Prof. Mills’ group uses a combination of force, torque, and fluorescence to understand how proteins remodel the structure of DNA. The group uses magnetic tweezers to pull on and twist individual DNA molecules and observe protein-induced changes in the DNA structure. Simultaneous fluorescent measurements allow for observation of orthogonal degrees of freedom, such as motions within the proteins. The group also utilizes molecular dynamics simulations to provide further information about the systems under study. Of particular interest to the group is the activity and conformational dynamics of topoisomerases, a class of protein that relaxes supercoiled DNA. Topoisomerases are essential for genome stability and are key targets for antibiotics and chemotherapeutics. The group also studies helicases, proteins that separate the strands of the DNA double helix to allow cellular machinery to access the individual strands for reading or repair.