Localization of ?-phycoerythrin to the thylakoid lumen of Cryptomonas ? does not involve a signal peptide

Recent investigations have shown that, in cryptomonads, the phycobiliproteins are located within the thylakoid lumen rather than on the stromal side of this membrane as found in cyanobacteria and red algae. To examine possible mechanisms involved in targeting this protein to the thylakoid lumen, the plastid-encoded cpeB gene from Cryptomonas phi was sequenced. This gene encodes an open reading frame of 177 amino acids that is highly similar to...