Structural and functional properties of different types of siphonous LHCII trimers from an intertidal green alga Bryopsis corticulans

Zhenhua Li; Cuicui Zhou; Songhao Zhao; Jinyang Zhang; Xueyang Liu; Min Sang; Xiaochun Qin; Yanyan Yang; Guangye Han; Tingyun Kuang; Jian-Ren Shen; Wenda Wang

doi:10.1016/j.str.2023.08.001

Structural and functional properties of different types of siphonous LHCII trimers from an intertidal green alga Bryopsis corticulans

Structure. 2023 Oct 5;31(10):1247-1258.e3. doi: 10.1016/j.str.2023.08.001. Epub 2023 Aug 25.

Authors

Zhenhua Li¹, Cuicui Zhou¹, Songhao Zhao¹, Jinyang Zhang¹, Xueyang Liu¹, Min Sang², Xiaochun Qin³, Yanyan Yang⁴, Guangye Han⁴, Tingyun Kuang⁴, Jian-Ren Shen⁵, Wenda Wang⁶

Affiliations

¹ Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Science, Yuquan Road, Shijingshan District, Beijing 100049, China.
² China National Botanical Garden, Beijing 100093, China.
³ School of Biological Science and Technology, University of Jinan, Jinan 250022, China.
⁴ Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China.
⁵ Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China; Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan. Electronic address: [email protected].
⁶ Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China. Electronic address: [email protected].

PMID: 37633266
DOI: 10.1016/j.str.2023.08.001

Abstract

Light-harvesting complexes of photosystem II (LHCIIs) in green algae and plants are vital antenna apparatus for light harvesting, energy transfer, and photoprotection. Here we determined the structure of a siphonous-type LHCII trimer from the intertidal green alga Bryopsis corticulans by X-ray crystallography and cryo-electron microscopy (cryo-EM), and analyzed its functional properties by spectral analysis. The Bryopsis LHCII (Bry-LHCII) structures in both homotrimeric and heterotrimeric form show that green light-absorbing siphonaxanthin and siphonein occupied the sites of lutein and violaxanthin in plant LHCII, and two extra chlorophylls (Chls) b replaced Chls a. Binding of these pigments expands the blue-green light absorption of B. corticulans in the tidal zone. We observed differences between the Bry-LHCII homotrimer crystal and cryo-EM structures, and also between Bry-LHCII homotrimer and heterotrimer cryo-EM structures. These conformational changes may reflect the flexibility of Bry-LHCII, which may be required to adapt to light fluctuations from tidal rhythms.

Keywords: LHCII; crystal and cryo-EM structures; green light harvesting; siphonaxanthin; siphonous green algae.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Chlorophyta* / metabolism
Cryoelectron Microscopy
Light-Harvesting Protein Complexes* / chemistry
Light-Harvesting Protein Complexes* / metabolism
Photosystem II Protein Complex / chemistry
Photosystem II Protein Complex / metabolism
Thylakoids

Substances

Light-Harvesting Protein Complexes
Photosystem II Protein Complex