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Yorodumi- EMDB-1250: Structure of the E. coli signal recognition particle bound to a t... -
+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-1250 | |||||||||
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Title | Structure of the E. coli signal recognition particle bound to a translating ribosome. | |||||||||
Map data | This is the map file of the E. coli signal recognition particle bound to a ribosome nascent chain complex. | |||||||||
Sample |
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Function / homology | Function and homology information signal recognition particle / signal-recognition-particle GTPase / 7S RNA binding / SRP-dependent cotranslational protein targeting to membrane / GTPase activity / GTP binding / ATP hydrolysis activity Similarity search - Function | |||||||||
Biological species | Escherichia coli (E. coli) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 15.5 Å | |||||||||
Authors | Schaffitzel C / Oswald M / Berger I / Ishikawa T / Abrahams JP / Koerten HK / Koning RI / Ban N | |||||||||
Citation | Journal: Nature / Year: 2006 Title: Structure of the E. coli signal recognition particle bound to a translating ribosome. Authors: Christiane Schaffitzel / Miro Oswald / Imre Berger / Takashi Ishikawa / Jan Pieter Abrahams / Henk K Koerten / Roman I Koning / Nenad Ban / Abstract: The prokaryotic signal recognition particle (SRP) targets membrane proteins into the inner membrane. It binds translating ribosomes and screens the emerging nascent chain for a hydrophobic signal ...The prokaryotic signal recognition particle (SRP) targets membrane proteins into the inner membrane. It binds translating ribosomes and screens the emerging nascent chain for a hydrophobic signal sequence, such as the transmembrane helix of inner membrane proteins. If such a sequence emerges, the SRP binds tightly, allowing the SRP receptor to lock on. This assembly delivers the ribosome-nascent chain complex to the protein translocation machinery in the membrane. Using cryo-electron microscopy and single-particle reconstruction, we obtained a 16 A structure of the Escherichia coli SRP in complex with a translating E. coli ribosome containing a nascent chain with a transmembrane helix anchor. We also obtained structural information on the SRP bound to an empty E. coli ribosome. The latter might share characteristics with a scanning SRP complex, whereas the former represents the next step: the targeting complex ready for receptor binding. High-resolution structures of the bacterial ribosome and of the bacterial SRP components are available, and their fitting explains our electron microscopic density. The structures reveal the regions that are involved in complex formation, provide insight into the conformation of the SRP on the ribosome and indicate the conformational changes that accompany high-affinity SRP binding to ribosome nascent chain complexes upon recognition of the signal sequence. | |||||||||
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_1250.map.gz | 4.6 MB | EMDB map data format | |
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Header (meta data) | emd-1250-v30.xml emd-1250.xml | 12.5 KB 12.5 KB | Display Display | EMDB header |
Images | 1250.gif | 39.4 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-1250 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-1250 | HTTPS FTP |
-Validation report
Summary document | emd_1250_validation.pdf.gz | 230 KB | Display | EMDB validaton report |
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Full document | emd_1250_full_validation.pdf.gz | 229.1 KB | Display | |
Data in XML | emd_1250_validation.xml.gz | 5.3 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-1250 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-1250 | HTTPS FTP |
-Related structure data
Related structure data | 2iy3MC 1251C 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_1250.map.gz / Format: CCP4 / Size: 5 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Annotation | This is the map file of the E. coli signal recognition particle bound to a ribosome nascent chain complex. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 3.81 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 : E. coli ribosome nascent chain complexes and signal recognition p...
Entire | Name: E. coli ribosome nascent chain complexes and signal recognition particle |
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Components |
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-Supramolecule #1000: E. coli ribosome nascent chain complexes and signal recognition p...
Supramolecule | Name: E. coli ribosome nascent chain complexes and signal recognition particle type: sample / ID: 1000 / Oligomeric state: One SRP binds to one ribosome. / Number unique components: 5 |
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-Supramolecule #1: E.coli 70S ribosome
Supramolecule | Name: E.coli 70S ribosome / type: complex / ID: 1 / Recombinant expression: No / Ribosome-details: ribosome-prokaryote: ALL |
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Source (natural) | Organism: Escherichia coli (E. coli) |
Molecular weight | Theoretical: 2.5 MDa |
-Macromolecule #1: A-site tRNA
Macromolecule | Name: A-site tRNA / type: rna / ID: 1 / Classification: TRANSFER / Structure: DOUBLE HELIX / Synthetic?: No |
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Source (natural) | Organism: Escherichia coli (E. coli) |
Molecular weight | Theoretical: 25 KDa |
-Macromolecule #2: P-site tRNA
Macromolecule | Name: P-site tRNA / type: rna / ID: 2 / Classification: TRANSFER / Structure: DOUBLE HELIX / Synthetic?: No |
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Source (natural) | Organism: Escherichia coli (E. coli) |
Molecular weight | Theoretical: 25 KDa |
-Macromolecule #3: E-site tRNA
Macromolecule | Name: E-site tRNA / type: rna / ID: 3 / Classification: TRANSFER / Structure: DOUBLE HELIX / Synthetic?: No |
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Source (natural) | Organism: Escherichia coli (E. coli) |
Molecular weight | Theoretical: 25 KDa |
-Macromolecule #4: E. coli SRP
Macromolecule | Name: E. coli SRP / type: ligand / ID: 4 / Name.synonym: Signal recognition particle / Number of copies: 1 / Oligomeric state: monomer / Recombinant expression: Yes |
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Source (natural) | Organism: Escherichia coli (E. coli) / Location in cell: cytosol |
Molecular weight | Theoretical: 90 KDa |
Recombinant expression | Organism: BL21StarDE3 / Recombinant plasmid: pET24a_Ffh and pUC19_Ffs |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Concentration | 0.25 mg/mL |
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Buffer | pH: 7.5 Details: 50 mM Hepes-KOH pH 7.5, 100 mM KCl, 25 mM MgCl2, 1 mM DTT, 1 mM GTP |
Grid | Details: carbon-coated lacey formvar grids |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 298 K / Instrument: HOMEMADE PLUNGER Details: Vitrification instrument: home-built environmental chamber and vitrification device Method: blot for 1.5 sec before plunging |
-Electron microscopy
Microscope | FEI TECNAI F20 |
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Image recording | Category: FILM / Film or detector model: KODAK SO-163 FILM / Digitization - Scanner: OTHER / Number real images: 251 / Average electron dose: 10 e/Å2 |
Electron beam | Acceleration voltage: 200 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Calibrated magnification: 51000 / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2 mm / Nominal defocus max: 4.5 µm / Nominal defocus min: 1.0 µm / Nominal magnification: 50000 |
Sample stage | Specimen holder: cryo stage / Specimen holder model: GATAN LIQUID NITROGEN |
Experimental equipment | Model: Tecnai F20 / Image courtesy: FEI Company |
-Image processing
Final reconstruction | Applied symmetry - Point group: C1 (asymmetric) / Resolution.type: BY AUTHOR / Resolution: 15.5 Å / Resolution method: FSC 0.5 CUT-OFF / Software - Name: Spider / Number images used: 24382 |
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-Atomic model buiding 1
Initial model | PDB ID: Chain - Chain ID: A |
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Software | Name: NOMAD |
Details | Protocol: normal mode based flexible fitting. Fitting of SRP atomic model into isolated EM density |
Refinement | Space: REAL / Protocol: FLEXIBLE FIT / Target criteria: correlation coefficient |
Output model | PDB-2iy3: |
-Atomic model buiding 2
Initial model | PDB ID: Chain - #0 - Chain ID: A / Chain - #1 - Chain ID: B |
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Software | Name: NOMAD |
Details | Protocol: normal mode based flexible fitting. Fitting of SRP atomic model into isolated EM density |
Refinement | Space: REAL / Protocol: FLEXIBLE FIT / Target criteria: correlation coefficient |
Output model | PDB-2iy3: |