Characterization and N-terminal sequence of a 5 kDa polypeptide in the photosystem I core complex from spinach.
Photosystem I core complexes were isolated from spinach photosystem I particles after heat treatment in the presence of 50% (v/v) ethylene glycol (heat/EG treatment). The core complex from 58 degrees C/EG-treated particles was composed of polypeptides with apparent molecular masses of 63, 60 and 5 kDA; this complex contained the iron sulfur center Fx but lacked center FA and FB. The core complex obtained from the 70 degrees C/EG-treated preparation lacked FX and contained a lesser amount of the 5 kDa polypeptide. The N-terminal amino acid sequence of the 5 kDa polypeptide did not correspond to the sequence derived from any possible reading frame in the chloroplast DNA of liverwort or tobacco. Twelve of the first 29 N-terminal amino acids were hydrophobic, suggesting that this protein is intrinsic to the photosystem I reaction center.
Hoshina
S
S
Department of Biology, Faculty of Science, Kanazawa University, Japan.
Sue
S
S
Kunishima
N
N
Kamide
K
K
Wada
K
K
Itoh
S
S
D000595:Amino Acid Sequence; D002734:Chlorophyll / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D005026:Ethylene Glycols; D006358:Hot Temperature; D008027:Light; D045342:Light-Harvesting Protein Complexes; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D008970:Molecular Weight; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D010940:Plant Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid
D005026:Ethylene Glycols; D045342:Light-Harvesting Protein Complexes; D046911:Macromolecular Substances; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D010940:Plant Proteins; D002734:Chlorophyll