Nature Communications,19 June,2024,DOI：https://doi.org/10.1038/s41467-024-49532-2

Structural basis for an early stage of the photosystem II repair cycle in Chlamydomonas reinhardtii

Anjie Li,Tingting You,Xiaojie Pang,Yidi Wang,Lijin Tian,Xiaobo Li & Zhenfeng Liu

Abstract

Photosystem II (PSII) catalyzes water oxidation and plastoquinone reduction by utilizing light energy. It is highly susceptible to photodamage under high-light conditions and the damaged PSII needs to be restored through a process known as the PSII repair cycle. The detailed molecular mechanism underlying the PSII repair process remains mostly elusive. Here,we report biochemical and structural features of a PSII-repair intermediate complex,likely arrested at an early stage of the PSII repair process in the green alga Chlamydomonas reinhardtii. The complex contains three protein factors associated with a damaged PSII core,namely Thylakoid Enriched Factor 14 (TEF14),Photosystem II Repair Factor 1 (PRF1),and Photosystem II Repair Factor 2 (PRF2). TEF14,PRF1 and PRF2 may facilitate the release of the manganese-stabilizing protein PsbO,disassembly of peripheral light-harvesting complexes from PSII and blockage of the Q_B site,respectively. Moreover,an α-tocopherol quinone molecule is located adjacent to the heme group of cytochrome b₅₅₉,potentially fulfilling a photoprotective role by preventing the generation of reactive oxygen species.

文章链接：https://www.nature.com/articles/s41467-024-49532-2

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