Specificity, Transport Mechanism and Membrane Organization of ATP Synthases

When: Monday, March 19, 2012 at 4:00 pm
Where: DA 114
Speaker: José Faraldo-Gomez
Organization: Max-Plank, Germany
Sponsor: Physics Colloquium

ATP synthases are the most prominent source of ATP in living cells. Residing in the membranes of bacteria and mitochondria, these enzymes catalyze the conversion of ADP and Pi into ATP, through a structural mechanism that is coupled to the transmembrane flow of protons or sodium ions down their electrochemical gradients. The key coupling element in these molecular machines is a membrane-embedded turbine-like structure, known as the  c-ring. The increased availability of structural data and the close interplay of experimental methods with molecular simulations are providing novel and important insights into the mechanisms of these essential enzymes. I will present an overall summary of our recent progress in this area, particularly pertaining to the mechanism by which ion exchange across the lipid membrane is coupled to the rotation of the c-ring, as well as to the structural basis for the distinct ion-binding selectivity observed for different species. To conclude, I will describe recent investigations into the self-organization of ATP synthases in mitochondria, and speculate about its implications for membrane morphology.