Detection of the water-binding sites of the oxygen-evolving complex of photosystem II using W-band 17O electron-electron double resonance-detected NMR spectroscopy

Leonid Rapatskiy; Nicholas Cox; Anton Savitsky; William M. Ames; Julia Sander; Marc M. Nowaczyk; Matthias Rögner; Alain Boussac; Frank Neese; Johannes Messinger; Wolfgang Lubitz

doi:10.1021/ja3053267

Detection of the water-binding sites of the oxygen-evolving complex of photosystem II using W-band ¹⁷O electron-electron double resonance-detected NMR spectroscopy

Leonid Rapatskiy, Nicholas Cox^*, Anton Savitsky, William M. Ames, Julia Sander, Marc M. Nowaczyk, Matthias Rögner, Alain Boussac, Frank Neese, Johannes Messinger, Wolfgang Lubitz

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

247 Citations (Scopus)

Abstract

Water binding to the Mn₄O₅Ca cluster of the oxygen-evolving complex (OEC) of Photosystem II (PSII) poised in the S ₂ state was studied via H₂¹⁷O- and ²H₂O-labeling and high-field electron paramagnetic resonance (EPR) spectroscopy. Hyperfine couplings of coordinating ¹⁷O (I = ⁵/₂) nuclei were detected using W-band (94 GHz) electron-electron double resonance (ELDOR) detected NMR and Davies/Mims electron-nuclear double resonance (ENDOR) techniques. Universal ¹⁵N (I = ¹/₂) labeling was employed to clearly discriminate the ¹⁷O hyperfine couplings that overlap with ¹⁴N (I = 1) signals from the D1-His332 ligand of the OEC (StichBiochemistry 2011, 50 (34), 7390-7404). Three classes of ¹⁷O nuclei were identified: (i) one μ-oxo bridge; (ii) a terminal Mn-OH/OH₂ ligand; and (iii) Mn/Ca-H₂O ligand(s). These assignments are based on ¹⁷O model complex data, on comparison to the recent 1.9 Å resolution PSII crystal structure (UmenaNature 2011, 473, 55-60), on NH₃ perturbation of the ¹⁷O signal envelope and density functional theory calculations. The relative orientation of the putative ¹⁷O μ-oxo bridge hyperfine tensor to the ¹⁴N(¹⁵N) hyperfine tensor of the D1-His332 ligand suggests that the exchangeable μ-oxo bridge links the outer Mn to the Mn₃O₃Ca open-cuboidal unit (O4 and O5 in the Umena et al. structure). Comparison to literature data favors the Ca-linked O5 oxygen over the alternative assignment to O4. All ¹⁷O signals were seen even after very short (≥15 s) incubations in H₂ ¹⁷O suggesting that all exchange sites identified could represent bound substrate in the S₁ state including the μ-oxo bridge. ¹H/²H (I = ¹/₂, 1) ENDOR data performed at Q- (34 GHz) and W-bands complement the above findings. The relatively small ¹H/²H couplings observed require that all the μ-oxo bridges of the Mn₄O₅Ca cluster are deprotonated in the S₂ state. Together, these results further limit the possible substrate water-binding sites and modes within the OEC. This information restricts the number of possible reaction pathways for O-O bond formation, supporting an oxo/oxyl coupling mechanism in S₄.

Original language	English
Pages (from-to)	16619-16634
Number of pages	16
Journal	Journal of the American Chemical Society
Volume	134
Issue number	40
DOIs	https://doi.org/10.1021/ja3053267
Publication status	Published - 10 Oct 2012
Externally published	Yes

Access to Document

10.1021/ja3053267

Cite this

Rapatskiy, L., Cox, N., Savitsky, A., Ames, W. M., Sander, J., Nowaczyk, M. M., Rögner, M., Boussac, A., Neese, F., Messinger, J., & Lubitz, W. (2012). Detection of the water-binding sites of the oxygen-evolving complex of photosystem II using W-band ¹⁷O electron-electron double resonance-detected NMR spectroscopy. Journal of the American Chemical Society, 134(40), 16619-16634. https://doi.org/10.1021/ja3053267

@article{0be172311db24158b885d41cbd877073,

title = "Detection of the water-binding sites of the oxygen-evolving complex of photosystem II using W-band 17O electron-electron double resonance-detected NMR spectroscopy",

abstract = "Water binding to the Mn4O5Ca cluster of the oxygen-evolving complex (OEC) of Photosystem II (PSII) poised in the S 2 state was studied via H217O- and 2H2O-labeling and high-field electron paramagnetic resonance (EPR) spectroscopy. Hyperfine couplings of coordinating 17O (I = 5/2) nuclei were detected using W-band (94 GHz) electron-electron double resonance (ELDOR) detected NMR and Davies/Mims electron-nuclear double resonance (ENDOR) techniques. Universal 15N (I = 1/2) labeling was employed to clearly discriminate the 17O hyperfine couplings that overlap with 14N (I = 1) signals from the D1-His332 ligand of the OEC (StichBiochemistry 2011, 50 (34), 7390-7404). Three classes of 17O nuclei were identified: (i) one μ-oxo bridge; (ii) a terminal Mn-OH/OH2 ligand; and (iii) Mn/Ca-H2O ligand(s). These assignments are based on 17O model complex data, on comparison to the recent 1.9 {\AA} resolution PSII crystal structure (UmenaNature 2011, 473, 55-60), on NH3 perturbation of the 17O signal envelope and density functional theory calculations. The relative orientation of the putative 17O μ-oxo bridge hyperfine tensor to the 14N(15N) hyperfine tensor of the D1-His332 ligand suggests that the exchangeable μ-oxo bridge links the outer Mn to the Mn3O3Ca open-cuboidal unit (O4 and O5 in the Umena et al. structure). Comparison to literature data favors the Ca-linked O5 oxygen over the alternative assignment to O4. All 17O signals were seen even after very short (≥15 s) incubations in H2 17O suggesting that all exchange sites identified could represent bound substrate in the S1 state including the μ-oxo bridge. 1H/2H (I = 1/2, 1) ENDOR data performed at Q- (34 GHz) and W-bands complement the above findings. The relatively small 1H/2H couplings observed require that all the μ-oxo bridges of the Mn4O5Ca cluster are deprotonated in the S2 state. Together, these results further limit the possible substrate water-binding sites and modes within the OEC. This information restricts the number of possible reaction pathways for O-O bond formation, supporting an oxo/oxyl coupling mechanism in S4.",

author = "Leonid Rapatskiy and Nicholas Cox and Anton Savitsky and Ames, {William M.} and Julia Sander and Nowaczyk, {Marc M.} and Matthias R{\"o}gner and Alain Boussac and Frank Neese and Johannes Messinger and Wolfgang Lubitz",

year = "2012",

month = oct,

day = "10",

doi = "10.1021/ja3053267",

language = "English",

volume = "134",

pages = "16619--16634",

journal = "Journal of the American Chemical Society",

issn = "0002-7863",

publisher = "American Chemical Society",

number = "40",

}

Rapatskiy, L, Cox, N, Savitsky, A, Ames, WM, Sander, J, Nowaczyk, MM, Rögner, M, Boussac, A, Neese, F, Messinger, J & Lubitz, W 2012, 'Detection of the water-binding sites of the oxygen-evolving complex of photosystem II using W-band ¹⁷O electron-electron double resonance-detected NMR spectroscopy', Journal of the American Chemical Society, vol. 134, no. 40, pp. 16619-16634. https://doi.org/10.1021/ja3053267

Detection of the water-binding sites of the oxygen-evolving complex of photosystem II using W-band ¹⁷O electron-electron double resonance-detected NMR spectroscopy. / Rapatskiy, Leonid; Cox, Nicholas; Savitsky, Anton et al.
In: Journal of the American Chemical Society, Vol. 134, No. 40, 10.10.2012, p. 16619-16634.

Research output: Contribution to journal › Article › peer-review

TY - JOUR

T1 - Detection of the water-binding sites of the oxygen-evolving complex of photosystem II using W-band 17O electron-electron double resonance-detected NMR spectroscopy

AU - Rapatskiy, Leonid

AU - Cox, Nicholas

AU - Savitsky, Anton

AU - Ames, William M.

AU - Sander, Julia

AU - Nowaczyk, Marc M.

AU - Rögner, Matthias

AU - Boussac, Alain

AU - Neese, Frank

AU - Messinger, Johannes

AU - Lubitz, Wolfgang

PY - 2012/10/10

Y1 - 2012/10/10

N2 - Water binding to the Mn4O5Ca cluster of the oxygen-evolving complex (OEC) of Photosystem II (PSII) poised in the S 2 state was studied via H217O- and 2H2O-labeling and high-field electron paramagnetic resonance (EPR) spectroscopy. Hyperfine couplings of coordinating 17O (I = 5/2) nuclei were detected using W-band (94 GHz) electron-electron double resonance (ELDOR) detected NMR and Davies/Mims electron-nuclear double resonance (ENDOR) techniques. Universal 15N (I = 1/2) labeling was employed to clearly discriminate the 17O hyperfine couplings that overlap with 14N (I = 1) signals from the D1-His332 ligand of the OEC (StichBiochemistry 2011, 50 (34), 7390-7404). Three classes of 17O nuclei were identified: (i) one μ-oxo bridge; (ii) a terminal Mn-OH/OH2 ligand; and (iii) Mn/Ca-H2O ligand(s). These assignments are based on 17O model complex data, on comparison to the recent 1.9 Å resolution PSII crystal structure (UmenaNature 2011, 473, 55-60), on NH3 perturbation of the 17O signal envelope and density functional theory calculations. The relative orientation of the putative 17O μ-oxo bridge hyperfine tensor to the 14N(15N) hyperfine tensor of the D1-His332 ligand suggests that the exchangeable μ-oxo bridge links the outer Mn to the Mn3O3Ca open-cuboidal unit (O4 and O5 in the Umena et al. structure). Comparison to literature data favors the Ca-linked O5 oxygen over the alternative assignment to O4. All 17O signals were seen even after very short (≥15 s) incubations in H2 17O suggesting that all exchange sites identified could represent bound substrate in the S1 state including the μ-oxo bridge. 1H/2H (I = 1/2, 1) ENDOR data performed at Q- (34 GHz) and W-bands complement the above findings. The relatively small 1H/2H couplings observed require that all the μ-oxo bridges of the Mn4O5Ca cluster are deprotonated in the S2 state. Together, these results further limit the possible substrate water-binding sites and modes within the OEC. This information restricts the number of possible reaction pathways for O-O bond formation, supporting an oxo/oxyl coupling mechanism in S4.

AB - Water binding to the Mn4O5Ca cluster of the oxygen-evolving complex (OEC) of Photosystem II (PSII) poised in the S 2 state was studied via H217O- and 2H2O-labeling and high-field electron paramagnetic resonance (EPR) spectroscopy. Hyperfine couplings of coordinating 17O (I = 5/2) nuclei were detected using W-band (94 GHz) electron-electron double resonance (ELDOR) detected NMR and Davies/Mims electron-nuclear double resonance (ENDOR) techniques. Universal 15N (I = 1/2) labeling was employed to clearly discriminate the 17O hyperfine couplings that overlap with 14N (I = 1) signals from the D1-His332 ligand of the OEC (StichBiochemistry 2011, 50 (34), 7390-7404). Three classes of 17O nuclei were identified: (i) one μ-oxo bridge; (ii) a terminal Mn-OH/OH2 ligand; and (iii) Mn/Ca-H2O ligand(s). These assignments are based on 17O model complex data, on comparison to the recent 1.9 Å resolution PSII crystal structure (UmenaNature 2011, 473, 55-60), on NH3 perturbation of the 17O signal envelope and density functional theory calculations. The relative orientation of the putative 17O μ-oxo bridge hyperfine tensor to the 14N(15N) hyperfine tensor of the D1-His332 ligand suggests that the exchangeable μ-oxo bridge links the outer Mn to the Mn3O3Ca open-cuboidal unit (O4 and O5 in the Umena et al. structure). Comparison to literature data favors the Ca-linked O5 oxygen over the alternative assignment to O4. All 17O signals were seen even after very short (≥15 s) incubations in H2 17O suggesting that all exchange sites identified could represent bound substrate in the S1 state including the μ-oxo bridge. 1H/2H (I = 1/2, 1) ENDOR data performed at Q- (34 GHz) and W-bands complement the above findings. The relatively small 1H/2H couplings observed require that all the μ-oxo bridges of the Mn4O5Ca cluster are deprotonated in the S2 state. Together, these results further limit the possible substrate water-binding sites and modes within the OEC. This information restricts the number of possible reaction pathways for O-O bond formation, supporting an oxo/oxyl coupling mechanism in S4.

UR - http://www.scopus.com/inward/record.url?scp=84867341468&partnerID=8YFLogxK

U2 - 10.1021/ja3053267

DO - 10.1021/ja3053267

M3 - Article

SN - 0002-7863

VL - 134

SP - 16619

EP - 16634

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

IS - 40

ER -

Detection of the water-binding sites of the oxygen-evolving complex of photosystem II using W-band ¹⁷O electron-electron double resonance-detected NMR spectroscopy

Abstract

Access to Document

Other files and links

Fingerprint

Cite this