6ZZY

Structure of high-light grown Chlorella ohadii photosystem I

6ZZY の概要

• エントリーDOI: 10.2210/pdb6zzy/pdb
• EMDBエントリー: 11589
• 分子名称: Photosystem I P700 chlorophyll a apoprotein A1, Photosystem I reaction center subunit XII, Photosystem I reaction center subunit VIII, ... (52 entities in total)
• 機能のキーワード: photosystem i, light stress, photosynthesis
• 由来する生物種: Chlorella ohadii (Freshwater green alga); 詳細
• タンパク質・核酸の鎖数: 23
• 化学式量合計: 801806.83

構造登録者

Caspy, I.,Nelson, N.,Nechushtai, R.,Shkolnisky, Y.,Neumann, E. (登録日: 2020-08-05, 公開日: 2021-07-28, 最終更新日: 2024-11-06)

主引用文献

Caspy, I.,Neumann, E.,Fadeeva, M.,Liveanu, V.,Savitsky, A.,Frank, A.,Kalisman, Y.L.,Shkolnisky, Y.,Murik, O.,Treves, H.,Hartmann, V.,Nowaczyk, M.M.,Schuhmann, W.,Rogner, M.,Willner, I.,Kaplan, A.,Schuster, G.,Nelson, N.,Lubitz, W.,Nechushtai, R.
Cryo-EM photosystem I structure reveals adaptation mechanisms to extreme high light in Chlorella ohadii.
Nat.Plants, 7:1314-1322, 2021

PubMed Abstract: Photosynthesis in deserts is challenging since it requires fast adaptation to rapid night-to-day changes, that is, from dawn's low light (LL) to extreme high light (HL) intensities during the daytime. To understand these adaptation mechanisms, we purified photosystem I (PSI) from Chlorella ohadii, a green alga that was isolated from a desert soil crust, and identified the essential functional and structural changes that enable the photosystem to perform photosynthesis under extreme high light conditions. The cryo-electron microscopy structures of PSI from cells grown under low light (PSI) and high light (PSI), obtained at 2.70 and 2.71 Å, respectively, show that part of light-harvesting antenna complex I (LHCI) and the core complex subunit (PsaO) are eliminated from PSI to minimize the photodamage. An additional change is in the pigment composition and their number in LHCI; about 50% of chlorophyll b is replaced by chlorophyll a. This leads to higher electron transfer rates in PSI and might enable C. ohadii PSI to act as a natural photosynthesiser in photobiocatalytic systems. PSI or PSI were attached to an electrode and their induced photocurrent was determined. To obtain photocurrents comparable with PSI, 25 times the amount of PSI was required, demonstrating the high efficiency of PSI. Hence, we suggest that C. ohadii PSI is an ideal candidate for the design of desert artificial photobiocatalytic systems.

PubMed: 34462576
DOI: 10.1038/s41477-021-00983-1

実験手法

ELECTRON MICROSCOPY (3.16 Å)