title: Three-dimensional structure of the higher-plant photosystem II reaction centre and evidence for its dimeric organization in vivo.
abstract: The three-dimensional structure of photosystem II (PSII) has been determined by conventional transmission electron microscopy and computerized three-dimensional reconstruction. Both the complete system and that lacking the oxygen-evolving complex have been analyzed. The PSII complex has a four-lobed structure with twofold symmetry. An estimate of the molecular mass and the results of Deriphat/PAGE analysis suggest that a reaction centre is present in each half of the structure resolved by electron microscopy. Stepwise removal of components of the complex showed that the removal of CP47 (a 47-kDa chlorophyll-protein complex) induces monomerization of PSII, which indicates the importance of this subunit for the dimeric structure.
authors.affiliation: Dipartimento di Biologia, Università di Padova, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Santini
authors.forename: V
authors.initials: V
authors.lastname: Tidu
authors.forename: G
authors.initials: G
authors.lastname: Tognon
authors.forename: A
authors.initials: A
authors.lastname: Ghiretti Magaldi
authors.forename: R
authors.initials: R
authors.lastname: Bassi
mesh_terms: D002462:Cell Membrane / Q000737:chemistry; D002736:Chloroplasts / Q000737:chemistry / Q000648:ultrastructure; D003198:Computer Simulation; D004591:Electrophoresis, Polyacrylamide Gel; D007091:Image Processing, Computer-Assisted; D007425:Intracellular Membranes / Q000737:chemistry; D045342:Light-Harvesting Protein Complexes; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D008958:Models, Molecular; D008970:Molecular Weight; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000648:ultrastructure; D045332:Photosystem II Protein Complex; D003313:Zea mays / Q000737:chemistry
chemical_list: D045342:Light-Harvesting Protein Complexes; D046911:Macromolecular Substances; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex