A5023204894- DNA and Nucleic Acid Chemistry
- Advanced biosensing and bioanalysis techniques
- Force Microscopy Techniques and Applications
- RNA and protein synthesis mechanisms
- DNA Repair Mechanisms
- Genomics and Chromatin Dynamics
- Bacterial Genetics and Biotechnology
- Molecular Junctions and Nanostructures
- Bacteriophages and microbial interactions
- Cancer therapeutics and mechanisms
- Mechanical and Optical Resonators
- RNA Interference and Gene Delivery
- Nanopore and Nanochannel Transport Studies
- RNA Research and Splicing
- RNA modifications and cancer
- Advanced Electron Microscopy Techniques and Applications
- Nanofabrication and Lithography Techniques
- Advanced Fluorescence Microscopy Techniques
- Microfluidic and Capillary Electrophoresis Applications
- CRISPR and Genetic Engineering
- Microfluidic and Bio-sensing Technologies
- Cancer-related molecular mechanisms research
- Monoclonal and Polyclonal Antibodies Research
- Protein Structure and Dynamics
- SARS-CoV-2 and COVID-19 Research
Centre National de la Recherche Scientifique
2014-2024
La Ligue Contre le Cancer
2016-2024
Institut de Biologie de l'École Normale Supérieure
2016-2024
École Normale Supérieure - PSL
2000-2024
Inserm
2016-2024
Université Paris Sciences et Lettres
2016-2024
Institut Jacques Monod
2013-2022
Université Paris Cité
2013-2022
Centre de Gestion Scientifique
2022
Laboratoire de Géologie de l’École Normale Supérieure
2021
Single linear DNA molecules were bound at multiple sites one extremity to a treated glass cover slip and the other magnetic bead. The was therefore torsionally constrained. A field used rotate beads thus coil pull DNA. stretching force determined by analysis of Brownian fluctuations Here elastic behavior individual lambda over- underwound up 500 turns studied. sharp transition discovered from low high extension state approximately 0.45 piconewtons for 3 overwound ones. These transitions,...
Using single-molecule DNA nanomanipulation, we show that abortive initiation involves "scrunching"--in which RNA polymerase (RNAP) remains stationary and unwinds pulls downstream into itself--and scrunching requires synthesis depends on length. We further promoter escape scrunching, occurs in most or all instances of escape. Our results support the existence an obligatory stressed intermediate, with approximately one turn additional unwinding, are consistent proposal stress this intermediate...
In this paper we review the biophysics revealed by stretching single biopolymers. During last decade various techniques have emerged allowing micromanipulation of molecules and simultaneous measurements their elasticity. Using such techniques, it has been possible to investigate some interactions playing a role in biology. We shall first simplest case non-interacting polymer then present structural transitions DNA, RNA proteins that studied single-molecule techniques. explain how these...
Nancy J. Crisona1, Terence R. Strick2, David Bensimon2, Vincent Croquette2, and Nicholas Cozzarelli1,3 Department of Molecular Cell Biology, University California, Berkeley, California 94720, USA; 2Laboratoire de Physique Statistique l'ENS, associé aux universités Paris VI et VII, 75231 Cedex 05, France
By monitoring the end-to-end extension of a mechanically stretched, supercoiled, single DNA molecule, we have been able directly to observe change in associated with unwinding approximately one turn promoter by RNA polymerase (RNAP). performing parallel experiments negatively and positively supercoiled DNA, deconvolute caused RNAP-dependent (with ≈1-bp resolution) compaction ≈5-nm resolution). We used this approach quantify extent compaction, kinetics effects supercoiling, sequence, ppGpp,...
By using elastic measurements on single DNA molecules, we show that stretching a negatively supercoiled activates homologous pairing in physiological conditions. These experiments indicate stretched unwound locally denatures to alleviate the force-driven increase torsional stress. This is detected by hybridization with 1 kb of single-stranded probes. The force involved (≈2 pN) small compared those typically developed molecular motors, suggesting this process may be relevant processing vivo ....
Significance Transcription initiation by RNA polymerase (RNAP) is a highly regulated rate-limiting step in many genes and involves numerous intermediate states that remain incompletely understood. Here, we report the characterization of previously hypothesized slow pathway involving RNAP backtracking pausing. This backtracked paused state observed when all nucleoside triphosphates (NTPs) are present at physiologically relevant concentrations, but becomes more prevalent with unbalanced NTP...
Mechanistic studies in DNA repair have focused on roles of multi-protein complexes, so how long non-coding RNAs (lncRNAs) regulate is less well understood. Yet, lncRNA LINP1 over-expressed multiple cancers and confers resistance to ionizing radiation chemotherapeutic drugs. Here, we unveil structural mechanistic insights into LINP1's ability facilitate non-homologous end joining (NHEJ). We characterized structure flexibility analyzed interactions with the NHEJ factor Ku70/Ku80 (Ku) Ku...
Abstract Sen1 is an essential helicase for factor-dependent transcription termination in Saccharomyces cerevisiae, whose molecular-motor mechanism has not been well addressed. Here, we use single-molecule experimentation to better understand the determinants of its action on RNA polymerase II (Pol II) complex. We quantify translocation activity single-stranded DNA (ssDNA), finding elevated rates, high levels processivity and ATP affinities. Upon deleting N- C-terminal domains, or further...
Abstract Factor-dependent termination uses molecular motors to remodel transcription machineries, but the associated mechanisms, especially in eukaryotes, are poorly understood. Here we use single-molecule fluorescence assays characterize real time composition and catalytic states of Saccharomyces cerevisiae complexes remodeled by Sen1 helicase. We confirm that takes RNA transcript as its substrate translocates along it hydrolyzing multiple ATPs form an intermediate with a stalled polymerase...