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).

In this review we will focus on the role of DNA supercoiling in the cellular processes, with particular emphasis on transcription.

2024年11月23日 · DNA supercoiling refers to the over- or under-winding of a DNA strand, and is an expression of the strain on that strand. Supercoiling is important in a number of biological processes, such as compacting DNA.

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).

Supercoiling is a fundamental property of DNA and chromatin. It is modulated by polymerase and topoisomerase activities and, through regulated constraint, by DNA/chromatin binding proteins.

2022年3月30日 · DNA supercoiling is a higher-order organization of DNA which is known as DNA packaging. It allows the winding and interwinding of DNA on and with one another. This process has many important functions. Two types of DNA supercoiling processes are positive supercoiling and negative supercoiling.

This results in the creation and accumulation of overwound (positively supercoiled) DNA ahead of the polymerases and underwound (negatively supercoiled) DNA behind. The positive supercoils are removed by DNA gyrase in a reaction that is dependent on ATP hydrolysis.

DNA supercoiling acts as a global and ancestral regulator of bacterial gene expression. In this review, we advocate that it plays a pivotal role in host-pathogen interactions by transducing environmental signals to the bacterial chromosome and coordinating its transcriptional response.

2023年10月30日 · We discuss more particularly the problem of DNA conformations, the interplay between DNA supercoiling with gene transcription and DNA replication, its role on nucleoid formation and, finally, the problem of scaling up models.

2025年1月12日 · DNA supercoiling is a fascinating aspect of genomic architecture that significantly influences DNA function and stability. Supercoiling refers to the overwinding or underwinding of the DNA helix, which occurs due to the helical nature of DNA. This phenomenon arises naturally during various cellular processes, such as transcription and ...