Covalently attaches a chromophore to Cys residue(s) of phycobiliproteins (By similarity). In vitro is not seen to act as a chromophore lyase for ApcA1, ApcA2, ApcB, ApcD, ApcF, CpcB or PecB, the lyase activity is therefore unsure. Induced by nitrogen starvation. Belongs to the CpcT/CpeT biliprotein lyase family.