RecA-like motor ATPases--lessons from structures.

A large class of ATPases contains a RecA-like structural domain and uses the energy of nucleotide binding and hydrolysis to perform mechanical work, for example, to move polypeptides or nucleic acids. These ATPases include helicases, ABC transporters, clamp loaders, and proteases. The functional units of the ATPases contain different numbers of RecA-like domains, but the nucleotide is always bound at the interface between two adjacent RecA-like folds and the two domains move relative to one another during the ATPase cycle. The structures determined for different RecA-like motor ATPases begin to reveal how they move macromolecules.