within one oligonucleotide strand (see picture). The defined double-quadruplex structure can serve as NOTIF logic gate on the basis fluorescence crystal violet.
DOTASQ (for DOTA-templated Synthetic G-quartet) is the first prototype of nature-inspired G-quadruplex ligand: its design, founded on a possible intramolecular G-quartet formation, enables it to interact with DNA via an unprecedented nature-mimicking binding mode, based association between two G-quartets, one being native (quadruplex) and other artificial (ligand).
DNA and RNA guanine-rich oligonucleotides can form non-canonical structures called G-quadruplexes or "G4" that are based on the stacking of G-quartets. The role G4 is documented in eukaryotic cells pathogens such as viruses. Yet, have been identified only a few viruses, including Flaviviridae family. In this study, we analysed last 157 nucleotides at 3'end HCV (-) strand. This sequence known to be minimal required for an efficient replication. Using bioinformatics biophysics, highly...
Abstract Genomic sequences susceptible to form G-quadruplexes (G4s) are always flanked by other nucleotides, but G4 formation in vitro is generally studied with short synthetic DNA or RNA oligonucleotides, for which bases adjacent the core often omitted. Herein, we systematically effects of flanking nucleotides on structural polymorphism 371 different oligodeoxynucleotides that adopt intramolecular structures. We found out addition favors a parallel fold, defined as ‘flanking effect’ this...
Recently, the human telomeric d[TAGGG(TTAGGG)3] sequence has been shown to form in K+ solution an intramolecular (3+1) G-quadruplex structure, whose G-tetrad core contains three strands oriented one direction and fourth opposite direction. Here we present a study on structure of Bombyx mori d[TAGG(TTAGG)3] sequence, which differs from counterpart only by G deletion each repeat. We found that this adopted multiple structures solution. have favored major judicious U-for-T substitution...
DNA and RNA guanine-quadruplexes (G4s) are stabilized by several cations, in particular potassium sodium ions. Generally, stabilizes guanine-quartet assemblies to a larger extent than sodium; this article we report about higher-order G4 structure more stable potassium. Repeats of the GGGTTA telomeric motif fold into contiguous units. Using three independent approaches (thermal denaturation experiments, isothermal molecular-beacon protein-binding assays), show that (GGGTTA)7GGG sequence,...
G-quadruplexes (G4s) are four-stranded nucleic acid structures formed by the stacking of G-tetrads. Here we investigated their formation and function during HIV-1 infection. Using bioinformatics biophysics analyses first searched for evolutionary conserved G4-forming sequences in genome. We identified 10 G4s with conservation rates higher than those regulatory such as RRE TAR. then used porphyrin-based G4-binders to probe infection human cells native HIV-1. The efficiently inhibited...
To understand the role of ribose G-quartets and how they affect properties G-quadruplex structures, we studied three systems in which one, two, three, or four deoxyribose were substituted with G-quartets. These a parallel DNA intramolecular G-quadruplex, d(TTGGGTGGGTTGGGTGGGTT), two tetramolecular G-quadruplexes, d(TGGGT) d(TGGGGT). Thermal denaturation experiments revealed that have position-dependent cumulative effects on stability. An unexpected destabilization was observed when rG...
Trinucleotide repeats are involved in a number of debilitating diseases such as myotonic dystrophy. Twelve to seventy-five base-long (CTG)n oligodeoxynucleotides were analysed using combination biophysical [UV-absorbance, circular dichroism and differential scanning calorimetry (DSC)] biochemical methods (non-denaturing gel electrophoresis enzymatic footprinting). All oligomers formed stable intramolecular structures under near physiological conditions with melting temperature that was only...
The Caenorhabditis elegans model has greatly contributed to the understanding of role G-quadruplexes in genomic instability. GGCTTA repeats C. telomeres resemble GGGTTA human telomeres. However, comparison telomeric sequences (Homo sapiens, Tetrahymena, Oxytricha, Bombyx mori and Giardia) revealed that small changes these can drastically change topology folded G-quadruplex. In present work we determined structure adopted by sequence d[GG(CTTAGG)3]. investigated is shown fold into an...
The T–Hg–T bond was utilized to cross-link two lateral loops of chair-type G-quadruplex DNA (G4-DNA) structures. Two out five cross-linking geometries are able increase the melting temperature and simultaneously reduce polymorphism G4-DNA conformations.
Friedliche Koexistenz: Ein doppelter Quadruplex aus einem i-Motiv und G-Quadruplex wurde innerhalb eines einzelnen Oligonucleotidstrangs aufgebaut (siehe Bild). Die definierte doppelte Quadruplexstruktur kann als ein NOTIF-Logikgatter auf der Basis Fluoreszenz von Kristallviolett genutzt werden. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed may be re-organized for online delivery, but not...