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Structure and functional role of supercomplexes of IsiA and Photosystem I in cyanobacterial photosynthesis
Author(s) -
Kouřil Roman,
Arteni Ana A.,
Lax Julia,
Yeremenko Nataliya,
D‧Haene Sandrine,
Rögner Matthias,
Matthijs Hans C.P.,
Dekker Jan P.,
Boekema Egbert J.
Publication year - 2005
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.03.051
Subject(s) - photosystem ii , photosystem i , photosynthesis , p700 , biophysics , cyanobacteria , biology , photosystem , chemistry , photochemistry , biochemistry , genetics , bacteria
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.