DNA Helicases

The helicases involved in DNA replication are known as replicative helicases. They contain six subunits that surround a central pore large enough to allow single-stranded DNA to pass through.

Helicase undergoes a conformational change In order to move along the DNA using the energy from ATP hydrolysis.

Each of the six subunits of helicase has an ATP binding site with inherent ATPase activity, which is the ability to break down ATP to ADP and inorganic phosphate.

As helicase breaks down ATP, the subunits move relative to each other causing DNA translocation.

To begin unwinding DNA, helicase binds to a single strand of the DNA at the origin of the replication and slides along the selected strand of DNA.