7pi0 | pdb_00007pi0

Unstacked compact Dunaliella PSII

spinqualitylabelsall models 7pi0, resolution 2.43Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7pi0 is a 20 chain structure with sequence from Dunaliella salina. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 2.43Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function D0FY01_DUNSA This b-type cytochrome is tightly associated with the reaction center of photosystem II (PSII). PSII is a light-driven water:plastoquinone oxidoreductase that uses light energy to abstract electrons from H(2)O, generating O(2) and a proton gradient subsequently used for ATP formation. It consists of a core antenna complex that captures photons, and an electron transfer chain that converts photonic excitation into a charge separation.[HAMAP-Rule:MF_00642][RuleBase:RU004529] Publication Abstract from PubMed Photosystem II (PSII) generates an oxidant whose redox potential is high enough to enable water oxidation , a substrate so abundant that it assures a practically unlimited electron source for life on earth . Our knowledge on the mechanism of water photooxidation was greatly advanced by high-resolution structures of prokaryotic PSII . Here, we show high-resolution cryogenic electron microscopy (cryo-EM) structures of eukaryotic PSII from the green alga Dunaliella salina at two distinct conformations. The conformers are also present in stacked PSII, exhibiting flexibility that may be relevant to the grana formation in chloroplasts of the green lineage. CP29, one of PSII associated light-harvesting antennae, plays a major role in distinguishing the two conformations of the supercomplex. We also show that the stacked PSII dimer, a form suggested to support the organisation of thylakoid membranes , can appear in many different orientations providing a flexible stacking mechanism for the arrangement of grana stacks in thylakoids. Our findings provide a structural basis for the heterogenous nature of the eukaryotic PSII on multiple levels. Structure of Dunaliella photosystem II reveals conformational flexibility of stacked and unstacked supercomplexes.,Caspy I, Fadeeva M, Mazor Y, Nelson N Elife. 2023 Feb 17;12:e81150. doi: 10.7554/eLife.81150. PMID:36799903 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Photosystem II 3D structures

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