Related Experiment Video
Updated: Jun 2, 2026

Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
The torsional state of DNA within the chromosome
1Instituto de Biología Molecular de Barcelona, CSIC, Baldiri Reixac, Barcelona, Spain. joaquim.roca@ibmb.csic.es
Abstract:
Virtually all processes of the genome biology affect or are affected by the torsional state of DNA. Torsional energy associated with an altered twist facilitates or hinders the melting of the double helix, its molecular interactions, and its spatial folding in the form of supercoils. Yet, understanding how the torsional state of DNA is modulated remains a challenging task due to the multiplicity of cellular factors involved in the generation, transmission, and dissipation of DNA twisting forces. Here, an overview of the implication of DNA topoisomerases, DNA revolving motors, and other DNA interactions that determine local levels of torsional stress in bacterial and eukaryotic chromosomes is provided. Particular emphasis is made on the experimental approaches being developed to assess the torsional state of intracellular DNA and its organization into topological domains.
Related Concept Videos
DNA Topoisomerases
Types and Mechanism of action
Topoisomerases are divided into two main types. Type I...
Chromosome Structure
The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division.
Telomeres consist of non-coding repetitive nucleotide...
Chromosome Structure
The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division.
Telomeres consist of non-coding repetitive nucleotide...
Forces Acting on Chromosomes
Microtubules and motor proteins exert two types of forces on...
Forces Acting on Chromosomes
Microtubules and motor proteins exert two types of forces on...
Chromatin Packaging
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.

