Attaches a phycocyanobilin (PCB) chromophore to 'Cys-82' of the C-phycocyanain beta subunit (PhcB) and the unique PCB that is attached to allophycocyanin alpha and beta subunits (ApcA and ApcB). In vitro, and probably also in vivo, chromophorylates ApcD and ApcF. Forms a heterodimer with CpcU. Cells are a yellow color, 70% reduction in phycobiliproteins, grow slowly, have an increased sensitivity to high light and a long lag phase. The C-phycocyanin beta subunit (PhcB) in this strain is missing the phycocyanobilin chromophore on 'Cys-82'. Belongs to the CpcS/CpeS biliprotein lyase family.