In 1988 he received the Nobel Prize for Chemistry jointly with Johann Deisenhofer and Hartmut Michel. The trio were recognized for their work in first crystallizing an intramembrane protein important in photosynthesis in purple bacteria, and subsequently applying X-ray crystallography to elucidate the protein's structure. The information provided the first insight into the structural bodies that performed the integral function of photosynthesis. This insight could be translated to understand the more complex analogue of photosynthesis in cyanobacteria which is essentially the same as that in chloroplasts of higher plants.