Membranes are essential for the existence of life as we know it because they define a barrier between the inside and outside of an organism. However, cells also need to exchange nutrients, chemicals and information with the environment, which they achieve with the help of proteins embedded into the membrane that serve as specific and efficient gateways. The crucial role of membrane proteins is underscored by the fact that they are encoded by around one third of a given genome and constitute over half of the FDA-approved drug targets.
Available membrane protein structures have revealed an abundance of symmetric and pseudo-symmetric architectures. Using the striking example of the mitochondrial ADP/ATP carrier, which is responsible for replenishing the metabolic energy of the living cell, I will demonstrate that this structural symmetry can often be key to deciphering how the protein functions. In this context, a systematic study of symmetry should provide a framework for a broader understanding of the mechanistic principles and evolutionary development of membrane proteins. I will therefore explain our efforts to design a robust symmetry detection algorithm and incorporate the results into a publicly accessible database called EncoMPASS (encompass.ninds.nih.gov). EncoMPASS can be used not only to examine specific membrane proteins but also to address general questions related to this important and fascinating class of proteins.