Evidence for Spontaneous Structural Changes in a Dark-Adapted State of Photosystem II

Halverson, Kelly M.; Barry, Bridgette A.

doi:10.1016/s0006-3495(03)74680-3

Cited by 9 publications

(24 citation statements)

References 53 publications

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“…The natural abundance spectrum (Fig. 4A) is similar to S 2 Q B Ϫ -minus-S 1 Q B data reported previously (32,33,(35)(36)(37). Fig.…”

Section: Isotopic Labeling and Structural Changes In Mspsupporting

confidence: 85%

“…When glycerol-containing PSII is illuminated, the multiline form of the S 2 state is generated from the dark-stable S 1 state (26,27 (34 -36). A S 2 Q B Ϫ -minus-S 1 Q B spectrum has also been reported (36,37).…”

Section: Photosystem II (Psii)mentioning

confidence: 74%

“…Whereas many spectral features are in common, when the 200 K and the 277 K spectra are compared, the 200 and 277 K spectra show some dissimilarity in the 1500 -1200 cm Ϫ1 region. The origin of these spectral differences has been discussed previously (35,36). Assignments of the 200 K spectra, based on global isotopic labeling and site-directed mutagenesis, have been described (25,29,47,51).…”

Section: Discussionmentioning

confidence: 99%

“…FT-IR Spectroscopy at 277 K-Infrared spectra at 277 K were recorded on a Bruker (Billerica, MA) IFS-66v/S FT-IR spectrometer equipped with a liquid nitrogen-cooled MCT detector and a Harrick (Ossining, NY) temperature controller (35,36). A Happ-Genzel apodization function and four levels of zero filling were used.…”

Section: Methodsmentioning

confidence: 99%

“…3B may be due to the low amount of label scrambling from Asp to Glu in the [ 13 C]Asp/ Asn-labeled samples (Table I). Infrared Spectroscopy at 277 K-PSII samples, reconstituted with labeled MSP, were irradiated with a single laser flash and examined at 277 K. In these FT-IR experiments, a S 2 Q B Ϫ -minus-S 1 Q B spectrum is acquired (35)(36)(37). The spectra shown in Fig.…”

Section: Isotopic Labeling and Structural Changes In Mspmentioning

confidence: 99%

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Specific Isotopic Labeling and Photooxidation-linked Structural Changes in the Manganese-stabilizing Subunit of Photosystem II

Sachs

Halverson

Barry

2003

Journal of Biological Chemistry

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Photosystem II (PSII) oxidizes water to molecular oxygen; the catalytic site is a cluster of four manganese ions. The catalytic site undergoes four sequential lightdriven oxidation steps to form oxygen; these sequentially oxidized states are referred to as the S n states, where n refers to the number of oxidizing equivalents stored. The extrinsic manganese stabilizing protein (MSP) of PSII influences the efficiency and stability of the manganese cluster, as well as the rates of the S state transitions. To understand how MSP influences photosynthetic water oxidation, we have employed isotope editing and difference Fourier transform infrared spectroscopy. MSP was expressed in Escherichia coli under conditions in which MSP aspartic and glutamic acid residues label at yields of 65 and 41%, respectively. Asparagine and glutamine were also labeled by this approach. GC/MS analysis was consistent with minimal scrambling of label into other amino acid residues and with no significant scrambling into the peptide bond. Selectively labeled MSP was then reconstituted to PSII, which had been stripped of native MSP. Difference Fourier transform infrared spectroscopy was used to probe the S 1 Q A to S 2 Q A ؊ transition at 200 K, as well as the S 1 Q B to S 2 Q B ؊ transition at 277 K. These experiments show that aspargine, glutamine, and glutamate residues in MSP are perturbed by photooxidation of manganese during the S 1 to S 2 transition. Photosystem II (PSII)1 is the multisubunit membrane protein responsible for the light-driven oxidation of water to molecular oxygen in higher plants, algae, and cyanobacteria (1). PSII contains multiple protein subunits, most of which are hydrophobic and traverse the membrane. Intrinsic PSII proteins ligate the antenna and the reaction center chlorophylls, as well as other cofactors that take part in the oxidation/ reduction reactions (2). These intrinsic subunits include the chlorophyll a-binding proteins, CP47 and CP43, the ␣ and ␤ subunits of cytochrome b 559 , and the polypeptides known as D1 and D2. D1 and D2 form the heterodimeric core of PSII (3-5).The catalytic site of the oxygen-evolving complex contains a cluster of four manganese atoms. As water is oxidized, the manganese cluster cycles through five oxidation states, called the S n states (6). Water oxidation is initiated by excitation of the primary chlorophyll donor, P 680 . P 680 * transfers an electron to pheophytin, which in turn reduces a bound plastoquinone, called Q A . Q A Ϫ reduces a second quinone, Q B . Q B acts as a two-electron and two-proton acceptor. On the donor side of PSII, P 680 ϩ oxidizes a redox active tyrosine, Z, which in turn oxidizes the catalytic site. Redox tyrosine Y D and a chlorophyll, Chl Z , are alternate electron donors to P 680 ϩ . Four sequential photooxidations are required for oxygen production (reviewed in Ref. 1).PSII contains several extrinsic subunits, which are bound to the inner lumenal surface of the reaction center (reviewed in Ref. 7). The extrinsic subunits of PSII play key roles in...

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“…The natural abundance spectrum (Fig. 4A) is similar to S 2 Q B Ϫ -minus-S 1 Q B data reported previously (32,33,(35)(36)(37). Fig.…”

Section: Isotopic Labeling and Structural Changes In Mspsupporting

confidence: 85%

Section: Photosystem II (Psii)mentioning

confidence: 74%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Isotopic Labeling and Structural Changes In Mspmentioning

confidence: 99%

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Specific Isotopic Labeling and Photooxidation-linked Structural Changes in the Manganese-stabilizing Subunit of Photosystem II

Sachs

Halverson

Barry

2003

Journal of Biological Chemistry

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Orientational Jahn–Teller Isomerism in the Dark‐Stable State of Nature's Water Oxidase

2021

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The tetramanganese-calcium cluster of the oxygenevolving complex of photosystem II adopts electronically and magnetically distinct but interconvertible valence isomeric forms in its first light-driven oxidized catalytic state,S 2 .T his bistability is implicated in gating the final catalytic states preceding O À Ob ond formation, but it is unknown how the biological system enables its emergence and controls its effect.Here we show that the Mn 4 CaO 5 cluster in the resting (darkstable) S 1 state adopts orientational Jahn-Teller isomeric forms arising from adirectional change in electronic configuration of the "dangler" Mn III ion. The isomers are consistent with available structural data and explain previously unresolved electron paramagnetic resonance spectroscopic observations on the S 1 state.T his unique isomerism in the resting state is shown to be the electronic origin of valence isomerism in the S 2 state,establishing afunctional role of orientational Jahn-Teller isomerism unprecedented in biological or artificial catalysis.

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Orientational Jahn–Teller Isomerism in the Dark‐Stable State of Nature's Water Oxidase

2021

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Evidence for Spontaneous Structural Changes in a Dark-Adapted State of Photosystem II

Cited by 9 publications

References 53 publications

Specific Isotopic Labeling and Photooxidation-linked Structural Changes in the Manganese-stabilizing Subunit of Photosystem II

Specific Isotopic Labeling and Photooxidation-linked Structural Changes in the Manganese-stabilizing Subunit of Photosystem II

Orientational Jahn–Teller Isomerism in the Dark‐Stable State of Nature's Water Oxidase

Orientational Jahn–Teller Isomerism in the Dark‐Stable State of Nature's Water Oxidase

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