+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-9995 | |||||||||
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Title | Structure of cyanobacterial photosystem I-IsiA supercomplex | |||||||||
Map data | The overall map | |||||||||
Sample |
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Function / homology | Function and homology information photosystem I reaction center / photosystem I / photosynthetic electron transport in photosystem I / photosystem I / photosynthetic electron transport chain / chlorophyll binding / plasma membrane-derived thylakoid membrane / photosynthesis / 4 iron, 4 sulfur cluster binding / electron transfer activity ...photosystem I reaction center / photosystem I / photosynthetic electron transport in photosystem I / photosystem I / photosynthetic electron transport chain / chlorophyll binding / plasma membrane-derived thylakoid membrane / photosynthesis / 4 iron, 4 sulfur cluster binding / electron transfer activity / oxidoreductase activity / magnesium ion binding / metal ion binding Similarity search - Function | |||||||||
Biological species | Synechococcus elongatus PCC 7942 (bacteria) / Synechococcus elongatus (strain PCC 7942) (bacteria) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 2.9 Å | |||||||||
Authors | Cao P / Cao DF / Si L / Su XD / Chang WR / Liu ZF / Zhang XZ / Li M | |||||||||
Citation | Journal: Nat Plants / Year: 2020 Title: Structural basis for energy and electron transfer of the photosystem I-IsiA-flavodoxin supercomplex. Authors: Peng Cao / Duanfang Cao / Long Si / Xiaodong Su / Lijin Tian / Wenrui Chang / Zhenfeng Liu / Xinzheng Zhang / Mei Li / Abstract: Under iron-deficiency stress, which occurs frequently in natural aquatic environments, cyanobacteria reduce the amount of iron-enriched proteins, including photosystem I (PSI) and ferredoxin (Fd), ...Under iron-deficiency stress, which occurs frequently in natural aquatic environments, cyanobacteria reduce the amount of iron-enriched proteins, including photosystem I (PSI) and ferredoxin (Fd), and upregulate the expression of iron-stress-induced proteins A and B (IsiA and flavodoxin (Fld)). Multiple IsiAs function as the peripheral antennae that encircle the PSI core, whereas Fld replaces Fd as the electron receptor of PSI. Here, we report the structures of the PSI-IsiA-Fld and PSI-IsiA supercomplexes from Synechococcus sp. PCC 7942, revealing features that are different from the previously reported PSI structures, and a sophisticated pigment network that involves previously unobserved pigment molecules. Spectroscopic results demonstrated that IsiAs are efficient light harvesters for PSI. Three Flds bind symmetrically to the trimeric PSI core-we reveal the detailed interaction and the electron transport path between PSI and Fld. Our results provide a structural basis for understanding the mechanisms of light harvesting, energy transfer and electron transport of cyanobacterial PSI under stressed conditions. | |||||||||
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_9995.map.gz | 393.8 MB | EMDB map data format | |
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Header (meta data) | emd-9995-v30.xml emd-9995.xml | 28.7 KB 28.7 KB | Display Display | EMDB header |
Images | emd_9995.png | 101.7 KB | ||
Others | emd_9995_additional_1.map.gz emd_9995_additional_2.map.gz | 103.6 MB 104.3 MB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-9995 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-9995 | HTTPS FTP |
-Validation report
Summary document | emd_9995_validation.pdf.gz | 541.9 KB | Display | EMDB validaton report |
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Full document | emd_9995_full_validation.pdf.gz | 541.5 KB | Display | |
Data in XML | emd_9995_validation.xml.gz | 7.6 KB | Display | |
Data in CIF | emd_9995_validation.cif.gz | 8.7 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-9995 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-9995 | HTTPS FTP |
-Related structure data
Related structure data | 6kigMC 9994C 6kifC 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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Related items in Molecule of the Month |
-Map
File | Download / File: emd_9995.map.gz / Format: CCP4 / Size: 421.9 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Annotation | The overall map | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 1.04 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
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-Supplemental data
-Additional map: The local density of six IsiAs
File | emd_9995_additional_1.map | ||||||||||||
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Annotation | The local density of six IsiAs | ||||||||||||
Projections & Slices |
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Density Histograms |
-Additional map: The local density of six IsiAs
File | emd_9995_additional_2.map | ||||||||||||
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Annotation | The local density of six IsiAs | ||||||||||||
Projections & Slices |
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Density Histograms |
-Sample components
+Entire : Photosystem I-IsiA supercomplex
+Supramolecule #1: Photosystem I-IsiA supercomplex
+Macromolecule #1: Photosystem I P700 chlorophyll a apoprotein A1
+Macromolecule #2: Photosystem I P700 chlorophyll a apoprotein A2
+Macromolecule #3: Photosystem I iron-sulfur center
+Macromolecule #4: Photosystem I reaction center subunit II
+Macromolecule #5: Photosystem I reaction center subunit IV
+Macromolecule #6: Photosystem I reaction center subunit III
+Macromolecule #7: Photosystem I PsaI protein
+Macromolecule #8: Photosystem I reaction center subunit IX
+Macromolecule #9: Photosystem I reaction center subunit PsaK
+Macromolecule #10: Photosystem I reaction center subunit XI
+Macromolecule #11: PsaM
+Macromolecule #12: Iron stress-induced chlorophyll-binding protein
+Macromolecule #13: CHLOROPHYLL A
+Macromolecule #14: PHYLLOQUINONE
+Macromolecule #15: IRON/SULFUR CLUSTER
+Macromolecule #16: BETA-CAROTENE
+Macromolecule #17: 1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE
+Macromolecule #18: DODECYL-ALPHA-D-MALTOSIDE
+Macromolecule #19: 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE
+Macromolecule #20: 1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL
+Macromolecule #21: water
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Concentration | 3 mg/mL |
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Buffer | pH: 7.5 |
Vitrification | Cryogen name: ETHANE |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Image recording | Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Detector mode: SUPER-RESOLUTION / Average electron dose: 60.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
-Image processing
Startup model | Type of model: PDB ENTRY PDB model - PDB ID: |
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Final reconstruction | Applied symmetry - Point group: C3 (3 fold cyclic) / Resolution.type: BY AUTHOR / Resolution: 2.9 Å / Resolution method: FSC 0.143 CUT-OFF / Number images used: 63332 |
Initial angle assignment | Type: PROJECTION MATCHING |
Final angle assignment | Type: PROJECTION MATCHING |
-Atomic model buiding 1
Refinement | Space: REAL |
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Output model | PDB-6kig: |