The acceptor quinone complex of Rhodopseudomonas viridis reaction centers

Shopes, Robert J.; Wraight, Colin A.

doi:10.1016/0005-2728(85)90242-7

Cited by 108 publications

(81 citation statements)

References 29 publications

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“…This indeed may explain the experimental results, if Fe'+ is the source of the temperature effect on the spectra of PR. Although there is no firm proof that the spin state of Fe'+ does not change when the primary quinone is doubly reduced, addition of o-phenanthroline to the RCs, blocking the electron transfer step between QA and QB [26], does not affect our experimental results. Butler et al [27] (iii) Q-acts as a carrier of spin transitions between the high-spin Q-Fe'+ and P+I-.…”

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confidence: 72%

The relation between the electron spin polarization of the donor triplet state of the photosynthetic reaction center fromRhodopseudomonas viridisand the redox state of the primary acceptor

1986

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The relation between the electron spin polarization of the donor triplet state of the photosynthetic reaction center from Rhodopseudomonas viridis and the redox state of the primary acceptor The hypothesis [( 1986) Photobiochem. Photobiophys. 11,95 -1001 that the temperature dependence of the electron spin polarization (ESP) pattern of the Am = k 1 EPR spectrum of the triplet state PR of the Rhodopseudomonas viridis reaction center is caused by magnetic interaction between the reduced menaquinoneiron complex Q-Fe*+ and the electron spin on I-(reduced bacteriopheophytin b), which is part of the radical pair P+I-(P' is the oxidized primary electron donor P960) has been investigated. It was found that the AEAEAE ESP pattern of the EPR spectrum detected at T> 20 K changes into the usual AEEAAE pattern, when Q-Fe*+ is photochemically converted into Q*-Fez+. This demonstrates that the presence of Q-in Q-Fe*+ is a necessary condition to obtain the AEAEAE ESP pattern.

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confidence: 72%

The relation between the electron spin polarization of the donor triplet state of the photosynthetic reaction center fromRhodopseudomonas viridisand the redox state of the primary acceptor

1986

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“…1 mM sodium ascorbate was added to reduce the reaction center associated high-potential cytochromes c-558, which function as efficient electron donors to photo-oxidized P960 at room temperature [ 13,141. The 10 Hz, 950 nm actinic laser pulses converted the reaction centers to the P!%O-Qi redox state [15] and data collection started after a delay of at least 1.5 s.…”

Section: Methodsmentioning

confidence: 99%

Sub‐picosecond measurements of primary electron transfer inRhodopseudomonas viridisreaction centers using near‐infrared excitation

Wasielewski

Tiede

1986

FEBS Letters

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“…sphaeroides, but mostly from an intrinsic difference in the protein portion of the reaction centers that lowers further the midpoint potential of QA/QAin Rps. viridis (Shopes and Wraight, 1985).…”

Section: Biophysical Analyses-differencesmentioning

confidence: 99%

Expression of a higher plant psbA gene in Synechocystis 6803 yields a functional hybrid photosystem II reaction center complex.

1991

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The psbA gene codes for the D1 polypeptide of the photosystem I 1 reaction center complex and is found in a11 photosynthetic organisms that carry out oxygenic photosynthesis. Here we describe the construction and characterization of a strain of the cyanobacterium Synechocystis sp PCC 6803 in which the three endogenous psbA genes are replaced by a single psbA gene from the chloroplast genome of the higher plant Poa annua. The resulting chimeric strain, KWPAS, grows photoautotrophically with a doubling time of 26 hours compared with 20 hours for wild-type Synechocystis 6803. The mutant oxidizes water to oxygen at light-saturated rates comparable with wild type, despite differences in 15% of the primary structure of D1 between these species. RNA gel blot analysis indicates the presence in KWPAS of a psbA transcript of approximately 1.25 kilobases, consistent with the chloroplast promoter also acting as a promoter in Synechocystis. By using antibodies specific for the carboxyl-terminal extension of the D1 polypeptide of higher plants, we showed that the D1 polypeptide synthesized by KWPAS is posttranslationally modified at the carboxyl terminus, probably through processing. A detailed biophysical analysis of the chimeric photosystem I 1 complex indicated that the rates of forward electron transfer are similar to wild type. The rates of charge recombination between the donor and acceptor sides of the reaction center are, however, accelerated by as much as a factor of nine (QA-to S p ) and are the most likely explanation for the lower rate of photoautotrophic growth in the mutant. We conclude that the psbA gene from a higher plant can be expressed in cyanobacteria and its product processed and assembled into a functional chimeric photosystem I 1 reaction center.

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The acceptor quinone complex of Rhodopseudomonas viridis reaction centers

Cited by 108 publications

References 29 publications

The relation between the electron spin polarization of the donor triplet state of the photosynthetic reaction center fromRhodopseudomonas viridisand the redox state of the primary acceptor

The relation between the electron spin polarization of the donor triplet state of the photosynthetic reaction center fromRhodopseudomonas viridisand the redox state of the primary acceptor

Sub‐picosecond measurements of primary electron transfer inRhodopseudomonas viridisreaction centers using near‐infrared excitation

Expression of a higher plant psbA gene in Synechocystis 6803 yields a functional hybrid photosystem II reaction center complex.

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