Hydrogen Bonding, Solvent Exchange, and Coupled Proton and Electron Transfer in the Oxidation and Reduction of Redox-Active Tyrosine YZin Mn-Depleted Core Complexes of Photosystem II†

Biochemistry ◽  
1998 ◽  
Vol 37 (51) ◽  
pp. 17931-17943 ◽  
Author(s):  
Bruce A. Diner ◽  
Dee Ann Force ◽  
David W. Randall ◽  
R. David Britt
2008 ◽  
Vol 389 (5) ◽  
Author(s):  
Bernhard Loll ◽  
Matthias Broser ◽  
Peter B. Kós ◽  
Jan Kern ◽  
Jacek Biesiadka ◽  
...  

Abstract In the cyanobacterium Thermosynechococcus elongatus BP-1, living in hot springs, the light environment directly regulates expression of genes that encode key components of the photosynthetic multi-subunit protein-pigment complex photosystem II (PSII). Light is not only essential as an energy source to power photosynthesis, but leads to formation of aggressive radicals which induce severe damage of protein subunits and organic cofactors. Photosynthetic organisms develop several protection mechanisms against this photo-damage, such as the differential expression of genes coding for the reaction center subunit D1 in PSII. Testing the expression of the three different genes (psbAI, psbAII, psbAIII) coding for D1 in T. elongatus under culture conditions used for preparing the material used in crystallization of PSII showed that under these conditions only subunit PsbA1 is present. However, exposure to high-light intensity induced partial replacement of PsbA1 with PsbA3. Modeling of the variant amino acids of the three different D1 copies in the 3.0 Å resolution crystal structure of PSII revealed that most of them are in the direct vicinity to redox-active cofactors of the electron transfer chain. Possible structural and mechanistic consequences for electron transfer are discussed.


2019 ◽  
Vol 21 (17) ◽  
pp. 8721-8728 ◽  
Author(s):  
Jun Chai ◽  
Zhaoyang Zheng ◽  
Hui Pan ◽  
Shengbai Zhang ◽  
K. V. Lakshmi ◽  
...  

All quantum-mechanical calculations provide insights into the effect of the hydrogen bonding network on the proton-coupled electron transfer at YZ and YD in photosystem II.


Biochemistry ◽  
1998 ◽  
Vol 37 (30) ◽  
pp. 10547-10554 ◽  
Author(s):  
Catherine Berthomieu ◽  
Rainer Hienerwadel ◽  
Alain Boussac ◽  
Jacques Breton ◽  
Bruce A. Diner

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