Publications related to Tightening of DNA knots by supercoiling facilitates their unknotting by type II DNA topoisomerases

Chromosome organization shapes replisome dynamics in Caulobacter crescentus

Suliana Manley, Laurent Casini, Chen Zhang

DNA replication in bacteria takes place on highly compacted chromosomes, where segregation, transcription, and repair must occur simultaneously. Within this dynamic environment, colocalization of sister replisomes has been observed in many bacterial specie ...

Nature Portfolio2024

Oxidative Defect Detection Within Free and Packed DNA Systems: A Quantum Mechanical/Molecular Mechanics (QM/ MM) Approach

Ursula Röthlisberger

Base excision repair enzymes (BERs) detect and repair oxidative DNA damage with efficacy despite the small size of the defects and their often only minor structural impact. A charge transfer (CT) model for rapid scanning of DNA stretches has been evoked to ...

Swiss Chemical Soc2024

A chemical biology approach to decipher chromatin ubiquitylation by RNF168

Pauline Franz

DNA damage signaling following DNA double-strand breaks (DSBs) involves numerous regulating proteins, which dynamically recognize ('read') and alter ('write' or 'erase') histone post-translational modifications (PTMs). Among these PTMs, the ubiquitin syste ...

EPFL2024

Resolving bacterial cell biology: from replisome dynamics to cell wall synthesis

Chen Zhang

Bacteria are ubiquitous single cellular organisms. Compared to eukaryotic cells, bacteria have two unique characteristics: the membrane-less nucleoid and the cell wall built of peptidoglycan (PG). In most bacteria, a single circular chromosome is compacted ...

EPFL2024

Mechanics of Physical Knots: From Filaments in Contact to Surgical Suturing

Paul Johanns

In this thesis, we study the mechanics of tight physical knots. Knots are omnipresent in surgery, climbing, and sailing, with disastrous consequences when the filament or the rope fails to perform its function. Even if the importance of mechanical analysis ...

EPFL2023

Telomere protection against oxidative stress

Thu Trang Nguyen

Telomeres are nucleoprotein structures at the ends of linear chromosomes, being essential for the maintenance of genomic integrity. Telomeres have a unique structure which distinguishes chromosome termini from DNA damage sites. Shelterin complexes are the ...

EPFL2023

Landscapes of DNA Mechanics and Genomes

Thomas Antonin Zwahlen

The local physical properties - such as shape and flexibility - of the DNA double-helix is today widely believed to be influenced by nucleic acid sequence in a non-trivial way. Furthermore, there is strong evidence that these properties play a role in many ...

EPFL2023

Development of multiplexed single-molecule imaging techniques to study chromatin invasion dynamics of chromatin effector proteins

Kristina Makasheva

DNA-binding proteins physically interact with the DNA and directly affect genomic functions. The eukaryotic genome is compacted into chromatin, limiting the DNA access to nuclear factors. In this Ph.D. thesis, I explored the dynamic mechanisms, that allow ...

EPFL2023

Computational Exploration of Multistable Elastic Knots

Mark Pauly, Michele Vidulis, Yingying Ren

We present an algorithmic approach to discover, study, and design multistable elastic knots. Elastic knots are physical realizations of closed curves embedded in 3-space. When endowed with the material thickness and bending resistance of a physical wire, t ...

2023

cgNA+: A sequence-dependent coarse-grain model of double-stranded nucleic acids

Rahul Sharma

DNA mechanics plays a crucial role in many biological processes, including nucleosome positioning and protein-DNA interactions. It is believed that nature employs epigenetic modifications in DNA to further regulate gene expression. Moreover, double-strande ...

EPFL2023

A field-capable rapid plant DNA extraction protocol using microneedle patches for botanical surveying and monitoring

Sebastian Maerkl, Jonathan Selz, Nicolas Rémi Adam

PremiseA novel protocol for rapid plant DNA extraction using microneedles is proposed, which supports botanic surveys, taxonomy, and systematics. This protocol can be conducted in the field with limited laboratory skills and equipment. The protocol is vali ...

WILEY2023

C2CAplus: A One-Pot Isothermal Circle-to-Circle DNA Amplification System

Sebastian Maerkl, Laura Sophie Grasemann

Rolling circle amplification (RCA) is a widely used DNA amplification method that uses circular template DNA as input and produces multimeric, linear single- or double-stranded DNA. Circle-to-circle amplification (C2CA) has further expanded this method by ...

Amer Chemical Soc2023

Achieving high hybridization density at DNA biosensor surfaces using branched spacer and click chemistry

Mounir Driss Mensi, Sandrine Gerber, Lucas Mayoraz, Perrine Agnes Edith Robin, Alireza Kavand

The COVID-19 pandemic has highlighted the necessity to develop fast, highly sensitive and selective virus detection methods. Surface-based DNA-biosensors are interesting candidates for this purpose. Functionalization of solid substrates with DNA must be pr ...

2023

Regulation and impact of TERRA R-loops at human telomeres

Rita Valador Fernandes

Telomeres are the nucleoprotein structures found at the ends of linear chromosomes. They ensure that the termini of chromosomes are not inappropriately recognized as sites of DNA damage, and are therefore crucial for genome stability. In spite of the heter ...

EPFL2023

cgNA plus web : A Visual Interface to the cgNA plus Sequence-dependent Statistical Mechanics Model of Double-stranded Nucleic Acids

John Maddocks, Alessandro Samuele Patelli, Lennart de Bruin, Rahul Sharma

The sequence-dependent statistical mechanics of double-stranded nucleic acid, or dsNA, is believed to be essential in its biological functions. In turn, the equilibrium statistical mechanics behaviour of dsNA depends strongly both on sequence-dependent per ...

Elsevier2023

Secondary structure of the human mitochondrial genome affects formation of deletions

Jacques Fellay, Konstantin Popadin

BackgroundAging in postmitotic tissues is associated with clonal expansion of somatic mitochondrial deletions, the origin of which is not well understood. Such deletions are often flanked by direct nucleotide repeats, but this alone does not fully explain ...

BMC2023

Recycling of Polymerase Chain Reaction (PCR) Kits

Francesco Stellacci, Yong Zhu, Weina Liu

Polymerase chain reaction (PCR) kits have been used as common diagnosing tools during the outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, with daily worldwide usage in the millions. It is well known that at the beginn ...

AMER CHEMICAL SOC2023

Interplay of the mechanical and structural properties of DNA nanostructures determines their electrostatic interactions with lipid membranes

Maartje Martina Cornelia Bastings, Cem Tekin, Vincenzo Caroprese, Diana Kornelia Morzy

Nucleic acids and lipids function in close proximity in biological processes, as well as in nanoengineered constructs for therapeutic applications. As both molecules carry a rich charge profile, and frequently coexist in complex ionic solutions, the electr ...

ROYAL SOC CHEMISTRY2023

Polydimethylsiloxane microstructure-induced acoustic streaming for enhanced ultrasonic DNA fragmentation on a microfluidic chip

Thomas Lehnert, Martinus Gijs, Lin Sun

Next-generation sequencing (NGS) is an essential technology for DNA identification in genomic research. DNA fragmentation is a critical step for NGS and doing this on-chip is of great interest for future integrated genomic solutions. Here we demonstrate fa ...

ROYAL SOC CHEMISTRY2022

Exploring the inner workings of the clove hitch knot

Paul Grandgeorge, Pedro Miguel Nunes Pereira de Almeida Reis, Paul Johanns, Tomohiko Sano, Changyeob Baek

We perform a combined experimental and computational investigation of the clove hitch knot. We develop a physical model for the clove hitch by tying an elastic rod onto a rigid cylinder. In the experiments, we characterize the mechanical performance, geome ...

ELSEVIER2022