Dictionary > Helicase

Helicase

Definition
noun, plural: helicases
An enzyme that utilizes energy from nucleoside triphosphate (e.g. ATP) hydrolysis in order to unwind the two annealed nucleic acid strands (e.g. DNA)
Supplement
DNA is a helical, double-stranded molecule that bears the genetic code. During the replication of DNA, its two strands are separated from each other resulting in a configuration called the replication fork. The replication fork is comprised of two prongs wherein each prong is the single strand of DNA. The replication fork results from the work of the helicases. Helicases are enzymes that are used by living organisms to separate the strands of nucleic acids, and in this case, the double-stranded DNA. Helicases do so by breaking the hydrogen bonds that hold the two strands together. Helicases are able to do this by utilizing energy from the hydrolysis of nucleoside triphosphates (e.g. ATPs). Apart from DNA replication, helicases are also used in transcription, translation, recombination, DNA repair, and ribosome biogenesis. DNA helicases were first discovered and isolated in E.coli in 1976.1
See also:

Related term(s):

  • Dead box helicase
  • Repb helicase
  • Repd helicase
  • Reference(s):

    1 Abdel-Monem M, Dürwald H, Hoffmann-Berling H (June 1976). “Enzymic unwinding of DNA. 2. Chain separation by an ATP-dependent DNA unwinding enzyme”. Eur. J. Biochem. 65 (2): 441–9.


    You will also like...

    Early Mammals on Earth
    Early Mammals on Earth

    The Earth's ecosphere was rapidly changing and throwing up a wide range of ecological niches that new adaptive organisms..

    Biological Energy
    ATP & ADP – Biological Energy

    ATP is the energy source that is typically used by an organism in its daily activities. The name is based on its structu..

    Biosecurity and Biocontrol
    Biosecurity and Biocontrol

    This lesson explores the impact of biosecurity threats, and why they need to be identified and managed. Examples to incl..

    Hormone Production
    Hormone Production

    Hormones are chemical messengers produced by specialized glands and they were produced by switching on the genes designe..

    Ecological Research Measuring & Analysis
    Ecological Research: Measuring & Analysis

    This lesson is about the methods used for ecological research, such as quadrat and transect sampling, canopy fogging, an..

    A sperm cell fertilizing an ovum
    Human Reproduction and Fertilization

    For human species to obviate extinction, reproductive mature adults should be producing viable offspring in order to con..