Skip to Main content Skip to Navigation
Journal articles

In vivo electron donation from plastocyanin and cytochrome c 6 to PSI in Synechocystis sp. PCC6803

Abstract : Many cyanobacteria species can use both plastocyanin and cytochrome c6 as lumenal electron carriers to shuttle electrons from the cytochrome b6f to either photosystem I or the respiratory cytochrome c oxidase. In Synechocystis sp. PCC6803 placed in darkness, about 60% of the active PSI centres are bound to a reduced electron donor which is responsible for the fast rereduction of P700 in vivo after a single charge separation. Here, we show that both cytochrome c6 and plastocyanin can bind to PSI in the dark and participate to the fast phase of P700 reduction, but the fraction of pre-bound PSI is smaller in the case of cytochrome c6 than with plastocyanin. Because of the inter-connection of respiration and photosynthesis in cyanobacteria, the inhibition of the cytochrome c oxidase results in the over-reduction of the photosynthetic electron transfer chain in the dark that translates into a lag in the kinetics of P700 oxidation at the onset of light. We show that this is true both with plastocyanin and cytochrome c6, indicating that the partitioning of electron transport between respiration and photosynthesis is regulated in the same way independently of which of the two lumenal electron carriers is present, although the mechanisms of such regulation are yet to be understood.
Document type :
Journal articles
Complete list of metadata
Contributor : HAL Sorbonne Université 5 Gestionnaire Connect in order to contact the contributor
Submitted on : Wednesday, July 7, 2021 - 11:31:34 AM
Last modification on : Sunday, June 26, 2022 - 3:10:46 AM
Long-term archiving on: : Friday, October 8, 2021 - 6:21:17 PM


Viola et al. - 2021 - In vivo ...
Files produced by the author(s)



Stefania Viola, Julien Sellés, Benjamin Bailleul, Pierre Joliot, Francis-André Wollman. In vivo electron donation from plastocyanin and cytochrome c 6 to PSI in Synechocystis sp. PCC6803. Biochimica biophysica acta (BBA) - Bioenergetics, Elsevier, 2021, 1862 (9), pp.148449. ⟨10.1016/j.bbabio.2021.148449⟩. ⟨hal-03280323⟩



Record views


Files downloads