5b66 | pdb_00005b66

Crystal structure analysis of Photosystem II complex

spinqualitylabelsall models 5b66, resolution 1.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5b66 is a 20 chain structure with sequence from Thermostichus vulcanus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: BCR, BCT, CA, CL, CLA, DGD, DMS, FE2, FME, HEC, HEM, HTG, LHG, LMG, LMT, MG, OEX, PHO, PL9, RRX, SQD, UNL Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function PSBA_THEVL D1 (PsbA) and D2 (PsbD) bind P680, the primary electron donor of photosystem II (PSII) as well as electron acceptors. PSII is a light-driven water plastoquinone oxidoreductase, using light energy to abstract electrons from H(2)O, generating a proton gradient subsequently used for ATP formation.[HAMAP-Rule:MF_01379] Publication Abstract from PubMed The oxygen-evolving complex (OEC) forms the heart of photosystem II (PSII) in photosynthesis. The crystal structure of PSII from Thermosynechococcus vulcanus has been reported at a resolution of 1.9 A and at an averaged X-ray dose of 0.43 MGy. The OEC structure is suggested to be partially reduced to Mn(II) by EXAFS and DFT computational studies. Recently, the "radiation-damage-free" structures have been published at 1.95 A resolution using XFEL, but reports continued to appear that the OEC is reduced to the S0-state of the Kok cycle. To elucidate much more precise structure of the OEC, in this study two structures were determined at extremely low X-ray doses of 0.03 and 0.12 MGy using conventional synchrotron radiation source. The results indicated that the X-ray reduction effects on the OEC were very small in the low dose region below 0.12 MGy, that is, a threshold existed for the OEC structural changes caused by X-ray exposure. The OEC structures of the two identical monomers in the crystal were clearly different under the threshold of the radiation dose, although the surrounding polypeptide frameworks of PSII were the same. The assumption that the OECs in the crystal were in the dark-stable S1-state of the Kok cycle should be re-evaluated. Two Different Structures of the Oxygen-Evolving Complex in the Same Polypeptide Frameworks of Photosystem II.,Tanaka A, Fukushima Y, Kamiya N J Am Chem Soc. 2017 Jan 30. doi: 10.1021/jacs.6b09666. PMID:28102667 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cytochrome C 3D structures Photosystem II

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