Cryo-EM and femtosecond spectroscopic studies provide mechanistic insight into the energy transfer in CpcL-phycobilisomes
- Resource Type
- Original Paper
- Authors
- Zheng, Lvqin; Zhang, Zhengdong; Wang, Hongrui; Zheng, Zhenggao; Wang, Jiayu; Liu, Heyuan; Chen, Hailong; Dong, Chunxia; Wang, Guopeng; Weng, Yuxiang; Gao, Ning; Zhao, Jindong
- Source
- Nature Communications. 14(1)
- Subject
- Language
- English
- ISSN
- 2041-1723
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.
CpcL-phycobilisome (PBS) is a type of small PBS that transfers energy directly to photosystem I (PSI) without a core structure. Here the authors combine cryo-electron microscopy and ultrafast spectroscopy to explore energy transfer pathway in CpcL-PBS.