The extrinsic proteins of photosystem II: structure, function and evolution

2014 Fiscal Year Final Research Report

• Project/Area Number: 24370025
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: Tokyo University of Science
• Principal Investigator: TOMO Tatsuya 東京理科大学, 理学部, 教授 (60300886)
• Co-Investigator(Kenkyū-buntansha): NOGUCHI Takumi 名古屋大学, 理学(系)研究科, 教授 (60241246) ; MINO Hiroyuki 名古屋大学, 理学(系)研究科, 准教授 (70300902)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 光化学 / 酸素発生 / 多様性

Outline of Final Research Achievements

The photosynthetic alga has a highly diverse in species. The extrinsic proteins of photosystem II (PS II) are also rich in diversity. To clarify the role of extrinsic proteins, we successfully isolated PS II complex from cyanobacteria, red alga, diatom and Symbiodinium. Our analyses showed the PsbO and PsbV affect the secondary structure of core subunits of PS II by Fourier transform infrared spectroscopy. PS II isolated from red alga, which is primitive red alga, contained fourth extrinsic proteins, PsbQ′, which role had not been elucidated yet. We did the measurements of redox potential of secondary electron transfer component of PS II (QA) to find out the role of this subunit. We observed the positive potential shit of QA after reconstitution of PsbQ’ to cyanobacterial PS II. This result indicates the role of QA reduces the yield of the triplet chlorophyll by direct charge recombination. As a result, this leads to the decrease of singlet oxygen in the red alga.

Free Research Field

光合成