Many cellular processes occur out of equilibrium. This includes site-specific unwinding in supercoiled DNA, which may play an important role in gene regulation. Here, we use the Convex Lens-induced Confinement (CLiC) single-molecule microscopy platform to study these processes with high-throughput and without artificial constraints on molecular structures or interactions. We use two model DNA plasmid systems, pFLIP-FUSE and pUC19, to study the dynamics of supercoiling-induced secondary structural transitions after perturbations away from equilibrium. We find that structural transitions can be slow, leading to long-lived structural states whose kinetics depend on the duration and direction of perturbation. Our findings highlight the importance of out-of-equilibrium studies when characterizing the complex structural dynamics of DNA and understanding the mechanisms of gene regulation.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8934633 | PMC |
http://dx.doi.org/10.1093/nar/gkac101 | DOI Listing |
Nat Commun
January 2025
Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
Tetrahydrocannabinol (THC) is the principal psychoactive compound derived from the cannabis plant Cannabis sativa and approved for emetic conditions, appetite stimulation and sleep apnea relief. THC's psychoactive actions are mediated primarily by the cannabinoid receptor CB. Here, we determine the cryo-EM structure of HU210, a THC analog and widely used tool compound, bound to CB and its primary transducer, G.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Advanced Analysis Data Center, Korea Institute of Science and Technology, Hwarang-ro 14-5, Seongbuk-gu, Seoul 02792, Republic of Korea.
Riboswitches are RNAs that recognize ligands and regulate gene expression. They are typically located in the untranslated region of bacterial messenger RNA and consist of an aptamer and an expression platform. In this study, we examine the folding pathway of the Vc2 (Vibrio cholerae) riboswitch aptamer domain, which targets the bacterial secondary messenger cyclic-di-GMP.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Chemistry Department, Lomonosov Moscow State University, Moscow 119991, Russia.
Non-canonical nucleic acid structures play significant roles in cellular processes through selective interactions with proteins. While both natural and artificial G-quadruplexes have been extensively studied, the functions of i-motifs remain less understood. This study investigates the artificial aptamer BV42, which binds strongly to influenza A virus hemagglutinin and unexpectedly retains its i-motif structure even at neutral pH.
View Article and Find Full Text PDFNat Mater
January 2025
Department of Fundamental Engineering, Institute of Industrial Science, The University of Tokyo, Tokyo, Japan.
Supercooled liquids display sluggish dynamics, often attributed to their structural characteristics, yet the underlying mechanism remains elusive. Here we conduct numerical investigations into the structure-dynamics relationship in model glass-forming liquids, with a specific focus on an elementary particle rearrangement mode known as the 'T1 process'. We discover that the ability of a T1 process to preserve glassy structural order before and after is pivotal towards determining a liquid's fragility-whether it exhibits super-Arrhenius-like or Arrhenius-like behaviour.
View Article and Find Full Text PDFMol Biotechnol
January 2025
Amity Institute of Biotechnology, Amity University, Kolkata, India.
Nine homologous Cold Shock Proteins (Csps) have been recognized in the E.coli Cold Shock Domain gene family. These Csps function as RNA chaperones.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!