4fby
fs X-ray diffraction of Photosystem IIfs X-ray diffraction of Photosystem II
Structural highlights
FunctionPSBA1_THEVB Photosystem II (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. The D1/D2 (PsbA/PsbD) reaction center heterodimer binds P680, the primary electron donor of PSII as well as several subsequent electron acceptors.[HAMAP-Rule:MF_01379][1] [2] [3] Publication Abstract from PubMedMost of the dioxygen on earth is generated by the oxidation of water by photosystem II (PS II) using light from the sun. This light-driven, four-photon reaction is catalyzed by the Mn(4)CaO(5) cluster located at the lumenal side of PS II. Various X-ray studies have been carried out at cryogenic temperatures to understand the intermediate steps involved in the water oxidation mechanism. However, the necessity for collecting data at room temperature, especially for studying the transient steps during the O-O bond formation, requires the development of new methodologies. In this paper we report room temperature X-ray diffraction data of PS II microcrystals obtained using ultrashort (< 50 fs) 9 keV X-ray pulses from a hard X-ray free electron laser, namely the Linac Coherent Light Source. The results presented here demonstrate that the "probe before destroy" approach using an X-ray free electron laser works even for the highly-sensitive Mn(4)CaO(5) cluster in PS II at room temperature. We show that these data are comparable to those obtained in synchrotron radiation studies as seen by the similarities in the overall structure of the helices, the protein subunits and the location of the various cofactors. This work is, therefore, an important step toward future studies for resolving the structure of the Mn(4)CaO(5) cluster without any damage at room temperature, and of the reaction intermediates of PS II during O-O bond formation. Room temperature femtosecond X-ray diffraction of photosystem II microcrystals.,Kern J, Alonso-Mori R, Hellmich J, Tran R, Hattne J, Laksmono H, Glockner C, Echols N, Sierra RG, Sellberg J, Lassalle-Kaiser B, Gildea RJ, Glatzel P, Grosse-Kunstleve RW, Latimer MJ, McQueen TA, Difiore D, Fry AR, Messerschmidt M, Miahnahri A, Schafer DW, Seibert MM, Sokaras D, Weng TC, Zwart PH, White WE, Adams PD, Bogan MJ, Boutet S, Williams GJ, Messinger J, Sauter NK, Zouni A, Bergmann U, Yano J, Yachandra VK Proc Natl Acad Sci U S A. 2012 Jun 4. PMID:22665786[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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OCA- Large Structures
- Thermosynechococcus vestitus BP-1
- Adams PD
- Alonso-Mori R
- Bergmann U
- Bogan MJ
- Boutet S
- Difiore D
- Echols N
- Fry AR
- Gildea RJ
- Glatzel P
- Gloeckner C
- Grosse-Kunstleve RW
- Hattne J
- Hellmich J
- Kern J
- Laksmono H
- Lassalle-Kaiser B
- Latimer MJ
- Mcqueen TA
- Messerschmidt MM
- Messinger J
- Miahnahri A
- Sauter NK
- Schafer DW
- Seibert MM
- Sellberg J
- Sierra RG
- Sokaras D
- Tran R
- Weng T-C
- White WE
- Williams GJ
- Yachandra VK
- Yano J
- Zouni A
- Zwart PH