Research Area A

Structures, Mechanisms and Dynamics of Membrane Complexes and Membranes

Membranes define the cell and its compartments. Proteins and protein complexes in these lipid bilayers carry out fundamental cellular functions, from basic energy conversion, active and passive uptake of metabolites, signal recognition and transduction, to cell-cell interaction and tissue formation. Frankfurt is one of the world´s leading centers in the study of membrane proteins, membrane complexes and their molecular mechanisms. In CEF major breakthroughs were achieved in this demanding area, including a 6 Å map of mitochondrial complex I, high-resolution structures of cytochrome cbb3 oxidase, and of two new secondary transporters. In CEF scientists took advantage of the outstanding research environment, which enabled them to study membrane protein complexes by electronmicroscopy, x-ray crystallography and a wide range of biophysical and spectroscopic techniques, including EPR, liquid- and solid-state NMR spectroscopy. They obtained structural and mechanistic information on different classes of membrane transport proteins and complexes, and intensified the detailed investigation of function and cooperativity in secondary transporters, as well as the structure and dynamics of the MHC-I antigen-loading complex. They applied state-of-the-art light, correlative fluorescence and electron microscopy as well as electron cryo-tomography to image large complexes at high resolution. With these techniques they were able to describe the dynamic association of membrane proteins into large assemblies, and how the formation and disintegration of such assemblies governs membrane plasticity and cellular function. A particular focus concentrated on mitochondria.