title: Amino acid composition of the 9 kDa phosphoprotein of pea thylakoids.
abstract: The 9 kDa phosphoprotein of pea thylakoids was isolated by electroelution from SDS-polyacrylamide gels and its amino acid composition determined. The result is at variance with the amino acid compositions predicted from published nucleotide sequences of the genes for apocytochrome b-559 and for CFo subunit III. The amino acid composition of the 9 kDa phosphoprotein resembles that of the 25 kDa light-harvesting chlorophyll a/b protein (LHC-II). We propose that the 9 kDa polypeptide is a chlorophyll-binding protein of photosystem II, that it functions as a link in excitation energy transfer between LHC-II and the reaction centre, and that its phosphorylation regulates excitation energy distribution by means of mutual electrostatic repulsion between itself and phosphorylated LHC-II.
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D001483:Base Sequence; D002734:Chlorophyll / Q000032:analysis; D002736:Chloroplasts / Q000032:analysis; D003573:Cytochrome b Group / Q000235:genetics; D004247:DNA / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D045342:Light-Harvesting Protein Complexes; D008970:Molecular Weight; D010750:Phosphoproteins / Q000032:analysis*; D010766:Phosphorylation; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins / Q000032:analysis*; D014675:Vegetables
chemical_list: D000596:Amino Acids; D003573:Cytochrome b Group; D045342:Light-Harvesting Protein Complexes; D010750:Phosphoproteins; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D002734:Chlorophyll; D004247:DNA; C019313:cytochrome b559