4q54

Serial Time-resolved crystallography of Photosystem II using a femtosecond X-ray laser The S state after two flashes(S3)

spinqualitylabelsall models 4q54, resolution 5.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4q54 is a 38 chain structure with sequence from Thermosynechococcus elongatus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: BCR, BCT, CA, CL, CLA, DGD, FE2, HEM, LHG, MG, OEX, PHO, PL9, SQD Related: 3arc, 2axt Activity: Photosystem II, with EC number 1.10.3.9 Resources: FirstGlance, OCA, RCSB, PDBsum Function [PSBF_THEEB] This b-type cytochrome is tightly associated with the reaction center of photosystem II and possibly is part of the water-oxidation complex (By similarity).[HAMAP-Rule:MF_00643] [PSBL_THEEB] Required for PSII activity (By similarity). [PSBJ_THEEB] This protein is a component of the reaction center of photosystem II (By similarity). [YCF12_THEEB] A core subunit of photosystem II (PSII).[HAMAP-Rule:MF_01329] [PSBU_THEEB] Stabilizes the structure of photosystem II oxygen-evolving complex (OEC), the ion environment of oxygen evolution and protects the OEC against heat-induced inactivation (By similarity).[HAMAP-Rule:MF_00589] [PSBT_THEEB] Seems to play a role in the dimerization of PSII. [PSBI_THEEB] This protein is a component of the reaction center of photosystem II.[HAMAP-Rule:MF_01316] [PSBA1_THEEB] This is one of the two reaction center proteins of photosystem II. [PSBX_THEEB] Involved in the binding and/or turnover of quinones at the Q(B) site of Photosystem II. [PSBZ_THEEB] Controls the interaction of photosystem II (PSII) cores with the light-harvesting antenna. May also aid in binding of PsbK, Ycf12 and the oxygen-evolving complex to PSII, at least in vitro. [PSBK_THEEB] This protein is a component of the reaction center of photosystem II.[HAMAP-Rule:MF_00441] [PSBO_THEEB] MSP binds to a putative Mn-binding protein and keeps 2 of the 4 Mn-atoms associated with PSII (By similarity). [CY550_THEEB] Low-potential cytochrome c that plays a role in the oxygen-evolving complex of photosystem II. It is not essential for growth under normal conditions but is required under low CO(2) concentrations.[HAMAP-Rule:MF_01378] [PSBE_THEEB] This b-type cytochrome is tightly associated with the reaction center of photosystem II and possibly is part of the water-oxidation complex.[HAMAP-Rule:MF_00642] Publication Abstract from PubMed Photosynthesis, a process catalysed by plants, algae and cyanobacteria converts sunlight to energy thus sustaining all higher life on Earth. Two large membrane protein complexes, photosystem I and II (PSI and PSII), act in series to catalyse the light-driven reactions in photosynthesis. PSII catalyses the light-driven water splitting process, which maintains the Earth's oxygenic atmosphere. In this process, the oxygen-evolving complex (OEC) of PSII cycles through five states, S0 to S4, in which four electrons are sequentially extracted from the OEC in four light-driven charge-separation events. Here we describe time resolved experiments on PSII nano/microcrystals from Thermosynechococcus elongatus performed with the recently developed technique of serial femtosecond crystallography. Structures have been determined from PSII in the dark S1 state and after double laser excitation (putative S3 state) at 5 and 5.5 A resolution, respectively. The results provide evidence that PSII undergoes significant conformational changes at the electron acceptor side and at the Mn4CaO5 core of the OEC. These include an elongation of the metal cluster, accompanied by changes in the protein environment, which could allow for binding of the second substrate water molecule between the more distant protruding Mn (referred to as the 'dangler' Mn) and the Mn3CaOx cubane in the S2 to S3 transition, as predicted by spectroscopic and computational studies. This work shows the great potential for time-resolved serial femtosecond crystallography for investigation of catalytic processes in biomolecules. Serial time-resolved crystallography of photosystem II using a femtosecond X-ray laser.,Kupitz C, Basu S, Grotjohann I, Fromme R, Zatsepin NA, Rendek KN, Hunter MS, Shoeman RL, White TA, Wang D, James D, Yang JH, Cobb DE, Reeder B, Sierra RG, Liu H, Barty A, Aquila AL, Deponte D, Kirian RA, Bari S, Bergkamp JJ, Beyerlein KR, Bogan MJ, Caleman C, Chao TC, Conrad CE, Davis KM, Fleckenstein H, Galli L, Hau-Riege SP, Kassemeyer S, Laksmono H, Liang M, Lomb L, Marchesini S, Martin AV, Messerschmidt M, Milathianaki D, Nass K, Ros A, Roy-Chowdhury S, Schmidt K, Seibert M, Steinbrener J, Stellato F, Yan L, Yoon C, Moore TA, Moore AL, Pushkar Y, Williams GJ, Boutet S, Doak RB, Weierstall U, Frank M, Chapman HN, Spence JC, Fromme P Nature. 2014 Jul 9. doi: 10.1038/nature13453. PMID:25043005 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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