title: Novel approach reveals localisation and assembly pathway of the PsbS and PsbW proteins into the photosystem II dimer.
abstract: A blue-native gel electrophoresis system was combined with an in organello import assay to specifically analyse the location and assembly of two nuclear-encoded photosystem II (PSII) subunits. With this method we were able to show that initially the low molecular mass PsbW protein is not associated with the monomeric form of PSII. Instead a proportion of newly imported PsbW is directly assembled in dimeric PSII supercomplexes with very fast kinetics; its negatively charged N-terminal domain is essential for this process. The chlorophyll-binding PsbS protein, which is involved in energy dissipation, is first detected in the monomeric PSII subcomplexes, and only at later time points in the dimeric form of PSII. It seems to be bound tighter to the PSII core complex than to light harvesting complex II. These data point to radically different assembly pathways for different PSII subunits.
authors.affiliation: Arrhenius Laboratories for Natural Sciences, Department of Biochemistry and Biophysics, Stockholm University, SE-106 91, Stockholm, Sweden.
authors.forename: Ellinor
authors.initials: E
authors.lastname: Thidholm
authors.forename: Viktoria
authors.initials: V
authors.lastname: Lindström
authors.forename: Christophe
authors.initials: C
authors.lastname: Tissier
authors.forename: Colin
authors.initials: C
authors.lastname: Robinson
authors.forename: Wolfgang P
authors.initials: WP
authors.lastname: Schröder
authors.forename: Christiane
authors.initials: C
authors.lastname: Funk
mesh_terms: D002736:Chloroplasts / Q000378:metabolism*; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D045342:Light-Harvesting Protein Complexes; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D018532:Pisum sativum / Q000378:metabolism*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D013997:Time Factors
chemical_list: 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