dc.contributor.author
Viola, Stefania
dc.contributor.author
Roseby, William
dc.contributor.author
Santabarbara, Stefano
dc.contributor.author
Nürnberg, Dennis
dc.contributor.author
Assunção, Ricardo
dc.contributor.author
Dau, Holger
dc.contributor.author
Sellés, Julien
dc.contributor.author
Boussac, Alain
dc.contributor.author
Fantuzzi, Andrea
dc.contributor.author
Rutherford, A. William
dc.date.accessioned
2023-01-19T11:45:11Z
dc.date.available
2023-01-19T11:45:11Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/37708
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-37423
dc.description.abstract
Photosystem II (PSII) uses the energy from red light to split water and reduce quinone, an energy-demanding process based on chlorophyll a (Chl-a) photochemistry. Two types of cyanobacterial PSII can use chlorophyll d (Chl-d) and chlorophyll f (Chl-f) to perform the same reactions using lower energy, far-red light. PSII from Acaryochloris marina has Chl-d replacing all but one of its 35 Chl-a, while PSII from Chroococcidiopsis thermalis, a facultative far-red species, has just 4 Chl-f and 1 Chl-d and 30 Chl-a. From bioenergetic considerations, the far-red PSII were predicted to lose photochemical efficiency and/or resilience to photodamage. Here, we compare enzyme turnover efficiency, forward electron transfer, back-reactions and photodamage in Chl-f-PSII, Chl-d-PSII, and Chl-a-PSII. We show that: (i) all types of PSII have a comparable efficiency in enzyme turnover; (ii) the modified energy gaps on the acceptor side of Chl-d-PSII favour recombination via PD1+Phe- repopulation, leading to increased singlet oxygen production and greater sensitivity to high-light damage compared to Chl-a-PSII and Chl-f-PSII; (iii) the acceptor-side energy gaps in Chl-f-PSII are tuned to avoid harmful back reactions, favouring resilience to photodamage over efficiency of light usage. The results are explained by the differences in the redox tuning of the electron transfer cofactors Phe and QA and in the number and layout of the chlorophylls that share the excitation energy with the primary electron donor. PSII has adapted to lower energy in two distinct ways, each appropriate for its specific environment but with different functional penalties.
en
dc.format.extent
40 Seiten
dc.rights.uri
https://creativecommons.org/licenses/by/4.0/
dc.subject
photosystem II
en
dc.subject
cyanobacteria
en
dc.subject
photochemistry
en
dc.subject.ddc
500 Naturwissenschaften und Mathematik::530 Physik::530 Physik
dc.title
Impact of energy limitations on function and resilience in long-wavelength Photosystem II
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation.articlenumber
e79890
dcterms.bibliographicCitation.doi
10.7554/eLife.79890
dcterms.bibliographicCitation.journaltitle
eLife
dcterms.bibliographicCitation.volume
11
dcterms.bibliographicCitation.url
https://doi.org/10.7554/eLife.79890
refubium.affiliation
Physik
refubium.resourceType.isindependentpub
no
dcterms.accessRights.openaire
open access
dcterms.isPartOf.eissn
2050-084X
refubium.resourceType.provider
WoS-Alert