Distant electrostatic interactions modulate the free energy level of QA- in the photosynthetic reaction center

Biochemistry
J MiksovskaP Sebban

Abstract

In the reaction centers from the purple photosynthetic bacterium Rhodobacter capsulatus, we have determined that residue L212Glu, situated near the secondary quinone acceptor QB, modulates the free energy level of the reduced primary quinone molecule QA- at high pH. Even though the distance between L212Glu and QA is 17 A, our results indicate an apparent interaction energy between them of 30 +/- 18 meV. This interaction was measured by quantitating the stoichiometry of partial proton uptake upon formation of QA- as a function of pH in four mutant strains which lack L212Glu, in comparison with the wild type. These strains are the photosynthetically incompetent site-specific mutants L212Glu -->Gln and L212Glu-L213Asp-->Ala-Ala and the photocompetent strains L212Glu-->Ala and L212Ala-L213Ala-M43Asn-->Ala-Ala-Asp. Below pH 7.5, the stoichiometry of proton uptake from all strains is nearly superimposable with that of the wild type. However, at variance with the wild type, reaction centers from all strains that lack L212Glu fail to take up protons above pH 9. The lack of a change in the free energy level of QA- at high pH in the L212Glu-modified strains is confirmed by the determination of the pH dependence of the rate (kAP) of P+QA-...Continue Reading

References

Jan 1, 1992·Annual Review of Biochemistry·M Y Okamura, G Feher
May 1, 1995·Acta Crystallographica. Section D, Biological Crystallography·B ArnouxF Reiss-Husson

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Citations

Aug 17, 2005·Biochemistry·Jennifer Madeo, M R Gunner
Mar 18, 2008·Nature Structural & Molecular Biology·Shangwei HouToshinori Hoshi
Mar 9, 2002·Photochemistry and Photobiology·Julia TandoriPierre Sebban
Sep 30, 1998·Proceedings of the National Academy of Sciences of the United States of America·M S GraigeM Y Okamura
May 2, 2002·Proceedings of the National Academy of Sciences of the United States of America·J TandoriL Baciou
Dec 10, 1999·Proceedings of the National Academy of Sciences of the United States of America·J MiksovskaP Sebban
Nov 15, 2000·Proceedings of the National Academy of Sciences of the United States of America·P AdelrothM Y Okamura
Jan 22, 2015·Biophysical Journal·László GerencsérPéter Maróti
Jul 28, 2009·Biochimica Et Biophysica Acta·Hélène CheapPierre Sebban
May 17, 2000·Biochimica Et Biophysica Acta·M Y OkamuraG Feher
Apr 22, 2004·Biochimica Et Biophysica Acta·Pia Adelroth, Peter Brzezinski
May 17, 2000·Biochimica Et Biophysica Acta·S Brandsburg-ZabaryM Gutman
Oct 26, 2016·Journal of Photochemistry and Photobiology. B, Biology·Eugeny P LukashevVladimir Z Paschenko
Jul 25, 2021·Proceedings of the National Academy of Sciences of the United States of America·Yu SugoHiroshi Ishikita

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