6W1Q

RT XFEL structure of Photosystem II 50 microseconds after the second illumination at 2.27 Angstrom resolution

This is a non-PDB format compatible entry.

Summary for 6W1Q

• Entry DOI: 10.2210/pdb6w1q/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: water oxidation, membrane protein, light harvesting, electron transfer, photosynthesis
• Biological source: Thermosynechococcus elongatus (strain BP-1); More
• Total number of polymer chains: 40
• Total formula weight: 756992.61

Authors

Ibrahim, M.,Fransson, T.,Chatterjee, R.,Cheah, M.H.,Hussein, R.,Lassalle, L.,Sutherlin, K.D.,Young, I.D.,Fuller, F.D.,Gul, S.,Kim, I.-S.,Simon, P.S.,de Lichtenberg, C.,Chernev, P.,Bogacz, I.,Pham, C.,Orville, A.M.,Saichek, N.,Northen, T.R.,Batyuk, A.,Carbajo, S.,Alonso-Mori, R.,Tono, K.,Owada, S.,Bhowmick, A.,Bolotovski, R.,Mendez, D.,Moriarty, N.W.,Holton, J.M.,Dobbek, H.,Brewster, A.S.,Adams, P.D.,Sauter, N.K.,Bergmann, U.,Zouni, A.,Messinger, J.,Kern, J.,Yachandra, V.K.,Yano, J. (deposition date: 2020-03-04, release date: 2020-05-20, Last modification date: 2023-10-18)

Primary citation

Ibrahim, M.,Fransson, T.,Chatterjee, R.,Cheah, M.H.,Hussein, R.,Lassalle, L.,Sutherlin, K.D.,Young, I.D.,Fuller, F.D.,Gul, S.,Kim, I.S.,Simon, P.S.,de Lichtenberg, C.,Chernev, P.,Bogacz, I.,Pham, C.C.,Orville, A.M.,Saichek, N.,Northen, T.,Batyuk, A.,Carbajo, S.,Alonso-Mori, R.,Tono, K.,Owada, S.,Bhowmick, A.,Bolotovsky, R.,Mendez, D.,Moriarty, N.W.,Holton, J.M.,Dobbek, H.,Brewster, A.S.,Adams, P.D.,Sauter, N.K.,Bergmann, U.,Zouni, A.,Messinger, J.,Kern, J.,Yachandra, V.K.,Yano, J.
Untangling the sequence of events during the S2→ S3transition in photosystem II and implications for the water oxidation mechanism.
Proc.Natl.Acad.Sci.USA, 117:12624-12635, 2020

PubMed Abstract: In oxygenic photosynthesis, light-driven oxidation of water to molecular oxygen is carried out by the oxygen-evolving complex (OEC) in photosystem II (PS II). Recently, we reported the room-temperature structures of PS II in the four (semi)stable S-states, S, S, S, and S, showing that a water molecule is inserted during the S → S transition, as a new bridging O(H)-ligand between Mn1 and Ca. To understand the sequence of events leading to the formation of this last stable intermediate state before O formation, we recorded diffraction and Mn X-ray emission spectroscopy (XES) data at several time points during the S → S transition. At the electron acceptor site, changes due to the two-electron redox chemistry at the quinones, Q and Q, are observed. At the donor site, tyrosine Y and His190 H-bonded to it move by 50 µs after the second flash, and Glu189 moves away from Ca. This is followed by Mn1 and Mn4 moving apart, and the insertion of O(H) at the open coordination site of Mn1. This water, possibly a ligand of Ca, could be supplied via a "water wheel"-like arrangement of five waters next to the OEC that is connected by a large channel to the bulk solvent. XES spectra show that Mn oxidation (τ of ∼350 µs) during the S → S transition mirrors the appearance of O electron density. This indicates that the oxidation state change and the insertion of water as a bridging atom between Mn1 and Ca are highly correlated.

PubMed: 32434915
DOI: 10.1073/pnas.2000529117

Experimental method

X-RAY DIFFRACTION (2.27 Å)