Project A4

Tracking protonation dynamics in photosynthetic water oxidation in wild-type and mutated photosystem II

Principal Investigator: Prof. Dr. Holger Dau (FU)

Photosynthetic water oxidation and O2-formation by plants, algae and cyanobacteria has shaped biosphere and atmosphere. The goal of this project is to understand the pivotal role of protonation dynamics in the redox chemistry of photosynthetic water oxidation. In classical and novel biophysical experiments, the functionally relevant proton movements are tracked with microsecond resolution, with a focus on time-resolved infrared spectroscopy. Moreover, the cyanobacterial photosystem II is genetically modified and, in a collaborative effort, structurally characterized by protein crystallography. The step toward atomistic understanding is approached jointly with the theory projects of the SFB.

Publications 2014 - 2017

Bommer, M., Bondar, A.-N., Zouni, A., Dobbek, H., and Dau, H. (2016). Crystallographic and computational analysis of the barrel part of the PsbO protein of photosystem II - carboxylate-water clusters as putative proton transfer relays and structural switches. Biochemistry 55, 4626-4635.

Chernev, P., Zaharieva, I., Rossini, E., Galstyan, A., Dau, H., and Knapp, E.-W. (2016). Merging structural information from X-ray crystallography, quantum chemistry and EXAFS spectra: The oxygen-evolving complex in PSII. Journal of Physical Chemistry B 120, 10899-10922.

Damrow, R., Maldener, I., and Zilliges, Y. (2016).The Multiple Functions of Common Microbial Carbon Polymers, Glycogen and PHB, during Stress Responses in the Non-Diazotrophic Cyanobacterium Synechocystis sp. PCC 6803. Frontiers in  Microbiology 7, 966.

Karge, O., Bondar, A.-N., and Dau, H. (2014). Cationic screening of charged surface groups (carboxylates) affects electron transfer steps in photosystem-II water oxidation and quinone reduction. Biochimica et Biophysica Acta (BBA) - Bioenergetics 1837, 1625-1634.

Klauss, A., Haumann, M., and Dau, H. (2015). Seven steps of alternating electron and proton transfer in photosystem II water oxidation traced by time-resolved photothermal beam deflection at improved sensitivity. J Phys Chem B 119, 2677-2689.

Zaharieva, I., Chernev, P., Berggren, G., Anderlund, M., Styring, S., Dau, H., and Haumann, M. (2016). Room-temperature energy-sampling K-beta X-ray emission spectroscopy of the Mn4Ca complex of photosynthesis reveals three manganese-centered oxidation steps and suggests a coordination change prior to O2 formation. Biochemistry 55, 4197-4211.

Zaharieva, I., González-Flores, D., Asfari, B., Pasquini, C., Mohammadi, M.R., Klingan, K., Zizak, I., Loos, S., Chernev, P., and Dau, H. (2016). Water oxidation catalysis – role of redox and structural dynamics in biological photosynthesis and inorganic manganese oxides. Energy Environ Sci 9, 2433-2443.

Zhang, C., Chen, C., Dong, H., Shen, J.-R., Dau, H., and Zhao, J. (2015). A synthetic Mn4Ca-cluster mimicking the oxygen-evolving center of photosynthesis. Science 348, 690-693.

Zilliges, Y. and Dau, H. (2016). Unexpected capacity for organic carbon assimilation by Thermosynechococcus elongatus, a crucial photosynthetic model organism. FEBS Letters 590, 962-970.