DNA helicase

DNA helicase is an enzyme responsible for the separation of two annealed strands of nucleic acids. It binds to the double stranded DNA, and breaks the hydrogen bonds between the strands. This process allows a single-stranded DNA to form and be used as a template during transcription. ATP hydrolysis provides the energy for the enzyme to translocate along the double helix and generate a replication fork. In E. coli DNA helicase is called the DnaB protein, and it differs slightly in the way it carries out it's function. DnaB forms a three-fold ring structure, with the lagging strand binding in the central region, whilst the leading strand is excluded. The DnaB translocates through a mechanism where dNTP's bind and cause a conformational change, forcing the DNA strands to separate.