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). Forms a heterodimer with CpcS. 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.