TY - JOUR
T1 - Evidence that cytochrome b559 mediates the oxidation of reduced plastoquinone in the dark
AU - Bondarava, Natallia
AU - De Pascalis, Luca
AU - Al-Babili, Salim
AU - Goussias, Charilaos
AU - Golecki, Jochen R.
AU - Beyer, Peter
AU - Bock, Ralph
AU - Krieger-Liszkay, Anja
PY - 2003/4/11
Y1 - 2003/4/11
N2 - The function of cytochrome b559 in photosystem II (PSII) was investigated using a mutant created in tobacco in which the conserved phenylalanine at position 26 in the β-subunit (PsbF) was changed to serine (Bock, R., Kössel, H., and Maliga, P. (1994) EMBO J. 13, 4623-4628). The mutant grew photoautotrophically, but the amount of PSII was reduced and the ultrastructure of the chloroplast was dramatically altered. Very few grana stacks were formed in the mutant. Although isolated PSII-enriched membrane fragments showed low PSII activity, electron paramagnetic resonance indicated the presence of functional PSII. Difference absorption spectra showed that the cytochrome b559 contained heme. The plastoquinone pool was largely reduced in dark-adapted leaves of the mutant, based on chlorophyll fluorescence and thermoluminescence measurements. We therefore propose that cytochrome b559 plays an important role in PSII by keeping the plastoquinone pool and thereby the acceptor side of PSII oxidized in the dark. Structural alterations as induced by the single Phe → Ser point mutation in the transmembrane domain of PsbF evidently inhibit this function.
AB - The function of cytochrome b559 in photosystem II (PSII) was investigated using a mutant created in tobacco in which the conserved phenylalanine at position 26 in the β-subunit (PsbF) was changed to serine (Bock, R., Kössel, H., and Maliga, P. (1994) EMBO J. 13, 4623-4628). The mutant grew photoautotrophically, but the amount of PSII was reduced and the ultrastructure of the chloroplast was dramatically altered. Very few grana stacks were formed in the mutant. Although isolated PSII-enriched membrane fragments showed low PSII activity, electron paramagnetic resonance indicated the presence of functional PSII. Difference absorption spectra showed that the cytochrome b559 contained heme. The plastoquinone pool was largely reduced in dark-adapted leaves of the mutant, based on chlorophyll fluorescence and thermoluminescence measurements. We therefore propose that cytochrome b559 plays an important role in PSII by keeping the plastoquinone pool and thereby the acceptor side of PSII oxidized in the dark. Structural alterations as induced by the single Phe → Ser point mutation in the transmembrane domain of PsbF evidently inhibit this function.
UR - http://www.scopus.com/inward/record.url?scp=0038644877&partnerID=8YFLogxK
U2 - 10.1074/jbc.M212842200
DO - 10.1074/jbc.M212842200
M3 - Article
C2 - 12571242
AN - SCOPUS:0038644877
SN - 0021-9258
VL - 278
SP - 13554
EP - 13560
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 15
ER -