helicase

(noun)

an enzyme that unwinds the DNA helix ahead of the replication machinery

Related Terms

Examples of helicase in the following topics:

  • DNA Replication in Eukaryotes

    • Two copies of an enzyme called helicase are among the proteins recruited to the origin.
    • Each helicase unwinds and separates the DNA helix into single-stranded DNA.
    • The "leading strand" is synthesized continuously toward the replication fork as helicase unwinds the template double-stranded DNA.
    • The "lagging strand" is synthesized in the direction away from the replication fork and away from the DNA helicase unwinds.
    • A replication fork is formed by the opening of the origin of replication; helicase separates the DNA strands.

  • DNA Replication in Prokaryotes

    • An enzyme called helicase unwinds the DNA by breaking the hydrogen bonds between the nitrogenous base pairs.
    • A replication fork is formed when helicase separates the DNA strands at the origin of replication.

  • Elongation and Termination in Eukaryotes

    • Specific subunits within the protein allow RNA Polymerase II to act as its own helicase, sliding clamp, single-stranded DNA binding protein, as well as carry out other functions.