1.6: DNA Supercoiling and Topoisomerases - Biology LibreTexts
The DNA can coil up into a "supercoil" topology and maintain the desired twist value (10.6) with the given linking number (475 in this case). The duplex can exist with a twist of 10.6 bp/turn for most of the structure, and then have a region with zero twist (not necessarily a melted duplex).
DNA supercoil - Wikipedia
DNA supercoiling refers to the amount of twist in a particular DNA strand, which determines the amount of strain on it. A given strand may be "positively supercoiled" or "negatively supercoiled" (more or less tightly wound).
(PDF) Supercoiled DNA: Structure - ResearchGate
2001年9月21日 · DNA inside cells contains supercoils of two types: interwound supercoiling occurs when circular DNA winds around its own axis and toroidal supercoiling occurs when the DNA helix forms a...
Supercoiled Plasmid DNA on Agarose Gel: Secret of 3 Bands
2024年8月1日 · You can identify the linear DNA form on an agarose gel by comparing uncut plasmid DNA with a sample of the plasmid that has been linearized using a restriction enzyme. If you get linear DNA when you are hoping for supercoiled (e.g. after DNA plasmid preps), it is due to nuclease contamination or harsh treatment during purification.
Pictures of DNA and DNA supercoiling and their topological ...
Download scientific diagram | Pictures of DNA and DNA supercoiling and their topological representation from publication: On the heuristic power of mathematical representations | I argue...
The importance of being supercoiled: how DNA mechanics …
Positive DNA supercoiling promotes unwrapping of DNA from the histones and modifies nucleosome structure in vitro; in contrast nucleosomes rapidly form on negatively supercoiled DNA . Consequently, it was suggested that at each round of transcription, the positive supercoiling is pushed ahead of RNA polymerase.
7.2B: Supercoiling - Biology LibreTexts
2024年11月23日 · Supercoiling of DNA reduces the space and allows for much more DNA to be packaged. In prokaryotes, plectonemic supercoils are predominant, because of the circular chromosome and relatively small amount of genetic material.
Structural diversity of supercoiled DNA | Nature Communications
2015年10月12日 · Here we use electron cryo-tomography together with biochemical analyses to investigate structures of individual purified DNA minicircle topoisomers with defined degrees of supercoiling. Our...
Fast dynamics of supercoiled DNA revealed by single-molecule ... - PNAS
2007年7月17日 · The dynamics of supercoiled DNA play an important role in various cellular processes such as transcription and replication that involve DNA supercoiling. We present experiments that enhance our understanding of these dynamics by measuring the intrinsic response of single DNA molecules to sudden changes in tension or torsion.
Supercoiling and looping promote DNA base accessibility and ...
2021年9月28日 · DNA in cells is supercoiled and constrained into loops and this supercoiling and looping influence every aspect of DNA activity. We show here that negative supercoiling transmits mechanical...