Molecular characterization of PsbW, a nuclear-encoded component of the photosystem II reaction center complex in spinach.
We describe the isolation and characterization of cDNAs encoding the precursor polypeptide of the 6.1-kDa polypeptide associated with the reaction center core of the photosystem II complex from spinach. PsbW, the gene encoding this polypeptide, is present in a single copy per haploid genome. The mature polypeptide with 54 amino acid residues is characterized by a hydrophobic transmembrane segment, and, although an intrinsic membrane protein, it carries a bipartite transit peptide of 83 amino acid residues which directs the N terminus of the mature protein into the chloroplast lumen. Thylakoid integration of this polypeptide does not require a delta pH across the membrane, nor is it azide-sensitive, suggesting that the polypeptide chain inserts spontaneously in an as yet unknown way. The PsbW mRNA levels are light regulated. Similar to cytochrome b559 and PsbS, but different from the chlorophyll-complexing polypeptides D1, D2, CP43, and CP47 of photosystem II, PsbW is present in etiolated spinach seedlings.
Lorković
Z J
ZJ
Botanisches Institut, Ludwig-Maximillians-Universität, Munich, Germany.
Schröder
W P
WP
Pakrasi
H B
HB
Irrgang
K D
KD
Herrmann
R G
RG
Oelmüller
R
R
D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport; D002467:Cell Nucleus / Q000235:genetics*; D002736:Chloroplasts / Q000737:chemistry* / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D018628:Gene Dosage; D015723:Gene Library; D008027:Light; D045342:Light-Harvesting Protein Complexes; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000302:isolation & purification; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D011498:Protein Precursors / Q000235:genetics* / Q000378:metabolism; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000378:metabolism; D017422:Sequence Analysis, DNA; D018724:Spinacia oleracea / Q000235:genetics* / Q000528:radiation effects
D018076:DNA, Complementary; D045342:Light-Harvesting Protein Complexes; D008565:Membrane Proteins; D009687:Nuclear Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D011498:Protein Precursors; D011994:Recombinant Proteins