2 DISTINCT FORMS OF THE PERIDININ-CHLOROPHYLL ALPHA-PROTEIN FROM AMPHIDINIUM-CARTERAE

Peridinin-chlorophyll a-proteins (PCPs) have been purified by combinat ion of ammonium sulphate precipitation and cation exchange chromatogra phy. The amino acid sequences of several of the most abundant forms ha ve been deduced by direct protein sequencing and from DNA and indicate a highly conserved multi-gene family. At least two of the PCP genes a re tandemly arranged. A novel form of the protein was also obtained in low yield with fewer peridinins (six vs eight) per chlorophyll a and with a different molecular mass (34 kDa vs 32 kDa) of its apoprotein. It had only 31% sequence identity with any of the more abundant PCP fo rms but retained a two-domain structure.