Covalently attaches a chromophore to Cys residue(s) of phycobiliproteins. No visible phenotype; a triple cpcS/cpcU/cpcV deletion mutant has decreased amounts of allophycocyanin beta subunit (ApcB) compared to a double cpcS/cpcU deletion mutant. The lyase activity is therefore unsure. Belongs to the CpcS/CpeS biliprotein lyase family. Truncated N-terminus.