The bacterial flagellar motor is a molecular engine designed by nature to allow flagellated bacteria to swim. The aim of the proposed research is to understand the molecular mechanism of rotation through the study of the structure and dynamics of the power-generating unit of the motor. A multidisciplinary approach will be used to investigate how the stator ring assembles, anchors to the cell wall and interacts with the rotor. The research will test a hypothesis that rotation is driven by cyclic conformational changes in the stator ring. This study should allow formulation of a justified model of how this rotary nanoscale machine converts the electrochemical energy of the proton gradient into the mechanical energy of rotation.