New and unexpected routes for ultrafast electron transfer in photosynthetic reaction centers
8.7 The Structure-Function Relationships of Photosynthetic Reaction Centers
- Environmental Science
Highly oriented photosynthetic reaction centers generate a proton gradient in synthetic protocells
- Biology, ChemistryProceedings of the National Academy of Sciences
It is shown that synthetic protocells, based on giant lipid vesicles embedding an oriented population of reaction centers, are capable of generating a photoinduced proton gradient across the membrane.
Primary electron transfer processes in photosynthetic reaction centers from oxygenic organisms
- Chemistry, PhysicsPhotosynthesis Research
The results suggest that the sequence of the primary electron transfer reactions is P680-→ ChlD1 → PheD1–→ QA →-QA (PS II) and P700-→-A0A/A0B →–A1 a/A1B (PS I), however, alternate routes of charge separation in PS II, under different excitation conditions, are not ruled out.
An evolutionary analysis of the reaction mechanisms of photosystem I reduction by cytochrome c(6) and plastocyanin.
Modified reaction centres oxidize tyrosine in reactions that mirror photosystem II
- Biology, ChemistryNature
Modifications of reaction centres from the purple bacterium Rhodobacter sphaeroides result in the generation of a tyrosyl radical in a manner similar to that of photosystem II, and optical and electron paramagnetic resonance spectra showed changes consistent with oxidation of the tyrosine.
Architecture of the photosynthetic complex from a green sulfur bacterium
An important missing puzzle piece in the understanding of the evolution of RCs is presented: a cryo–electron microscopy structure of the homodimeric type I RC from a green sulfur bacterium bound to a light-harvesting protein.
Primary Processes in Photosynthesis: What do we learn from High-Field EPR Spectroscopy?
Primary photosynthesis is the biological electron transfer process by which green plants and certain bacteria convert the energy of sunlight into electrochemical energy. Light-induced charge…
Photosynthetic Machineries in Nano-Systems
- ChemistryCurrent protein & peptide science
This review will summarize the current status of knowledge, the kinds of applications available and the difficulties to be overcome in the different applications, and show possible research directions for the close future.
Mechanism of Primary Charge Separation in Photosynthetic Reaction Centers
This chapter presents a review of primary charge separation processes in various photosynthetic reaction centers. Common motif of the known reaction centers is briefly discussed, followed by a…
SHOWING 1-10 OF 32 REFERENCES
Photophysics of photosynthesis. Structure and spectroscopy of reaction centers of purple bacteria
A new pathway for transmembrane electron transfer in photosynthetic reaction centers of Rhodobacter sphaeroides not involving the excited special pair.
- Physics, ChemistryBiochemistry
The results provide for the first time clear evidence that excitation of the monomeric bacteriochlorophyll in the active branch of the reaction center (B(A)) drives ultrafast transmembrane electron transfer without the involvement of P*, demonstrating a new and efficient mechanism for solar energy transduction in photosynthesis.
Structure and function of bacterial photosynthetic reaction centres
The primary reaction of photosynthesis is light-driven charge separation, carried out in reaction centres, which are complexes of integral membrane proteins and cofactors. The recent determination of…
Light-induced structural changes in photosynthetic reaction center: implications for mechanism of electron-proton transfer.
High resolution x-ray diffraction data from crystals of the Rhodobacter sphaeroides photosynthetic reaction center have been collected at cryogenic temperature in the dark and under illumination, and the structures were refined at 2.2 and 2.6 angstrom resolution to explain the observed kinetics of electron transfer.
A model for the photosystem II reaction center core including the structure of the primary donor P680.
This work has modeled important parts of the D1 and D2 proteins on the basis of the crystallographic structure of the reaction center from Rhodopseudomonas viridis, and applied techniques from computational chemistry that incorporate statistical data on side-chain rotameric states from known protein structure and that describe interactions within the model using an empirical potential energy function.
Electron transfer in the heliobacterial reaction center: evidence against a quinone-type electron acceptor functioning analogous to A1 in photosystem I.
- Physics, ChemistryBiochimica et biophysica acta
Photosystem I at 4 Å resolution represents the first structural model of a joint photosynthetic reaction centre and core antenna system
- ChemistryNature Structural Biology
The architecture of the protein core indicates quinone and iron-sulphur type reaction centres to have a common ancestor and suggests a dual role for these Chl a both in excitation energy and electron transfer.
Investigation into the source of electron transfer asymmetry in bacterial reaction centers.
The results suggest that asymmetry in the charge distribution of the excited BChl dimer (P*) in wild-type RCs contributes only modestly to the directionality of electron transfer and differential orbital overlap of the two BChls of P with the chromophores on the L and M polypeptides does not contribute substantially to preferential electron transfer to BPhL.
Proton transfer in reaction centers from photosynthetic bacteria.
- Chemistry, PhysicsAnnual review of biochemistry
Several possible mechanisms for proton transfer are consistent with the observed experimental results and proposed proton pathways and involve proton transfers from individual amino acid residues or internal water molecules either as single steps or in a concerted fashion.
A metalloradical mechanism for the generation of oxygen from water in photosynthesis.
A model is proposed whereby the tyrosyl radical functions by abstracting hydrogen atoms from substrate water bound as terminal ligands to two of the four manganese ions, establishing clear analogies between photosynthetic water oxidation and amino acid radical function in other enzymatic reactions.