Modulation of Electron Transfer Branches by Atrazine and Triazine Herbicides in Photosynthetic Reaction Centers.
Biochemistry
; 63(9): 1206-1213, 2024 05 07.
Article
em En
| MEDLINE
| ID: mdl-38587893
ABSTRACT
Quinone analogue molecules, functioning as herbicides, bind to the secondary quinone site, QB, 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 (Em) values of the primary quinone (QA) in these crystal structures. However, a slight Em difference at the bacteriopheophytin in the electron transfer inactive branch (HM) 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 QB-mediated link between the electron transfer inactive HM and the proton uptake pathway in PbRCs.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Atrazina
/
Triazinas
/
Complexo de Proteínas do Centro de Reação Fotossintética
/
Herbicidas
Idioma:
En
Revista:
Biochemistry
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Japão