Psb30 contributes to structurally stabilise the Photosystem II complex in the thermophilic cyanobacterium Thermosynechococcus elongatus.
A deletion mutant that lacks the Psb30 protein, one of the small subunits of Photosystem II, was constructed in a Thermosynechococcus elongatus strain in which the D1 protein is expressed from the psbA(3) gene (WT*). The DeltaPsb30 mutant appears more susceptible to photodamage, has a cytochrome b(559) that is converted into the low potential form, and probably also lacks the PsbY subunit. In the presence of an inhibitor of protein synthesis, the Psb30 lost more rapidly the water oxidation function than the WT* under the high light conditions. These results suggest that Psb30 contributes to structurally and functionally stabilise the Photosystem II complex in preventing the conversion of cytochrome b(559) into the low potential form. Structural reasons for such effects are discussed.
Sugiura
Miwa
M
Cell-Free Science and Technology Research Center, and Venture Business Laboratory, Department of Chemistry, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan. msugiura@chem.sci.ehime-u.ac.jp
Harada
Sayo
S
Manabe
Takashi
T
Hayashi
Hidenori
H
Kashino
Yasuhiro
Y
Boussac
Alain
A
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000502:physiology*; D000458:Cyanobacteria / Q000378:metabolism*; D003573:Cytochrome b Group / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D008027:Light; D008969:Molecular Sequence Data; D045332:Photosystem II Protein Complex / Q000737:chemistry
D001426:Bacterial Proteins; D003573:Cytochrome b Group; D045332:Photosystem II Protein Complex; C019313:cytochrome b559