| Structural highlights
5h2f is a 20 chain structure with sequence from Thermosynechococcus vestitus BP-1. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Method: | X-ray diffraction, Resolution 2.2Å |
| Ligands: | , , , , , , , , , , , , , , , , , , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
PSBA1_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/PsbA) 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 PubMed
Photosystem II (PSII) is a membrane protein complex that performs light-induced electron transfer and oxygen evolution from water. PSII consists of 19 or 20 subunits in its crystal form and binds various cofactors such as chlorophyll a, plastoquinone, carotenoid, and lipids. After initial light excitation, the charge separation produces an electron, which is transferred to a plastoquinone molecule (QA) and then to another plastoquinone (QB). PsbM is a low-molecular-weight subunit with one transmembrane helix, and is located in the monomer-monomer interface of the PSII dimer. The function of PsbM has been reported to be stabilization of the PSII dimer and maintenance of electron transfer efficiency of PSII based on previous X-ray crystal structure analysis at a resolution of 4.2 A. In order to elucidate the structure-function relationships of PsbM in detail, we improved the quality of PSII crystals from a PsbM-deleted mutant (DeltaPsbM-PSII) of Thermosynechococcus elongatus, and succeeded in improving the diffraction quality to a resolution of 2.2 A. X-ray crystal structure analysis of DeltaPsbM-PSII showed that electron densities for the PsbM subunit and neighboring carotenoid and detergent molecules were absent in the monomer-monomer interface. The overall structure of DeltaPsbM-PSII was similar to wild-type PSII, but the arrangement of the hydrophobic transmembrane subunits was significantly changed by the deletion of PsbM, resulting in a slight widening of the lipid hole involving QB. The lipid hole-widening further induced structural changes of the bicarbonate ion coordinated to the non-heme Fe(ii) atom and destabilized the polypeptide chains around the QB binding site located far from the position of PsbM. The fluorescence decay measurement indicated that the electron transfer rate from QA to QB was decreased in DeltaPsbM-PSII compared with wild-type PSII. The functional change in electron transfer efficiency was fully interpreted based on structural changes caused by the deletion of the PsbM subunit.
Mutual relationships between structural and functional changes in a PsbM-deletion mutant of photosystem II.,Uto S, Kawakami K, Umena Y, Iwai M, Ikeuchi M, Shen JR, Kamiya N Faraday Discuss. 2017 Mar 8. doi: 10.1039/c6fd00213g. PMID:28272640[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Broser M, Gabdulkhakov A, Kern J, Guskov A, Muh F, Saenger W, Zouni A. Crystal structure of monomeric photosystem II from Thermosynechococcus elongatus at 3.6-a resolution. J Biol Chem. 2010 Aug 20;285(34):26255-62. Epub 2010 Jun 17. PMID:20558739 doi:10.1074/jbc.M110.127589
- ↑ Broser M, Glockner C, Gabdulkhakov A, Guskov A, Buchta J, Kern J, Muh F, Dau H, Saenger W, Zouni A. Structural basis of cyanobacterial photosystem II Inhibition by the herbicide terbutryn. J Biol Chem. 2011 May 6;286(18):15964-72. Epub 2011 Mar 2. PMID:21367867 doi:http://dx.doi.org/10.1074/jbc.M110.215970
- ↑ Kern J, Tran R, Alonso-Mori R, Koroidov S, Echols N, Hattne J, Ibrahim M, Gul S, Laksmono H, Sierra RG, Gildea RJ, Han G, Hellmich J, Lassalle-Kaiser B, Chatterjee R, Brewster AS, Stan CA, Glockner C, Lampe A, DiFiore D, Milathianaki D, Fry AR, Seibert MM, Koglin JE, Gallo E, Uhlig J, Sokaras D, Weng TC, Zwart PH, Skinner DE, Bogan MJ, Messerschmidt M, Glatzel P, Williams GJ, Boutet S, Adams PD, Zouni A, Messinger J, Sauter NK, Bergmann U, Yano J, Yachandra VK. Taking snapshots of photosynthetic water oxidation using femtosecond X-ray diffraction and spectroscopy. Nat Commun. 2014 Jul 9;5:4371. doi: 10.1038/ncomms5371. PMID:25006873 doi:http://dx.doi.org/10.1038/ncomms5371
- ↑ Uto S, Kawakami K, Umena Y, Iwai M, Ikeuchi M, Shen JR, Kamiya N. Mutual relationships between structural and functional changes in a PsbM-deletion mutant of photosystem II. Faraday Discuss. 2017 Mar 8. doi: 10.1039/c6fd00213g. PMID:28272640 doi:http://dx.doi.org/10.1039/c6fd00213g
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