Corporate Banner
Satellite Banner
Scientific Community
Become a Member | Sign in
Home>News>This Article

Random Walks on DNA

Published: Monday, April 22, 2013
Last Updated: Monday, April 22, 2013
Bookmark and Share
Scientists have revealed how a bacterial enzyme has evolved an energy-efficient method to move long distances along DNA.

The findings, published in Science, present further insight into the coupling of chemical and mechanical energy by a class of enzymes called helicases, a widely-distributed group of proteins, which in human cells are implicated in some cancers.

The new helicase mechanism discovered in this study, led by researchers from the University of Bristol and the Technische Universität Dresden in Germany, may help resolve some of the unexplained roles for helicases in human biology, and in turn help researchers to develop future technological or medical applications.

A commonly held view of DNA helicases is that they move along DNA and “unzip” the double helix to produce single strands of DNA for repair or copying. This process requires mechanical work, so enzyme movement must be coupled to consumption of the chemical fuel ATP. These enzymes are thus often considered as molecular motors.

In the new work, Ralf Seidel and his team at the Technische Universität Dresden developed a microscope that can stretch single DNA molecules whilst at the same time observe the movement of single fluorescently-labelled helicases. In parallel, the Bristol researchers in the DNA-Protein Interactions Unit used millisecond-resolution fluorescence spectroscopy to reveal dynamic changes in protein conformation and the kinetics of ATP consumption.

The team studied a helicase found in bacteria that moves along viral (bacteriophage) DNA. The work demonstrated that, surprisingly, the enzyme only consumed ATP at the start of the reaction in order to change conformation. Thereafter long-range movement along the DNA was driven by thermal motion; in other words by collisions with the surrounding water molecules. This produces a characteristic one-dimensional “random walk” (see picture), where the protein is just as likely to move backwards as forwards.

Mark Szczelkun, Professor of Biochemistry from the University’s School of Biochemistry and one of the senior authors of the study, said: “This enzyme uses the energy from ATP to force a change in protein conformation rather than to unwind DNA. The movement on DNA thereafter doesn’t require an energy input from ATP. Although movement is random, it occurs very rapidly and the enzyme can cover long distances on DNA faster than many ATP-driven motors. This can be thought of as a more energy-efficient way to move along DNA and we suggest that this mechanism may be used in other genetic processes, such as DNA repair.”

The work in Bristol has been funded by the Wellcome Trust through a programme grant to Professor Mark Szczelkun from the School of Biochemistry.

Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,500+ scientific posters on ePosters
  • More than 5,200+ scientific videos on LabTube
  • 35 community eNewsletters

Sign In

Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Manipulation of Protein Could Help Stop Spread of Cancer Cells
New findings, published in the Nature journal Oncogene, reveal how a protein, PRH, is normally able to prevent cells from unnecessary migration.
Monday, November 18, 2013
Sixteen New Genetic Regions for Allergies Discovered
Regions discovered during two of the largest genetic studies ever conducted on common allergies, including pollen, dust-mite and cat allergies.
Monday, July 01, 2013
Scientific News
Integrated Omics Analysis
Studying multi-omics promises to give a more holistic picture of the organism and its place in its ecosystem, however despite the complexities involved those within the field are optimistic.
Unravelling the Role of Key Genes and DNA Methylation in Blood Cell Malignancies
Researchers from the University of Nebraska Medical Center have demonstrated the role of Dnmt3a in safeguarding normal haematopoiesis.
Drug Target for Triple-Negative Breast Cancer Found
A team of researchers led by UC San Francisco scientists has identified a new drug target for triple-negative breast cancer.
Wrapping up the Genome
Researchers successfully package complete yeast genome using purified components, yielding new insights into genome mechanisms.
Gene Therapy Going Global with Portable Device
Portable 'gene therapy in a box' could make future cancer and HIV cures affordable in developing countries.
Smartphone Laboratory Detects Cancer
Researchers develop low-cost, portable laboratory on a smartphonecapable of analysing multiple samples simultaneously.
Fighting Cancer with Immune Response
New treatment elicits two-pronged immune response that destroys tumors in mice.
Nanomedicine for Breast Cancer Treatment
Using nanoparticles measuring only billionths of a meter in size, doctors are able to deliver drug molecules directly to the affected tissue.
Zika Virus Infection Alters Human and Viral RNA
Researchers have discovered that Zika infections results in human and viral genetic modification.
Cell Metabolism Linked to Spread of Cancer
Scientists discover macrophage metabolism can be attuned to prevent the spread of cancer.
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
5,200+ scientific videos