Determination of catabolism of the photosystem II D 1 subunit by structural motifs in the polypeptide sequence.
Proteolytic mapping of the D 1 subunit of photosystem two and a degradation product which arises during its rapid catabolism shows that the latter is a result of proteolysis within the peptide motif QEEET. This motif is located in a portion of the D 1 protein thought to form a stroma-exposed connection between fourth and fifth transmembrane segments. This connection domain also contains a "PEST"-like sequence and forms part of the QB/herbicide binding niche. The QEEET motif seems to provide a major epitope in immunological studies, as judged from reaction of D 1 and its fragments with polyclonal antibodies. Antibodies against D 1 were found to react with other animal and plant proteins which contain similar sequence motifs.
Department of Biochemistry, Imperial College, London, U.K.
C A
CA
Shipton
J B
JB
Marder
J
J
Barber
D000595:Amino Acid Sequence; D002734:Chlorophyll / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D045342:Light-Harvesting Protein Complexes; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010449:Peptide Mapping; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010944:Plants / Q000378:metabolism*; D011487:Protein Conformation; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
D045342:Light-Harvesting Protein Complexes; D046911:Macromolecular Substances; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D002734:Chlorophyll