Biomaterial Database

Non-equilibrium structural dynamics of supercoiled DNA plasmids exhibits asymmetrical relaxation. 2022

Cynthia Shaheen, and Cameron Hastie, and Kimberly Metera, and Shane Scott, and Zhi Zhang, and Sitong Chen, and Gracia Gu, and Lisa Weber, and Brian Munsky, and Fedor Kouzine, and David Levens, and Craig Benham, and Sabrina Leslie

Department of Physics, McGill University, Montreal, QC H3A 2T8, Canada.

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.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D009690	Nucleic Acid Conformation	The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.	DNA Conformation,RNA Conformation,Conformation, DNA,Conformation, Nucleic Acid,Conformation, RNA,Conformations, DNA,Conformations, Nucleic Acid,Conformations, RNA,DNA Conformations,Nucleic Acid Conformations,RNA Conformations
D010957	Plasmids	Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.	Episomes,Episome,Plasmid
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004278	DNA, Superhelical	Circular duplex DNA isolated from viruses, bacteria and mitochondria in supercoiled or supertwisted form. This superhelical DNA is endowed with free energy. During transcription, the magnitude of RNA initiation is proportional to the DNA superhelicity.	DNA, Supercoiled,DNA, Supertwisted,Supercoiled DNA,Superhelical DNA,Supertwisted DNA
D000072760	Single Molecule Imaging	High resolution imaging techniques that allow visualization of individual molecules of proteins, lipids, or nucleic acids within cells or tissues.	Single Molecule Analysis,Single Molecule Tracking,Single Particle Analysis,Single Particle Imaging,Single Particle Microscopy,Single Particle Spectroscopy,Single Particle Tracking,Single Molecule Microscopy,Single Molecule Spectroscopy,Analyses, Single Particle,Analysis, Single Molecule,Analysis, Single Particle,Imaging, Single Molecule,Imaging, Single Particle,Microscopies, Single Particle,Microscopy, Single Molecule,Microscopy, Single Particle,Particle Tracking, Single,Single Molecule Analyses,Single Particle Analyses,Single Particle Microscopies,Single Particle Spectroscopies,Single Particle Trackings,Spectroscopy, Single Molecule,Spectroscopy, Single Particle,Tracking, Single Molecule,Tracking, Single Particle