Light Adaptation in Phycobilisome Antennas: Influence on the Rod Length and Structural Arrangement

Phycobilisomes, the light-harvesting antennas of cyanobacteria, can adapt to a wide range of environments thanks to a composition and function response to stress conditions. We study how structural changes influence excitation transfer in these supercomplexes. Specifically, we show the influence of...

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Bibliographic Details
Main Authors: Keren, Nir, Paltiel, Yossi, Nevo, Reinat, Reich, Ziv, Chenu, Aurelia, Cao, Jianshu
Other Authors: Massachusetts Institute of Technology. Department of Chemistry
Format: Article
Published: American Chemical Society (ACS) 2018
Online Access:http://hdl.handle.net/1721.1/118370
https://orcid.org/0000-0001-7616-7809
Description
Summary:Phycobilisomes, the light-harvesting antennas of cyanobacteria, can adapt to a wide range of environments thanks to a composition and function response to stress conditions. We study how structural changes influence excitation transfer in these supercomplexes. Specifically, we show the influence of the rod length on the photon absorption and subsequent excitation transport to the core. Despite the fact that the efficiency of individual disks on the rod decreases with increasing rod length, we find an optimal length for which the average rod efficiency is maximal. Combining this study with experimental structural measurements, we propose models for the arrangement of the phycobiliproteins inside the thylakoid membranes, evaluate the importance of rod length, and predict the corresponding transport properties for different cyanobacterial species. This analysis, which links the functional and structural properties of full phycobilisome complexes, thus provides further rationales to help resolve their exact structure.