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Yorodumi- EMDB-13307: Cryo-EM structure of light harvesting complex 2 from Rba. sphaeroides. -
+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-13307 | |||||||||
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Title | Cryo-EM structure of light harvesting complex 2 from Rba. sphaeroides. | |||||||||
Map data | A light harvesting complex 2 (LH2) from photosynthetic bacterium of Rba. spheroids. | |||||||||
Sample |
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Function / homology | Function and homology information organelle inner membrane / plasma membrane light-harvesting complex / bacteriochlorophyll binding / photosynthesis, light reaction / electron transporter, transferring electrons within the cyclic electron transport pathway of photosynthesis activity / metal ion binding / plasma membrane Similarity search - Function | |||||||||
Biological species | Cereibacter sphaeroides 2.4.1 (bacteria) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 2.1 Å | |||||||||
Authors | Qian P / Swainsbury DJK / Croll TI / Castro-Hartmann P / Sader K / Divitini G / Hunter CN | |||||||||
Funding support | United Kingdom, 1 items
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Citation | Journal: Biochemistry / Year: 2021 Title: Cryo-EM Structure of the Light-Harvesting 2 Complex at 2.1 Å. Authors: Pu Qian / David J K Swainsbury / Tristan I Croll / Pablo Castro-Hartmann / Giorgio Divitini / Kasim Sader / C Neil Hunter / Abstract: Light-harvesting 2 (LH2) antenna complexes augment the collection of solar energy in many phototrophic bacteria. Despite its frequent role as a model for such complexes, there has been no three- ...Light-harvesting 2 (LH2) antenna complexes augment the collection of solar energy in many phototrophic bacteria. Despite its frequent role as a model for such complexes, there has been no three-dimensional (3D) structure available for the LH2 from the purple phototroph . We used cryo-electron microscopy (cryo-EM) to determine the 2.1 Å resolution structure of this LH2 antenna, which is a cylindrical assembly of nine αβ heterodimer subunits, each of which binds three bacteriochlorophyll (BChl) molecules and one carotenoid. The high resolution of this structure reveals all of the interpigment and pigment-protein interactions that promote the assembly and energy-transfer properties of this complex. Near the cytoplasmic face of the complex there is a ring of nine BChls, which absorb maximally at 800 nm and are designated as B800; each B800 is coordinated by the N-terminal carboxymethionine of LH2-α, part of a network of interactions with nearby residues on both LH2-α and LH2-β and with the carotenoid. Nine carotenoids, which are spheroidene in the strain we analyzed, snake through the complex, traversing the membrane and interacting with a ring of 18 BChls situated toward the periplasmic side of the complex. Hydrogen bonds with C-terminal aromatic residues modify the absorption of these pigments, which are red-shifted to 850 nm. Overlaps between the macrocycles of the B850 BChls ensure rapid transfer of excitation energy around this ring of pigments, which act as the donors of energy to neighboring LH2 and reaction center light-harvesting 1 (RC-LH1) complexes. | |||||||||
History |
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-Structure visualization
Movie |
Movie viewer |
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Structure viewer | EM map: SurfViewMolmilJmol/JSmol |
Supplemental images |
-Downloads & links
-EMDB archive
Map data | emd_13307.map.gz | 20.1 MB | EMDB map data format | |
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Header (meta data) | emd-13307-v30.xml emd-13307.xml | 16.5 KB 16.5 KB | Display Display | EMDB header |
FSC (resolution estimation) | emd_13307_fsc.xml | 13.5 KB | Display | FSC data file |
Images | emd_13307.png | 63.8 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-13307 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-13307 | HTTPS FTP |
-Validation report
Summary document | emd_13307_validation.pdf.gz | 386.3 KB | Display | EMDB validaton report |
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Full document | emd_13307_full_validation.pdf.gz | 385.8 KB | Display | |
Data in XML | emd_13307_validation.xml.gz | 13.2 KB | Display | |
Data in CIF | emd_13307_validation.cif.gz | 17.6 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-13307 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-13307 | HTTPS FTP |
-Related structure data
Related structure data | 7pbwMC M: atomic model generated by this map C: citing same article (ref.) |
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Similar structure data |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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-Map
File | Download / File: emd_13307.map.gz / Format: CCP4 / Size: 209.3 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Annotation | A light harvesting complex 2 (LH2) from photosynthetic bacterium of Rba. spheroids. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 0.66 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
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-Supplemental data
-Sample components
-Entire : Light harvesting complex 2
Entire | Name: Light harvesting complex 2 |
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Components |
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-Supramolecule #1: Light harvesting complex 2
Supramolecule | Name: Light harvesting complex 2 / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1-#2 |
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Source (natural) | Organism: Cereibacter sphaeroides 2.4.1 (bacteria) |
Molecular weight | Theoretical: 123.7 KDa |
-Macromolecule #1: Light-harvesting protein B-800/850 alpha chain
Macromolecule | Name: Light-harvesting protein B-800/850 alpha chain / type: protein_or_peptide / ID: 1 / Number of copies: 9 / Enantiomer: LEVO |
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Source (natural) | Organism: Cereibacter sphaeroides 2.4.1 (bacteria) |
Molecular weight | Theoretical: 5.275187 KDa |
Sequence | String: (CXM)TNGKIWLVV KPTVGVPLFL SAAVIASVVI HAAVLTTTTW LPAYYQGSAA |
-Macromolecule #2: Light-harvesting protein B-800/850 beta chain
Macromolecule | Name: Light-harvesting protein B-800/850 beta chain / type: protein_or_peptide / ID: 2 / Number of copies: 9 / Enantiomer: LEVO |
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Source (natural) | Organism: Cereibacter sphaeroides 2.4.1 (bacteria) |
Molecular weight | Theoretical: 4.99084 KDa |
Sequence | String: LNKVWPSGLT VAEAEEVHKQ LILGTRVFGG MALIAHFLAA AATPWLG |
-Macromolecule #3: BACTERIOCHLOROPHYLL A
Macromolecule | Name: BACTERIOCHLOROPHYLL A / type: ligand / ID: 3 / Number of copies: 27 / Formula: BCL |
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Molecular weight | Theoretical: 911.504 Da |
Chemical component information | ChemComp-BCL: |
-Macromolecule #4: SPHEROIDENE
Macromolecule | Name: SPHEROIDENE / type: ligand / ID: 4 / Number of copies: 9 / Formula: 7OT |
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Molecular weight | Theoretical: 568.914 Da |
Chemical component information | ChemComp-7OT: |
-Macromolecule #5: LAURYL DIMETHYLAMINE-N-OXIDE
Macromolecule | Name: LAURYL DIMETHYLAMINE-N-OXIDE / type: ligand / ID: 5 / Number of copies: 36 / Formula: LDA |
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Molecular weight | Theoretical: 229.402 Da |
Chemical component information | ChemComp-LDA: |
-Macromolecule #6: CALCIUM ION
Macromolecule | Name: CALCIUM ION / type: ligand / ID: 6 / Number of copies: 9 / Formula: CA |
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Molecular weight | Theoretical: 40.078 Da |
-Macromolecule #7: water
Macromolecule | Name: water / type: ligand / ID: 7 / Number of copies: 230 / Formula: HOH |
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Molecular weight | Theoretical: 18.015 Da |
Chemical component information | ChemComp-HOH: |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Concentration | 4.5 mg/mL |
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Buffer | pH: 7.8 / Component - Concentration: 20.0 mmol / Component - Formula: C8H18N2O4S / Component - Name: Hepes Details: The final sample buffer: 20 mM Hepes, pH 7.8, 0.1%LDAO |
Grid | Model: Quantifoil R1.2/1.3 / Material: COPPER / Mesh: 300 / Support film - Material: CARBON / Support film - topology: HOLEY ARRAY / Support film - Film thickness: 30.0 nm / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Time: 60 sec. / Pretreatment - Atmosphere: AIR / Details: easiGlow was used for glow discharge. |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 277 K / Instrument: FEI VITROBOT MARK IV |
Details | Sample was solubilised and purified with detergent of LDAO |
-Electron microscopy
Microscope | FEI TITAN |
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Specialist optics | Energy filter - Name: GIF Bioquantum / Energy filter - Slit width: 20 eV |
Image recording | Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) / Number grids imaged: 1 / Number real images: 3138 / Average exposure time: 1.37 sec. / Average electron dose: 41.6 e/Å2 Details: A total doe 41.6 was fractioned into 40 frames, resulting in an electron fluency of 1.04 e/A2/frame. |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.7 mm / Nominal defocus max: 2.2 µm / Nominal defocus min: 0.8 µm / Nominal magnification: 130000 |
Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN |