Light-harvesting photosynthetic bile pigment-protein from the phycobiliprotein complex. Heterotetramer of 2 identical alpha chains and 2 identical beta chains which form 2 alpha-beta heterodimers within the heterotetramer. The two alpha-beta heterodimers are rotated to an open configuration in contrast to the closed configuration found in other cryptophyte species due to the insertion of a single amino acid, 'Asp-65', in a conserved region of the alpha chain. In the open form, the central chromophores are not in physical contact but are separated by a water-filled channel. Contains three phycocyanobilin chromophores and one 15,16-dihydrobiliverdin chromophore with binding of the phycocyanobilin chromophores mediated by both the alpha and beta subunits. The light-harvesting system in Cryptophytes contains phycobiliprotein complexes. Unusually they are composed of either phycoerythrin (CPE) or phycocyanin (CPC) but never allophycocyanin (APC), with only one type of biliprotein being present in any one species. Unlike cyanobacteria or red algae these proteins are not arranged into higher-order phycobilisome complexes, and they are found in the thylakoid lumen. Belongs to the phycobiliprotein family.