Structure and functional role of supercomplexes of IsiA and Photosystem I in cyanobacterial photosynthesis.
Cyanobacteria express large quantities of the iron stress-inducible protein IsiA under iron deficiency. IsiA can assemble into numerous types of single or double rings surrounding Photosystem I. These supercomplexes are functional in light-harvesting, empty IsiA rings are effective energy dissipaters. Electron microscopy studies of these supercomplexes show that Photosystem I trimers bind 18 IsiA copies in a single ring, whereas monomers may bind up to 35 copies in two rings. Work on mutants indicates that the PsaF/J and PsaL subunits facilitate the formation of closed rings around Photosystem I monomers but are not obligatory components in the formation of Photosystem I-IsiA supercomplexes.
Kouril
Roman
R
Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Arteni
Ana A
AA
Lax
Julia
J
Yeremenko
Nataliya
N
D'Haene
Sandrine
S
Rögner
Matthias
M
Matthijs
Hans C P
HC
Dekker
Jan P
JP
Boekema
Egbert J
EJ
D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D000458:Cyanobacteria / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D007501:Iron / Q000378:metabolism; D000090463:Iron Deficiencies; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism; D010788:Photosynthesis; D045331:Photosystem I Protein Complex / Q000737:chemistry* / Q000378:metabolism*
D001426:Bacterial Proteins; D045342:Light-Harvesting Protein Complexes; D046912:Multiprotein Complexes; D045331:Photosystem I Protein Complex; C076726:chlorophyll A binding protein CP43, Cyanobacteria; D007501:Iron