A genomic clone encoding a cryptophyte phycoerythrin α-subunit Evidence for three α-subunits and an N-terminal membrane transit sequence

AbstractA genomic library of Chroomonas (Cryptophyceae) DNA has been constructed in λEMBL4. Using a synthetic oligomer as a hybridization probe, a clone containing a phycoerythrin α-subunit has been obtained and sequenced. The principal α1 and α2-subunits of the holoprotein have been partially sequenced by sequential Edman degradation and differ from the DNA derived sequence, providing evidence for at least 3 α-subunit genes. The nucleotide sequence of the α-subunit gene is GC rich and encodes an N-terminal extension which is putatively thylakoid-lumen directing