Allophycocyanin A is a carbon dioxide receptor in the cyanobacterial phycobilisome

Guillen-Garcia, A.; Gibson, S.; Jordan, C.; Ramaswamy, V.; Linthwaite, V.; Bromley, E.H.C.; Brown, A.P.; Hodgson, D.; Blower, T.; Verlet, J.; Degiacomi, M.; Palsson, L-O.; Cann, M.J.

Abstract

Light harvesting is fundamental for production of ATP and reducing equivalents for CO2 fixation during photosynthesis. However, electronic energy transfer (EET) through a photosystem can harm the photosynthetic apparatus when not balanced with CO2. Here, we show that CO2 binding to the light-harvesting complex modulates EET in photosynthetic cyanobacteria. More specifically, CO2 binding to the allophycocyanin alpha subunit of the light-harvesting complex regulates EET and its fluorescence quantum yield in the cyanobacterium Synechocystis sp. PCC 6803. CO2 binding decreases the inter-chromophore distance in the allophycocyanin trimer. The result is enhanced EET in vitro and in live cells. Our work identifies a direct target for CO2 in the cyanobacterial light-harvesting apparatus and provides insights into photosynthesis regulation.

Citation

Guillen-Garcia, A., Gibson, S., Jordan, C., Ramaswamy, V., Linthwaite, V., Bromley, E., …Cann, M. (2022). Allophycocyanin A is a carbon dioxide receptor in the cyanobacterial phycobilisome. Nature Communications, 13, Article 5289. https://doi.org/10.1038/s41467-022-32925-6

• Journal Article Type: Article
• Acceptance Date: Aug 24, 2022
• Online Publication Date: Sep 8, 2022
• Publication Date: 2022
• Deposit Date: Feb 28, 2022
• Publicly Available Date: Sep 9, 2022
• Journal: Nature Communications
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Article Number: 5289
• DOI: https://doi.org/10.1038/s41467-022-32925-6
• Public URL: https://durham-repository.worktribe.com/output/1212939