Light-harvesting photosynthetic bile pigment-protein from the phycobiliprotein complex (phycobilisome, PBS). Phycocyanin is the major phycobiliprotein in the PBS rod. Heterodimer of an alpha and a beta subunit, which further assembles into trimers and the trimers into hexamers. Part of the phycobilisome rod. Contains one covalently linked phycocyanobilin chromophore. The measured mass is that of the protein plus one covalently linked phycocyanobilin chromophore. Belongs to the phycobiliprotein family.