Proteins are the major active components of living cells. They have to fulfill their various tasks in a highly coordinated, time resolved and spatial fashion. Metabolic channeling of sensitive intermediates of pathways, polymerizing/depolymerizing mobile structures or signal transfer processes, all require highly specific, but often transient protein-protein interactions. Many proteins are often subject to a fine-tuned, controlled assembly for the formation of higher ordered complexes. In contrast to the obvious importance of these cellular processes, our current knowledge of the underlying molecular principles is limited. Therefore, the new RTG proposes a broad methodical approach for the investigation of different types of protein assembly. On purpose, we will focus our research on two major types of model protein complexes, one for metabolic channeling and the other for electron transfer. This approach guarantees the interdisciplinary cooperation within the consortium. Along these lines, the innovative character of the proposal is reflected by combining the theoretical and experimental expertise from an indisciplinary group of scientists that use highly advanced techniques. A broad methodological spectrum will be employed ranging from biochemical and molecular methods, such as advanced cloning, enzyme purification, recombinant protein production in bacteria, yeast, insects and animal cells, bioinformatics and systems biology, HPLC, GC, all kinds of MS, diverse kinds of spectroscopy, proteininteraction approaches up to the level of single molecule spectroscopy, X-ray crystallography, proteomics and live cell imaging. This broad scientific approach to the field using multiple distinct methods provides the solid basis for an inspiring, sophisticated and cross-disciplinary educational program. It combines lecture series, PhD seminars, methods workshops with "lab-swaps", a visiting program, participation in international symposia and time abroad. It guarantees intensive research-focused learning at the foremost front of science. Our selection procedures ensure participation of excellent research students and consider gender equality and parenthood issues. The major goal of the RTG is the education of theoretically and practically competent and internationally highly competitive young researchers for academics and industry.