TY - JOUR
T1 - Validating the predictions of murburn model for oxygenic photosynthesis: Analyses of ligand-binding to protein complexes and cross-system comparisons
T2 - Analyses of ligand-binding to protein complexes and cross-system comparisons
AU - Manoj, Kelath Murali
AU - Gideon, Daniel Andrew
AU - Parashar, Abhinav
AU - Nirusimhan, Vijay
AU - Annadurai, Pushparaj
AU - Jacob, Vivian David
AU - Manekkathodi, Afsal
N1 - Publisher Copyright:
© 2021 Informa UK Limited, trading as Taylor & Francis Group.
PY - 2022
Y1 - 2022
N2 - In this second half of our treatise on oxygenic photosynthesis, we provide support for the murburn model of the light reaction of photosynthesis and ratify key predictions made in the first part. Molecular docking and visualization of various ligands of quinones/quinols (and their derivatives) with PS II/Cytochrome b 6 f complexes did not support chartered 2e-transport role of quinols. A broad variety of herbicides did not show any affinity/binding-based rationales for inhibition of photosynthesis. We substantiate the proposal that disubstituted phenolics (perceived as protonophores/uncouplers or affinity-based inhibitors in the classical purview) serve as interfacial modulators of diffusible reactive (oxygen) species or DR(O)S. The DRS-based murburn model is evidenced by the identification of multiple ADP-binding sites on the extra-membraneous projection of protein complexes and structure/distribution of the photo/redox catalysts. With a panoramic comparison of the redox metabolic machinery across diverse organellar/cellular systems, we highlight the ubiquitous one-electron murburn facets (cofactors of porphyrin, flavin, FeS, other metal centers and photo/redox active pigments) that enable a facile harnessing of the utility of DRS. In the summative analyses, it is demonstrated that the murburn model of light reaction explains the structures of membrane supercomplexes recently observed in thylakoids and also accounts for several photodynamic experimental observations and evolutionary considerations. In toto, the work provides a new orientation and impetus to photosynthesis research. Communicated by Ramaswamy H. Sarma.
AB - In this second half of our treatise on oxygenic photosynthesis, we provide support for the murburn model of the light reaction of photosynthesis and ratify key predictions made in the first part. Molecular docking and visualization of various ligands of quinones/quinols (and their derivatives) with PS II/Cytochrome b 6 f complexes did not support chartered 2e-transport role of quinols. A broad variety of herbicides did not show any affinity/binding-based rationales for inhibition of photosynthesis. We substantiate the proposal that disubstituted phenolics (perceived as protonophores/uncouplers or affinity-based inhibitors in the classical purview) serve as interfacial modulators of diffusible reactive (oxygen) species or DR(O)S. The DRS-based murburn model is evidenced by the identification of multiple ADP-binding sites on the extra-membraneous projection of protein complexes and structure/distribution of the photo/redox catalysts. With a panoramic comparison of the redox metabolic machinery across diverse organellar/cellular systems, we highlight the ubiquitous one-electron murburn facets (cofactors of porphyrin, flavin, FeS, other metal centers and photo/redox active pigments) that enable a facile harnessing of the utility of DRS. In the summative analyses, it is demonstrated that the murburn model of light reaction explains the structures of membrane supercomplexes recently observed in thylakoids and also accounts for several photodynamic experimental observations and evolutionary considerations. In toto, the work provides a new orientation and impetus to photosynthesis research. Communicated by Ramaswamy H. Sarma.
KW - diffusible reactive species (DRS)
KW - disubstituted phenolics
KW - light reaction of photosynthesis
KW - murburn concept
KW - photophosphorylation
KW - uncoupling
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U2 - 10.1080/07391102.2021.1953607
DO - 10.1080/07391102.2021.1953607
M3 - Article
C2 - 34328391
SN - 0739-1102
VL - 40
SP - 11024
EP - 11056
JO - Journal of Biomolecular Structure and Dynamics
JF - Journal of Biomolecular Structure and Dynamics
IS - 21
ER -