membrane-bound pigment-binding polypeptides and very similar principles of organization, realized, for example, in the photochemical reaction center and the ubiquinone-cytochrome blc oxidoreductase of many evolutionary remote organisms. l The bacterial photosynthetic and respiratory apparatuses are much simpler in composition and organization than the corresponding structures of higher organisms. They are, therefore, excellent model systems to study correlations between structure and function and assembly of these highly organized membrane particles. Biophysicists, biochemists and molecular biologists have in close cooperation, but using different methodical approaches, reached a clear progress in this field. From the 150 contributions to the Symposium on molecular biology of membrane-bound complexes in phototrophic bacteria (Freiburg, August 2-5, 1989) 56 representative papers have been selected and combined in this volume.