7COU

Structure of cyanobacterial photosystem II in the dark S1 state

Summary for 7COU

• Entry DOI: 10.2210/pdb7cou/pdb
• Descriptor: Photosystem II protein D1, Photosystem II reaction center protein K, Photosystem II reaction center protein L, ... (40 entities in total)
• Functional Keywords: photosystem ii, photosynthesis
• Biological source: Thermosynechococcus vulcanus; More
• Total number of polymer chains: 39
• Total formula weight: 723667.66

Authors

Li, H.,Shen, J.-R.,Suga, M. (deposition date: 2020-08-05, release date: 2021-04-28, Last modification date: 2023-11-29)

Primary citation

Li, H.,Nakajima, Y.,Nomura, T.,Sugahara, M.,Yonekura, S.,Chan, S.K.,Nakane, T.,Yamane, T.,Umena, Y.,Suzuki, M.,Masuda, T.,Motomura, T.,Naitow, H.,Matsuura, Y.,Kimura, T.,Tono, K.,Owada, S.,Joti, Y.,Tanaka, R.,Nango, E.,Akita, F.,Kubo, M.,Iwata, S.,Shen, J.R.,Suga, M.
Capturing structural changes of the S 1 to S 2 transition of photosystem II using time-resolved serial femtosecond crystallography.
Iucrj, 8:431-443, 2021

PubMed Abstract: Photosystem II (PSII) catalyzes light-induced water oxidation through an S -state cycle, leading to the generation of di-oxygen, protons and electrons. Pump-probe time-resolved serial femtosecond crystallography (TR-SFX) has been used to capture structural dynamics of light-sensitive proteins. In this approach, it is crucial to avoid light contamination in the samples when analyzing a particular reaction intermediate. Here, a method for determining a condition that avoids light contamination of the PSII microcrystals while minimizing sample consumption in TR-SFX is described. By swapping the pump and probe pulses with a very short delay between them, the structural changes that occur during the S-to-S transition were examined and a boundary of the excitation region was accurately determined. With the sample flow rate and concomitant illumination conditions determined, the S-state structure of PSII could be analyzed at room temperature, revealing the structural changes that occur during the S-to-S transition at ambient temperature. Though the structure of the manganese cluster was similar to previous studies, the behaviors of the water molecules in the two channels (O1 and O4 channels) were found to be different. By comparing with the previous studies performed at low temperature or with a different delay time, the possible channels for water inlet and structural changes important for the water-splitting reaction were revealed.

PubMed: 33953929
DOI: 10.1107/S2052252521002177

Experimental method

X-RAY DIFFRACTION (2.25 Å)