Structural basis for a PSII-FCPII supercomplex that appears brown

July 30, 2019

A clue to the evolution and diversification of photosynthetic organisms

Researchers from Okayama University, Osaka University, RIKEN CSRS, Kyoto University, Hyogo Prefectural University, the National Institute of Basic Biology and Kobe University have succeeded in analyzing the 3D structure of a marine diatom’s Photosystem II–fucoxanthin chlorophyll a/c-binding protein (PSII–FCPII) supercomplex. Using a cryoelectron microscope, researchers were able to reveal the diatom’s unique pigment composition and arrangement, clarifying the mechanism for efficient harvesting and dissipation of solar energy in water and the mechanism by which photosynthetic organisms have evolved light-harvesting proteins in response to different environments.

These results offer an answer to the question of why photosynthetic organisms exhibit a variety of colors and why they can grow in diverse environments. Color differences are part of a survival strategy, and these findings shed light on how brown diatoms use the limited amounts of light energy available in water, providing insights into the evolution and diversity of photosynthetic organisms and important hints for the creation of artificial devices that will be able to efficiently and selectively use the ever-changing amounts of available sun.

Original article
Nature Plants doi:10.1038/s41477-019-0477-x
R. Nagao, K. Kato, T. Suzuki, K. Ifuku, I. Uchiyama, Y. Kashino, N. Dohmae, S. Akimoto, J-R. Shen, N. Miyazaki, F. Akita,
"Structural basis for energy harvesting and dissipation in a diatom PSII-FCPII supercomplex".
Naoshi Dohmae; Unit Leader
Takehiro Suzuki; Senior Technical Scientist
Biomolecular Characterization Unit