6DHH

RT XFEL structure of Photosystem II 400 microseconds after the second illumination at 2.2 Angstrom resolution

This is a non-PDB format compatible entry.

Summary for 6DHH

• Entry DOI: 10.2210/pdb6dhh/pdb
• Descriptor: Photosystem II protein D1 1, Photosystem II reaction center protein K, Photosystem II reaction center protein L, ... (36 entities in total)
• Functional Keywords: photosystems, transmembrane, room temperature, electron transport, photosynthesis
• Biological source: Thermosynechococcus elongatus (strain BP-1); More
• Total number of polymer chains: 40
• Total formula weight: 730730.66

Authors

Kern, J.,Chatterjee, R.,Young, I.D.,Fuller, F.D.,Lassalle, L.,Ibrahim, M.,Gul, S.,Fransson, T.,Brewster, A.S.,Alonso-Mori, R.,Hussein, R.,Zhang, M.,Douthit, L.,de Lichtenberg, C.,Cheah, M.H.,Shevela, D.,Wersig, J.,Seufert, I.,Sokaras, D.,Pastor, E.,Weninger, C.,Kroll, T.,Sierra, R.G.,Aller, P.,Butryn, A.,Orville, A.M.,Liang, M.,Batyuk, A.,Koglin, J.E.,Carbajo, S.,Boutet, S.,Moriarty, N.W.,Holton, J.M.,Dobbek, H.,Adams, P.D.,Bergmann, U.,Sauter, N.K.,Zouni, A.,Messinger, J.,Yano, J.,Yachandra, V.K. (deposition date: 2018-05-20, release date: 2018-11-21, Last modification date: 2024-11-06)

Primary citation

Kern, J.,Chatterjee, R.,Young, I.D.,Fuller, F.D.,Lassalle, L.,Ibrahim, M.,Gul, S.,Fransson, T.,Brewster, A.S.,Alonso-Mori, R.,Hussein, R.,Zhang, M.,Douthit, L.,de Lichtenberg, C.,Cheah, M.H.,Shevela, D.,Wersig, J.,Seuffert, I.,Sokaras, D.,Pastor, E.,Weninger, C.,Kroll, T.,Sierra, R.G.,Aller, P.,Butryn, A.,Orville, A.M.,Liang, M.,Batyuk, A.,Koglin, J.E.,Carbajo, S.,Boutet, S.,Moriarty, N.W.,Holton, J.M.,Dobbek, H.,Adams, P.D.,Bergmann, U.,Sauter, N.K.,Zouni, A.,Messinger, J.,Yano, J.,Yachandra, V.K.
Structures of the intermediates of Kok's photosynthetic water oxidation clock.
Nature, 563:421-425, 2018

PubMed Abstract: Inspired by the period-four oscillation in flash-induced oxygen evolution of photosystem II discovered by Joliot in 1969, Kok performed additional experiments and proposed a five-state kinetic model for photosynthetic oxygen evolution, known as Kok's S-state clock or cycle. The model comprises four (meta)stable intermediates (S, S, S and S) and one transient S state, which precedes dioxygen formation occurring in a concerted reaction from two water-derived oxygens bound at an oxo-bridged tetra manganese calcium (MnCaO) cluster in the oxygen-evolving complex. This reaction is coupled to the two-step reduction and protonation of the mobile plastoquinone Q at the acceptor side of PSII. Here, using serial femtosecond X-ray crystallography and simultaneous X-ray emission spectroscopy with multi-flash visible laser excitation at room temperature, we visualize all (meta)stable states of Kok's cycle as high-resolution structures (2.04-2.08 Å). In addition, we report structures of two transient states at 150 and 400 µs, revealing notable structural changes including the binding of one additional 'water', Ox, during the S→S state transition. Our results suggest that one water ligand to calcium (W3) is directly involved in substrate delivery. The binding of the additional oxygen Ox in the S state between Ca and Mn1 supports O-O bond formation mechanisms involving O5 as one substrate, where Ox is either the other substrate oxygen or is perfectly positioned to refill the O5 position during O release. Thus, our results exclude peroxo-bond formation in the S state, and the nucleophilic attack of W3 onto W2 is unlikely.

PubMed: 30405241
DOI: 10.1038/s41586-018-0681-2

Experimental method

X-RAY DIFFRACTION (2.2 Å)