Since this BAG is composed of 7 different working groups from 3 different locations (universities of Cologne, Bochum and Düsseldorf), the projects within this proposal are of rather heterogeneous nature. Nonetheless, we are focusing on five main topics: 1.) proteins involved in transport processes, transporters or channels, either embedded in the membrane or acting in the cytosol (e. g. ABC transporters, resistance proteins) 2.) proteins involved in the immune system or resistance processes of prokaryotic bacteria and plants (dehydratases, cyclases, binding proteins) 3.) proteins involved or associated with diseases like cancer or developmental disorders (e. g. metallopeptidase, protein kinase, chaperones) 4.) enzymes of putative industrial use in order to encounter increasing environmental pollution (e. g. transaminases, estereases) 5.) proteins involved in synthesis of light harvesting pigments and chromophore binding proteins (e. g. reductases, photosensor domains)