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The recent crystallographic structure at 3.0 A resolution of PSII from Thermosynechococcus elongatus has revealed a cavity in the protein which connects the membrane phase to the binding pocket of the secondary plastoquinone Q(B). The cavity may serve as a quinone diffusion pathway. By fluorescence
The cytochrome b6f complex provides the electronic connection between the photosystem I and photosystem II reaction centers of oxygenic photosynthesis and generates a transmembrane electrochemical proton gradient for adenosine triphosphate synthesis. A 3.0 angstrom crystal structure of the dimeric
Plastoquinone (PLQ) acts as an electron carrier between photosystem II (PSII) and the cytochrome b6f complex. To understand how PLQ enters and leaves PSII, here we show results of coarse grained molecular dynamics simulations of PSII embedded in the thylakoid membrane, covering a total simulation
Structures of the cytochrome b(6)f complex obtained from the thermophilic cyanobacterium Mastigocladus laminosus and the green alga Chlamydomonas reinhardtii, whose appearance in evolution is separated by 10(9) years, are almost identical. Two monomers with a molecular weight of 110,000, containing
A native structure of the cytochrome b(6)f complex with improved resolution was obtained from crystals of the complex grown in the presence of divalent cadmium. Two Cd(2+) binding sites with different occupancy were determined: (i) a higher affinity site, Cd1, which bridges His143 of cytochrome f
The thylakoid membrane has a unique lipid composition, consisting mostly of galactolipids. These thylakoid lipids have important roles in photosynthesis. Here, we investigate to what extent these lipids bind specifically to the Photosystem II complex. To this end, we performed coarse-grain MD
In biological water oxidation, a redox-active tyrosine residue (D1-Tyr161 or YZ) mediates electron transfer between the Mn4CaO5 cluster of the oxygen-evolving complex and the charge-separation site of photosystem II (PSII), driving the cluster through progressively
Photosystem II (PSII) of oxygenic photosynthesis captures sunlight to drive the catalytic oxidation of water and the reduction of plastoquinone. Among the several redox-active cofactors that participate in intricate electron transfer pathways there are two tyrosine residues, YZ and
The cytochrome b6 f (cytb6 f ) complex has a central role in oxygenic photosynthesis, linking electron transfer between photosystems I and II and converting solar energy into a transmembrane proton gradient for ATP synthesis1-3. Electron transfer within
NDH-1 is a key component of the cyclic-electron-transfer around photosystem I (PSI CET) pathway, an important antioxidant mechanism for efficient photosynthesis. Here, we report a 3.2-Å-resolution cryo-EM structure of the ferredoxin (Fd)-NDH-1L complex from the cyanobacterium Thermosynechococcus
The structure and function of the cytochrome b6f complex is considered in the context of recent crystal structures of the complex as an eight subunit, 220 kDa symmetric dimeric complex obtained from the thermophilic cyanobacterium, Mastigocladus laminosus, and the green alga, Chlamydomonas
At least two features of the crystal structures of the cytochrome b6f complex from the thermophilic cyanobacterium, Mastigocladus laminosus and a green alga, Chlamydomonas reinhardtii, have implications for the pathways and mechanism of charge (electron/proton) transfer in the complex: (i) The
Crystal structures and their implications for function are described for the energy transducing hetero-oligomeric dimeric cytochrome b6f complex of oxygenic photosynthesis from the thermophilic cyanobacterium, Mastigocladus laminosus, and the green alga, Chlamydomonas reinhardtii. The complex has a