2019
DOI: 10.1073/pnas.1910675116
|View full text |Cite
|
Sign up to set email alerts
|

Energetics of the exchangeable quinone, Q B , in Photosystem II

Abstract: Photosystem II (PSII), the light-driven water/plastoquinone photooxidoreductase, is of central importance in the planetary energy cycle. The product of the reaction, plastohydroquinone (PQH2), is released into the membrane from the QB site, where it is formed. A plastoquinone (PQ) from the membrane pool then binds into the QB site. Despite their functional importance, the thermodynamic properties of the PQ in the QB site, QB, in its different redox forms have received relatively little attention. Here we repor… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
2
2
1

Citation Types

1
58
0

Year Published

2020
2020
2023
2023

Publication Types

Select...
8

Relationship

0
8

Authors

Journals

citations
Cited by 60 publications
(59 citation statements)
references
References 53 publications
1
58
0
Order By: Relevance
“…91 On the stroma side, Q A is tightly bound to the D2 protein and acts as a single-electron acceptor, whereas Q B in the D1 protein can accept two electrons and be fully protonated. 92 The charge transfer from Q A to Q B is aided by a non-haem iron midway between them. 93 The formed Q B H 2 departs from the reaction centre and is replenished by the plastoquinone pool in the thylakoid membrane.…”
Section: Water Oxidationmentioning
confidence: 99%
“…91 On the stroma side, Q A is tightly bound to the D2 protein and acts as a single-electron acceptor, whereas Q B in the D1 protein can accept two electrons and be fully protonated. 92 The charge transfer from Q A to Q B is aided by a non-haem iron midway between them. 93 The formed Q B H 2 departs from the reaction centre and is replenished by the plastoquinone pool in the thylakoid membrane.…”
Section: Water Oxidationmentioning
confidence: 99%
“…Pc, plastocyanin; P 700 , the dimer of Chl a molecules in PSI; A 0 , the primary electron acceptor in PSI; PhQ, phylloquinone, a secondary electron acceptor in PSI; F X , a 4Fe-4S cluster, a secondary electron acceptor in PSI; F A and F B , 4Fe-4S clusters, the terminal electron acceptors in PSI; Fd, ferredoxin, the mobile electron acceptor; FNR, ferredoxin/NADP + reductase; PQ, PQ •− , and PQH 2 , plastoquinone, plastosemiquinone, and plastoquinol; FeS, a 2Fe-2S cluster of Rieske protein; f, cytochrome f; b L and b H , the low-and high-potential forms of cytochrome (Continued) FIGURE 1 | Continued b 6 ; c n , the heme covalently bound to cytochrome b 6 ; TyrZ, the redox active tyrosine residue; P 680 , the dimer of Chl a molecules in PSII; Pheo, pheophytin, a primary electron acceptor in PSII; Q A , the tightly bound plastoquinone in PSII, the secondary electron acceptor in PSII; Q B , the loosely bound plastoquinone in PSII, the terminal electron acceptor in PSII; VLP, LP, IP, and HP, the very low-, low-, intermediate-, and high-potential forms of cytochrome b 559 in PSII. The E m -values for PSI cofactors are according to Ptushenko et al (2008), those for b 6 /f complex are according to Alric et al (2005), those for PSII are according to Brinkert et al (2016) and Causmaecker et al (2019), except cytochrome b 559 (Khorobrykh, 2019). Closed circles, components situated in hydrophobic zones; open circles, water bulk phases exposed components.…”
Section: Photosystem Imentioning
confidence: 99%
“…In contrast to Q A , Q B undergoes two sequential reduction steps, meaning that Q B − lives for a longer time waiting for the second electron. However, Q B − is thermodynamically stable due to the positive E m potentials (Causmaecker et al, 2019).…”
Section: Photosystem IImentioning
confidence: 99%
“…The fluorescence decay in the formate-treated S268A strain following a single actinic flash was also somewhat slowed relative to control cells (Fig. 4C) but this could be due to the presence of elevated Q À B in dark-adapted centers in the S268A mutant, as the decay of Q À B back to Q B can take up to hours [35,36]. The altered kinetics following the first and second turnovers ( Fig.…”
Section: Discussionmentioning
confidence: 91%