Our lab is interested in the molecular basis of muscle contraction. Our focus is the structure of the actin and myosin filaments, which slide past each other to generate force and shortening. We are especially interested in the molecular switches that turn contraction on and off. We investigate these questions using electron microscopy and image analysis to determine the three-dimensional structure of the actin and myosin filaments and their component molecules. We also use time-resolved electron microscopic techniques to capture transient structural changes occurring on activation. Our studies cover all three types of muscle – skeletal, cardiac and smooth muscles. Some muscle diseases result from mutations in actin, myosin and associated molecules: our studies provide a structural basis for understanding these diseases.