Figure 1.

Possible translocation mechanisms of helicases. (A) The helicase can be passive, trapping fork fluctuations through an ATP‐driven progression. Alternatively, helicases can actively unwind DNA (B) as they progress along by a “rolling model” where each monomer takes turn at unwinding the molecule or (C) by driving a “plow” through the DNA fork or (D) pulling the DNA through the helicase as in some hexameric helicases. So far all these mechanisms are found in helicase with the exception of the rolling model which had not been demonstrated experimentally for any helicase.