The photosynthetic megacomplex from a cyanobacterium, which scientists have managed to isolate in its complete, functioning form, weighs about 6 million Daltons. It has three parts: on top is a light-harvesting antenna complex called a phycobilisome that captures and funnels the energy in sunlight to two reaction centers, Photosystem II (the complex protruding beneath the antenna) and Photosystem I (the complexes to either side Photosystem II). The megacomplex is embedded in a membrane shown as a green carpet.

More details regarding this research can be found in a recent news release (https://news.wustl.edu/news/Pages/26091.aspx) or the article in Science (Phycobilisomes Supply Excitations to Both Photosystems in a Megacomplex in Cyanobacteria).