Understanding the mechanisms of membrane proteins entails complementing static structures with the conformational changes in the structure. Recent advances in Double Electron-Electron Resonance (DEER) spectroscopy along with computational methods to generate restrained models of proteins are enabling unprecedented insights into the conformational dynamics of active transporters. My laboratory use EPR methods to define conformational equilibria that mediate the transport cycle of ion-coupled symporters and antiporters as well as ABC transporters. I will describe comparative analysis of ATP-binding cassette (ABC) exporters that reveals the role of dynamics in their transport cycles that resolve long standing question in the field . Together, these studies are illuminating the mechansitic commonalities and differences in the family.