Cryo-EM and femtosecond spectroscopic studies provide mechanistic insight into the energy transfer in CpcL-phycobilisomes

Lvqin Zheng; Zhengdong Zhang; Hongrui Wang; Zhenggao Zheng; Jiayu Wang; Heyuan Liu; Hailong Chen; Chunxia Dong; Guopeng Wang; Yuxiang Weng; Ning Gao; Jindong Zhao

doi:10.1038/s41467-023-39689-7

Cryo-EM and femtosecond spectroscopic studies provide mechanistic insight into the energy transfer in CpcL-phycobilisomes

Nat Commun. 2023 Jul 5;14(1):3961. doi: 10.1038/s41467-023-39689-7.

Authors

Lvqin Zheng^#^{1

2}, Zhengdong Zhang^#^{1

3}, Hongrui Wang^#^{1

3}, Zhenggao Zheng^#^{1

3}, Jiayu Wang⁴, Heyuan Liu⁴, Hailong Chen⁴, Chunxia Dong^{1

3}, Guopeng Wang¹, Yuxiang Weng⁵, Ning Gao^{6

7}, Jindong Zhao^{8

9}

Affiliations

¹ School of Life Sciences, Peking University, Beijing, 100871, China.
² State Key Laboratory of Membrane Biology, Peking University, Beijing, 100871, China.
³ State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China.
⁴ Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
⁵ Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China. yxweng@iphy.ac.cn.
⁶ School of Life Sciences, Peking University, Beijing, 100871, China. gaon@pku.edu.cn.
⁷ State Key Laboratory of Membrane Biology, Peking University, Beijing, 100871, China. gaon@pku.edu.cn.
⁸ School of Life Sciences, Peking University, Beijing, 100871, China. jzhao@pku.edu.cn.
⁹ State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China. jzhao@pku.edu.cn.

^# Contributed equally.

Abstract

Phycobilisomes (PBS) are the major light harvesting complexes of photosynthesis in the cyanobacteria and red algae. CpcL-PBS is a type of small PBS in cyanobacteria that transfers energy directly to photosystem I without the core structure. Here we report the cryo-EM structure of the CpcL-PBS from the cyanobacterium Synechocystis sp. PCC 6803 at 2.6-Å resolution. The structure shows the CpcD domain of ferredoxin: NADP⁺ oxidoreductase is located at the distal end of CpcL-PBS, responsible for its attachment to PBS. With the evidence of ultrafast transient absorption and fluorescence spectroscopy, the roles of individual bilins in energy transfer are revealed. The bilin ^1Iβ⁸²₂ located near photosystem I has an enhanced planarity and is the red-bilin responsible for the direct energy transfer to photosystem I.

Publication types

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

MeSH terms

Bacterial Proteins / chemistry
Cryoelectron Microscopy
Energy Transfer
Photosystem I Protein Complex / metabolism
Phycobilisomes* / metabolism
Spectrometry, Fluorescence
Synechocystis* / metabolism

Substances

Phycobilisomes
Photosystem I Protein Complex
Bacterial Proteins