Heterogeneous Composition of Oxygen-Evolving Complexes in Crystal Structures of Dark-Adapted Photosystem II

Biochemistry ◽  
2021 ◽  
Author(s):  
Jimin Wang ◽  
Christopher J. Gisriel ◽  
Krystle Reiss ◽  
Hao-Li Huang ◽  
William H. Armstrong ◽  
...  
Biochemistry ◽  
2015 ◽  
Vol 54 (3) ◽  
pp. 820-825 ◽  
Author(s):  
Leslie Vogt ◽  
Mehmed Z. Ertem ◽  
Rhitankar Pal ◽  
Gary W. Brudvig ◽  
Victor S. Batista

Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.


Biomolecules ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 371
Author(s):  
Koua

The Mn4CaO5 cluster site in the oxygen-evolving complex (OEC) of photosystem II (PSII) undergoes structural perturbations, such as those induced by Ca2+/Sr2+ exchanges or Ca/Mn removal. These changes have been known to induce long-range positive shifts (between +30 and +150 mV) in the redox potential of the primary quinone electron acceptor plastoquinone A (QA), which is located 40 Å from the OEC. To further investigate these effects, we reanalyzed the crystal structure of Sr-PSII resolved at 2.1 Å and compared it with the native Ca-PSII resolved at 1.9 Å. Here, we focus on the acceptor site and report the possible long-range interactions between the donor, Mn4Ca(Sr)O5 cluster, and acceptor sites.


2011 ◽  
Vol 104 (1-2) ◽  
pp. 9-18 ◽  
Author(s):  
Keisuke Kawakami ◽  
Yasufumi Umena ◽  
Nobuo Kamiya ◽  
Jian-Ren Shen

1983 ◽  
Vol 724 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Eric Lam ◽  
Barbara Baltimore ◽  
William Ortiz ◽  
Susan Chollar ◽  
Anastasios Melis ◽  
...  

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