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- PDB-9es9: Cryo-EM structure of Spinacia oleracea cytochrome b6f complex wit... -
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Open data
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Basic information
Entry | Database: PDB / ID: 9es9 | ||||||||||||
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Title | Cryo-EM structure of Spinacia oleracea cytochrome b6f complex with inhibitor DBMIB bound at plastoquinol oxidation site | ||||||||||||
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![]() | OXIDOREDUCTASE / b6f complex / photosynthesis / membrane protein / electron transport / proton transport / inhibitor | ||||||||||||
Function / homology | ![]() PSII associated light-harvesting complex II binding / chloroplast photosystem I binding / chloroplast photosystem II binding / cytochrome b6f complex / plastoquinol-plastocyanin reductase / plastoquinol--plastocyanin reductase activity / : / thylakoid membrane / cytochrome complex assembly / photosynthetic electron transport chain ...PSII associated light-harvesting complex II binding / chloroplast photosystem I binding / chloroplast photosystem II binding / cytochrome b6f complex / plastoquinol-plastocyanin reductase / plastoquinol--plastocyanin reductase activity / : / thylakoid membrane / cytochrome complex assembly / photosynthetic electron transport chain / chloroplast thylakoid membrane / : / response to light stimulus / photosynthesis / chloroplast / respiratory electron transport chain / 2 iron, 2 sulfur cluster binding / electron transfer activity / oxidoreductase activity / iron ion binding / lipid binding / heme binding / metal ion binding / membrane / plasma membrane Similarity search - Function | ||||||||||||
Biological species | ![]() | ||||||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.33 Å | ||||||||||||
![]() | Pietras, R. / Pintscher, S. / Mielecki, B. / Szwalec, M. / Wojcik-Augustyn, A. / Indyka, P. / Rawski, M. / Koziej, L. / Jaciuk, M. / Wazny, G. ...Pietras, R. / Pintscher, S. / Mielecki, B. / Szwalec, M. / Wojcik-Augustyn, A. / Indyka, P. / Rawski, M. / Koziej, L. / Jaciuk, M. / Wazny, G. / Glatt, S. / Osyczka, A. | ||||||||||||
Funding support | ![]()
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![]() | ![]() Title: Molecular basis of plastoquinone reduction in plant cytochrome bf. Authors: Sebastian Pintscher / Rafał Pietras / Bohun Mielecki / Mateusz Szwalec / Anna Wójcik-Augustyn / Paulina Indyka / Michał Rawski / Łukasz Koziej / Marcin Jaciuk / Grzegorz Ważny / ...Authors: Sebastian Pintscher / Rafał Pietras / Bohun Mielecki / Mateusz Szwalec / Anna Wójcik-Augustyn / Paulina Indyka / Michał Rawski / Łukasz Koziej / Marcin Jaciuk / Grzegorz Ważny / Sebastian Glatt / Artur Osyczka / ![]() ![]() Abstract: A multi-subunit enzyme, cytochrome bf (cytbf), provides the crucial link between photosystems I and II in the photosynthetic membranes of higher plants, transferring electrons between plastoquinone ...A multi-subunit enzyme, cytochrome bf (cytbf), provides the crucial link between photosystems I and II in the photosynthetic membranes of higher plants, transferring electrons between plastoquinone (PQ) and plastocyanin. The atomic structure of cytbf is known, but its detailed catalytic mechanism remains elusive. Here we present cryogenic electron microscopy structures of spinach cytbf at 1.9 Å and 2.2 Å resolution, revealing an unexpected orientation of the substrate PQ in the haem ligand niche that forms the PQ reduction site (Q). PQ, unlike Q inhibitors, is not in direct contact with the haem. Instead, a water molecule is coordinated by one of the carbonyl groups of PQ and can act as the immediate proton donor for PQ. In addition, we identify water channels that connect Q with the aqueous exterior of the enzyme, suggesting that the binding of PQ in Q displaces water through these channels. The structures confirm large movements of the head domain of the iron-sulfur protein (ISP-HD) towards and away from the plastoquinol oxidation site (Q) and define the unique position of ISP-HD when a Q inhibitor (2,5-dibromo-3-methyl-6-isopropylbenzoquinone) is bound. This work identifies key conformational states of cytbf, highlights fundamental differences between substrates and inhibitors and proposes a quinone-water exchange mechanism. | ||||||||||||
History |
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 433.5 KB | Display | ![]() |
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PDB format | ![]() | 340.7 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
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-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 19940MC ![]() 9es7C ![]() 9es8C C: citing same article ( M: map data used to model this data |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
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Assembly
Deposited unit | ![]()
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Components
-Protein , 4 types, 8 molecules AICKDLQR
#1: Protein | Mass: 24186.504 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() #3: Protein | Mass: 35355.664 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() #4: Protein | Mass: 24347.898 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() References: UniProt: P08980, plastoquinol-plastocyanin reductase #9: Protein | Mass: 10608.004 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() |
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-Cytochrome b6-f complex subunit ... , 5 types, 10 molecules BJEMFNGOHP
#2: Protein | Mass: 17456.662 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() #5: Protein/peptide | Mass: 3452.200 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() #6: Protein | Mass: 12953.800 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() #7: Protein/peptide | Mass: 4171.985 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() #8: Protein/peptide | Mass: 3170.809 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) ![]() |
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-Non-polymers , 10 types, 230 molecules 


















#10: Chemical | ChemComp-HEM / #11: Chemical | ChemComp-HEC / #12: Chemical | ChemComp-UMQ / #13: Chemical | #14: Chemical | #15: Chemical | #16: Chemical | #17: Chemical | #18: Chemical | #19: Water | ChemComp-HOH / | |
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-Details
Has ligand of interest | Y |
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Has protein modification | Y |
-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
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Sample preparation
Component | Name: cytochrome b6f complex inhibited with DBMIB (2,5-DIBROMO-3-ISOPROPYL-6-METHYLBENZO-1,4-QUINONE) Type: COMPLEX / Entity ID: #1-#9 / Source: NATURAL | ||||||||||||||||||||||||||||||
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Molecular weight | Value: 0.22 MDa / Experimental value: NO | ||||||||||||||||||||||||||||||
Source (natural) | Organism: ![]() | ||||||||||||||||||||||||||||||
Buffer solution | pH: 7 | ||||||||||||||||||||||||||||||
Buffer component |
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Specimen | Conc.: 6.7 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES Details: final concentration of cytochrome b6f dimers 30.6 uM | ||||||||||||||||||||||||||||||
Specimen support | Grid material: COPPER / Grid mesh size: 200 divisions/in. / Grid type: Quantifoil R2/1 | ||||||||||||||||||||||||||||||
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277 K |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: TFS KRIOS |
Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 105000 X / Nominal defocus max: 2100 nm / Nominal defocus min: 900 nm / Cs: 2.7 mm / C2 aperture diameter: 50 µm |
Specimen holder | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Image recording | Electron dose: 41.34 e/Å2 / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) / Num. of grids imaged: 1 / Num. of real images: 3027 |
EM imaging optics | Energyfilter name: GIF Bioquantum / Energyfilter slit width: 20 eV |
Image scans | Width: 5760 / Height: 4092 |
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Processing
EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||||||||||||||
Particle selection | Num. of particles selected: 4120000 / Details: template picker, TOPAZ | ||||||||||||||||||||||||||||||||||||||||
Symmetry | Point symmetry: C2 (2 fold cyclic) | ||||||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 2.33 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 389849 / Algorithm: FOURIER SPACE / Num. of class averages: 1 / Symmetry type: POINT | ||||||||||||||||||||||||||||||||||||||||
Atomic model building | Protocol: RIGID BODY FIT / Space: REAL | ||||||||||||||||||||||||||||||||||||||||
Atomic model building | PDB-ID: 7ZYV Accession code: 7ZYV / Source name: PDB / Type: experimental model |