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Optically detected magnetic resonance and mutational analysis reveal significant differences in the photochemistry and structure of chlorophyll f synthase and photosystem II
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SYSNO ASEP 0583746 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Optically detected magnetic resonance and mutational analysis reveal significant differences in the photochemistry and structure of chlorophyll f synthase and photosystem II Author(s) Agostini, Alessandro (BC-A) RID, ORCID
Shen, G. (US)
Bryant, D. A. (US)
Golbeck, J. H. (US)
van der Est, A. (CA)
Carbonera, D. (IT)Number of authors 6 Article number 149002 Source Title Biochimica Et Biophysica Acta-Bioenergetics. - : Elsevier - ISSN 0005-2728
Roč. 1864, č. 4 (2023)Number of pages 9 s. Language eng - English Country NL - Netherlands Keywords time-resolved epr ; triplet-states ; antenna complex ; primary donor ; oxygen ; core ; photosynthesis ; spectrum ; odmr ; d1 ; Chlorophyll f ; Opticaly detected magnetic resonance ; Triplet state ; Type-II photosystem Subject RIV BO - Biophysics OECD category Biophysics R&D Projects EF18_053/0016982 GA MŠMT - Ministry of Education, Youth and Sports (MEYS) Method of publishing Open access Institutional support BC-A - RVO:60077344 UT WOS 001102522300001 EID SCOPUS 85167832912 DOI 10.1016/j.bbabio.2023.149002 Annotation In cyanobacteria that undergo far red light photoacclimation (FaRLiP), chlorophyll (Chl) f is produced by the ChlF synthase enzyme, probably by photo-oxidation of Chl a. The enzyme forms homodimeric complexes and the primary amino acid sequence of ChlF shows a high degree of homology with the D1 subunit of photosystem II (PSII). However, few details of the photochemistry of ChlF are known. The results of a mutational analysis and optically detected magnetic resonance (ODMR) data from ChlF are presented. Both sets of data show that there are significant differences in the photochemistry of ChlF and PSII. Mutation of residues that would disrupt the donor side primary electron transfer pathway in PSII do not inhibit the production of Chl f, while alteration of the putative ChlZ, P680 and QA binding sites rendered ChlF non-functional. Together with previously published transient EPR and flash photolysis data, the ODMR data show that in untreated ChlF samples, the triplet state of P680 formed by intersystem crossing is the primary species generated by light excitation. This is in contrast to PSII, in which 3P680 is only formed by charge recombination when the quinone acceptors are removed or chemically reduced. The triplet states of a carotenoid (3Car) and a small amount of 3Chl f are also observed by ODMR. The polarization pattern of 3Car is consistent with its formation by triplet energy transfer from ChlZ if the carotenoid molecule is rotated by 15 degrees about its long axis compared to the orientation in PSII. It is proposed that the singlet oxygen formed by the interaction between molecular oxygen and 3P680 might be involved in the oxidation of Chl a to Chl f. Workplace Biology Centre (since 2006) Contact Dana Hypšová, eje@eje.cz, Tel.: 387 775 214 Year of Publishing 2024 Electronic address https://www.sciencedirect.com/science/article/pii/S0005272823000488?via%3Dihub
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