Phycobilisomes

The light harvesting complex for photosystem II (PSII) in cyanobacteria >95% of the light they absorb is passed to PSII. PBS core: composed of 2 or more commonly 3 cylinders. These core cylinders are composed of a stack of 4 discs. The cylinders form a triangular prism. Radiating from 2 sides of this core are 6 peripheral rod substructures : each rod is composed of a stack of discs. The number of discs per rod can range from 2-6 and is dependent on the source of the organism and the nutrient conditions employed. PBS are composed of 2 types of protein : phycobiliproteins and linker polypepetides.