title: PSI-O, a new 10-kDa subunit of eukaryotic photosystem I.
abstract: A novel polypeptide with an apparent molecular mass of 9 kDa was detected after sodium dodecyl sulphate-polyacrylamide gel electrophoresis of Arabidopsis photosystem I (PSI) and was N-terminally sequenced. Corresponding cDNA clones encode a precursor protein of 140 amino acid residues which was imported into isolated intact chloroplasts and processed to the mature protein, designated PSI-O. The mature protein has two transmembrane helices and a calculated mass of 10104 Da. The PSI-O protein was also shown to be present in PSI isolated from barley and spinach, and was essentially absent in chloroplast grana. Expressed sequences encoding similar proteins are available from many species of plants and green algae.
authors.affiliation: Plant Biochemistry Laboratory, Department of Plant Biology, The Royal Veterinary and Agricultural University, 40 Thorvaldsensvej, DK-1871 Frederiksberg C, Copenhagen, Denmark.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Knoetzel
authors.forename: Alexandra
authors.initials: A
authors.lastname: Mant
authors.forename: Anna
authors.initials: A
authors.lastname: Haldrup
authors.forename: Poul Erik
authors.initials: PE
authors.lastname: Jensen
authors.forename: Henrik Vibe
authors.initials: HV
authors.lastname: Scheller
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis; D002736:Chloroplasts / Q000737:chemistry / Q000378:metabolism; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D001467:Hordeum; D007425:Intracellular Membranes / Q000737:chemistry / Q000378:metabolism; D008970:Molecular Weight; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D045331:Photosystem I Protein Complex; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics; D011499:Protein Processing, Post-Translational; D021122:Protein Subunits; D020539:Sequence Analysis, Protein; D018724:Spinacia oleracea
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; D010940:Plant Proteins; D021122:Protein Subunits