Structural basis for blue-green light harvesting and energy dissipation in diatoms

• DOI: 10.1126/science.aav0365
• Publication Date: 2019-02-08T00:09:23Z
• Authors: Wenda Wang; Long-Jiang Yu; Caizhe Xu; Takashi Tomizaki; Songhao Zhao; Yasufumi Umena; Xiaobo Chen; Xiaochun Qin; Yueyong Xin; Michihiro Suga; Guangye Han; Tingyun Kuang; Jian-Ren Shen
• Keywords: Chlorophyll; Diatoms; 0303 health sciences; Light; Chlorophyll A; Xanthophylls; Thylakoids; 7. Clean energy; 03 medical and health sciences; Energy Transfer; 14. Life underwater; Chlorophyll Binding Proteins; Photosynthesis; Protein Structure, Quaternary

All the hues, even the blues

Photosynthetic organisms must balance maximizing productive light absorption and protecting themselves from too much light, which causes damage. Both tasks require pigments—chlorophylls and carotenoids—which absorb light energy and either transfer it to photosystems or disperse it as heat. Wang et al. determined the structure of a fucoxanthin chlorophyll a/c–binding protein (FCP) from a diatom. The structure reveals the arrangement of the specialized photosynthetic pigments in this light-harvesting protein. Fucoxanthin and chlorophyll c absorb the blue-green light that penetrates to deeper water and is not absorbed well by chlorophylls a or b. FCPs are related to the light-harvesting complexes of plants but have more binding sites for carotenoids and fewer for chlorophylls, which may help transfer and disperse light energy.

Science , this issue p. eaav0365