Structural organization of an intact phycobilisome and its association with photosystem II  

作　　者：Leifu Chang Xianwei Liu Yanbing Li Cui-Cui Liu Fan Yang Jindong Zhao Sen-Fang Sui 

机构地区：[1]State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, China [2]Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China [3]State Key Laboratory of Protein and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China [4]Key Laboratory of Phycology of CAS, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China

出　　处：《Cell Research》2015年第6期726-737,共12页细胞研究（英文版）

摘　　要：Phycobilisomes （PBSs） are light-harvesting antennae that transfer energy to photosynthetic reaction centers in cyanobacteria and red algae. PBSs are supermolecular complexes composed of phycobiliproteins （PBPs） that bear chromophores for energy absorption and linker proteins. Although the structures of some individual components have been determined using crystallography, the three-dimensional structure of an entire PBS complex, which is crit- ical for understanding the energy transfer mechanism, remains unknown. Here, we report the structures of an intact PBS and a PBS in complex with photosystem II （PSII） from Anabaena sp. strain PCC 7120 using single-particle elec- tron microscopy in combination with biochemical and molecular analyses. In the PBS structure, all PBP trimers and the conserved linker protein domains were unambiguously located, and the global distribution of all chromophores was determined. We provide evidence that ApcE and ApcF are critical for the formation of a protrusion at the bot- tom of PBS, which plays an important role in mediating PBS interaction with PSII. Our results provide insights into the molecular architecture of an intact PBS at different assembly levels and provide the basis for understanding how the light energy absorbed by PBS is transferred to PSII.

关 键 词：PHYCOBILISOME PHOTOSYNTHESIS PHYCOBILIPROTEIN electron microscopy 

分 类 号：Q945.11[生物学—植物学] Q949.2