8IMI

A1-A2, A3-A4, B'1-B'2, C'1-C'2 cylinder in cyanobacterial phycobilisome from Anthocerotibacter panamensis (Cluster A)

8IMI の概要

• エントリーDOI: 10.2210/pdb8imi/pdb
• EMDBエントリー: 35530 35531 35534 35537 35541 35565
• 分子名称: ApcE, ApcA2, ApcB3, ... (6 entities in total)
• 機能のキーワード: complex, photosynthesis
• 由来する生物種: Anthocerotibacter panamensis; 詳細
• タンパク質・核酸の鎖数: 52
• 化学式量合計: 1009985.79

構造登録者

Wang, C.H.,Yang, C.H.,Wu, H.Y.,Jiang, H.W.,Ho, M.C.,Ho, M.Y. (登録日: 2023-03-07, 公開日: 2023-10-25, 最終更新日: 2024-05-08)

主引用文献

Jiang, H.W.,Wu, H.Y.,Wang, C.H.,Yang, C.H.,Ko, J.T.,Ho, H.C.,Tsai, M.D.,Bryant, D.A.,Li, F.W.,Ho, M.C.,Ho, M.Y.
A structure of the relict phycobilisome from a thylakoid-free cyanobacterium.
Nat Commun, 14:8009-8009, 2023

PubMed Abstract: Phycobilisomes (PBS) are antenna megacomplexes that transfer energy to photosystems II and I in thylakoids. PBS likely evolved from a basic, inefficient form into the predominant hemidiscoidal shape with radiating peripheral rods. However, it has been challenging to test this hypothesis because ancestral species are generally inaccessible. Here we use spectroscopy and cryo-electron microscopy to reveal a structure of a "paddle-shaped" PBS from a thylakoid-free cyanobacterium that likely retains ancestral traits. This PBS lacks rods and specialized ApcD and ApcF subunits, indicating relict characteristics. Other features include linkers connecting two chains of five phycocyanin hexamers (CpcN) and two core subdomains (ApcH), resulting in a paddle-shaped configuration. Energy transfer calculations demonstrate that chains are less efficient than rods. These features may nevertheless have increased light absorption by elongating PBS before multilayered thylakoids with hemidiscoidal PBS evolved. Our results provide insights into the evolution and diversification of light-harvesting strategies before the origin of thylakoids.

PubMed: 38049400
DOI: 10.1038/s41467-023-43646-9

実験手法

ELECTRON MICROSCOPY (2.59 Å)