title: Molecular analysis of the Chlamydomonas nuclear gene encoding PsbW and demonstration that PsbW is a subunit of photosystem II, but not photosystem I.
abstract: PsbW is a nuclear-encoded protein located in the thylakoid membrane of the chloroplast. Studies in higher plants have provided substantial evidence that PsbW is a core component of photosystem II. However, recent data have been presented to suggest that PsbW is also a subunit of photosystem I. Such a sharing of subunits between the two photosystems would represent a novel phenomenon. To investigate this, we have cloned and characterized the psbW gene from the green alga Chlamydomonas reinhardtii. The gene is split by five introns and encodes a polypeptide of 115 residues comprising the 6.1 kDa mature PsbW protein preceded by a 59 amino acid bipartite transit sequence. Using antibodies raised to PsbW we have examined: (1) C. reinhardtii mutants lacking either photosystem and (2) purified photosystem preparations. We find that PsbW is a subunit of photosystem II, but not photosystem I.
authors.affiliation: Photosynthesis Research Group, Department of Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Cleo L
authors.initials: CL
authors.lastname: Bishop
authors.forename: Saul
authors.initials: S
authors.lastname: Purton
authors.forename: Jonathan H A
authors.initials: JH
authors.lastname: Nugent
mesh_terms: D020418:Algal Proteins / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000235:genetics; D016825:Chlamydomonas reinhardtii / Q000235:genetics* / Q000528:radiation effects; D005091:Exons; D005796:Genes / Q000235:genetics; D007438:Introns; D008027:Light; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics*; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D013696:Temperature; D020524:Thylakoids / Q000378:metabolism
chemical_list: D020418:Algal Proteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins