Phycoerythrocyanin is a kind of phycobiliprotein, magenta chromoprotein involved in photosynthesis of some Cyanobacteria.
[1] This chromoprotein consists of alpha- and beta-subunits, generally aggregated as hexamer.
Phycoerythrocyanin is similar to phycocyanin, an important component of the light-harvesting complex (phycobilisome) of cyanobacteria and red algae.
While only phycocyanobilin is covalently bound to phycocyanin, leading to an absorption maximum around 620 nm, phycoerythrocyanin containing both phycoviolobilin and phycocyanobilin leads to an absorption maximum around 575 nm.
Finally, the light energy absorbed by phycoerythrocyanin is transferred to photosynthetic reaction center.