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Modulation of Electron Transfer Branches by Atrazine and Triazine Herbicides in Photosynthetic Reaction Centers.
- Source :
-
Biochemistry [Biochemistry] 2024 May 07; Vol. 63 (9), pp. 1206-1213. Date of Electronic Publication: 2024 Apr 08. - Publication Year :
- 2024
-
Abstract
- Quinone analogue molecules, functioning as herbicides, bind to the secondary quinone site, Q <subscript>B</subscript> , in type-II photosynthetic reaction centers, including those from purple bacteria (PbRC). Here, we investigated the impact of herbicide binding on electron transfer branches, using herbicide-bound PbRC crystal structures and employing the linear Poisson-Boltzmann equation. In contrast to urea and phenolic herbicides [Fufezan, C. Biochemistry 2005, 44, 12780-12789], binding of atrazine and triazine did not cause significant changes in the redox-potential ( E <subscript>m</subscript> ) values of the primary quinone (Q <subscript>A</subscript> ) in these crystal structures. However, a slight E <subscript>m</subscript> difference at the bacteriopheophytin in the electron transfer inactive branch (H <subscript>M</subscript> ) was observed between the S (-)- and R (+)-triazine-bound PbRC structures. This discrepancy is linked to variations in the protonation pattern of the tightly coupled Glu-L212 and Glu-H177 pairs, crucial components of the proton uptake pathway in native PbRC. These findings suggest the existence of a Q <subscript>B</subscript> -mediated link between the electron transfer inactive H <subscript>M</subscript> and the proton uptake pathway in PbRCs.
- Subjects :
- Electron Transport
Oxidation-Reduction
Models, Molecular
Rhodobacter sphaeroides metabolism
Crystallography, X-Ray
Herbicides chemistry
Herbicides metabolism
Atrazine chemistry
Atrazine metabolism
Triazines chemistry
Triazines metabolism
Photosynthetic Reaction Center Complex Proteins metabolism
Photosynthetic Reaction Center Complex Proteins chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 1520-4995
- Volume :
- 63
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- Biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 38587893
- Full Text :
- https://doi.org/10.1021/acs.biochem.4c00010