Requirement of carotene isomerization for the assembly of photosystem II in Synechocystis sp. PCC 6803.
Carotene isomerase mutant (crtH mutant) cells of Synechocystis sp. PCC 6803 can accumulate beta-carotene under light conditions. However, the mutant cells grown under a light-activated heterotrophic growth condition contained detectable levels of neither beta-carotene nor D1 protein of the photosystem (PS) II reaction center, and no oxygen-evolving activity of PSII was detected. beta-Carotene and D1 protein appeared and a high level of PSII activity was detected after the cells were transferred to a continuous light condition. The PSI activities of thylakoid membranes from mutant cells were almost the same as those of thylakoid membranes from wild-type cells, both before and after transfer to the continuous light condition. These results suggest that beta-carotene is required for the assembly of PSII but not for that of PSI.
Masamoto
Kazumori
K
Biological Laboratory, Faculty of Education, Kumamoto University, Kurokami 2-40-1, Kumamoto, 860-8555 Japan. masamoto@gpo.kumamoto-u.ac.jp
Hisatomi
Shin-ichiro
S
Sakurai
Isamu
I
Gombos
Zoltán
Z
Wada
Hajime
H
D002338:Carotenoids / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D007536:Isomerism; D045332:Photosystem II Protein Complex / Q000737:chemistry*; D013057:Spectrum Analysis; D046939:Synechocystis / Q000737:chemistry*
D045332:Photosystem II Protein Complex; D002338:Carotenoids