question: Which are the major phycobiliproteins present in cyanobacteria?
answer: Phycobiliproteins are derived from the photosynthetic apparatus of cyanobacteria and eukaryotic algae, and form their large extrinsic antenna complexes called phycobilisomes. Phycobilisomes have a core composed from allophycocyanin (APC) and rods, which are of variable phycobiliprotein composition. C-Phycocyanin (C-Pc) is one of the major light harvesting biliprotein pigments constitutively produced by many cyanobacteria, such as Spirulina platenesis (a blue-green alga). B-Phycoerythrin (B-PE) is an other major light-harvesting pigment found in red algae and cyanobacteria. R-phycoerythrin (R-PE) is the major light-harvesting pigment protein of most red algal phycobilisomes.