Hydrolysis of ATP is used to drive conformational changes in enzymes, leading to mechanical work that is used for molecular transport, communication, and motility.
Protein secretion is a fundamental process for all cells. In bacteria, most protein secretion is done by the SecA ATPase and SecYEG, a membrane pore. The “DEAD Motor” domains of SecA are shown in the movie below. These domains represent about 40% of the SecA molecule and use the chemical energy of ATP to do the mechanical work of pushing unfolded pre-proteins across the cytoplasmic membrane. The DEAD Motor has three different conformations that are affected by binding and hydrolysis of ATP. Our research is focussed on understanding how these ATP-driven conformational changes in the DEAD Motor are used to move the preprotein substrate across the membrane.