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- EMDB-25595: Consensus map of closed 40S ribosome from wt IRES eIF2-containing... -
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Open data
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Basic information
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Title | Consensus map of closed 40S ribosome from wt IRES eIF2-containing sample | |||||||||||||||
![]() | Post processed map | |||||||||||||||
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![]() | HCV / IRES / 40S / RIBOSOME | |||||||||||||||
Biological species | ![]() ![]() | |||||||||||||||
Method | single particle reconstruction / cryo EM / Resolution: 3.1 Å | |||||||||||||||
![]() | Brown ZP / Abaeva IS / De S / Hellen CUT / Pestova TV / Frank J | |||||||||||||||
Funding support | ![]()
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![]() | ![]() Title: Molecular architecture of 40S translation initiation complexes on the hepatitis C virus IRES. Authors: Zuben P Brown / Irina S Abaeva / Swastik De / Christopher U T Hellen / Tatyana V Pestova / Joachim Frank / ![]() Abstract: Hepatitis C virus mRNA contains an internal ribosome entry site (IRES) that mediates end-independent translation initiation, requiring a subset of eukaryotic initiation factors (eIFs). Biochemical ...Hepatitis C virus mRNA contains an internal ribosome entry site (IRES) that mediates end-independent translation initiation, requiring a subset of eukaryotic initiation factors (eIFs). Biochemical studies revealed that direct binding of the IRES to the 40S ribosomal subunit places the initiation codon into the P site, where it base pairs with eIF2-bound Met-tRNAiMet forming a 48S initiation complex. Subsequently, eIF5 and eIF5B mediate subunit joining, yielding an elongation-competent 80S ribosome. Initiation can also proceed without eIF2, in which case Met-tRNAiMet is recruited directly by eIF5B. However, the structures of initiation complexes assembled on the HCV IRES, the transitions between different states, and the accompanying conformational changes have remained unknown. To fill these gaps, we now obtained cryo-EM structures of IRES initiation complexes, at resolutions up to 3.5 Å, that cover all major stages from the initial ribosomal association, through eIF2-containing 48S initiation complexes, to eIF5B-containing complexes immediately prior to subunit joining. These structures provide insights into the dynamic network of 40S/IRES contacts, highlight the role of IRES domain II, and reveal conformational changes that occur during the transition from eIF2- to eIF5B-containing 48S complexes and prepare them for subunit joining. | |||||||||||||||
History |
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Structure visualization
Supplemental images |
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Downloads & links
-EMDB archive
Map data | ![]() | 228.3 MB | ![]() | |
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Header (meta data) | ![]() ![]() | 23.1 KB 23.1 KB | Display Display | ![]() |
FSC (resolution estimation) | ![]() | 14.2 KB | Display | ![]() |
Images | ![]() | 36.6 KB | ||
Masks | ![]() ![]() ![]() | 244.1 MB 244.1 MB 244.1 MB | ![]() | |
Filedesc metadata | ![]() | 4.7 KB | ||
Others | ![]() ![]() ![]() | 193.3 MB 194.4 MB 193.6 MB | ||
Archive directory | ![]() ![]() | HTTPS FTP |
-Validation report
Summary document | ![]() | 1 MB | Display | ![]() |
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Full document | ![]() | 1 MB | Display | |
Data in XML | ![]() | 21 KB | Display | |
Data in CIF | ![]() | 27.1 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 7syiC ![]() 7syjC ![]() 7sykC ![]() 7sylC ![]() 7syoC ![]() 7sypC ![]() 7syqC ![]() 7syrC ![]() 7sysC ![]() 7sytC ![]() 7syuC ![]() 7syvC ![]() 7sywC ![]() 7syxC C: citing same article ( |
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Links
EMDB pages | ![]() ![]() |
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Map
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Annotation | Post processed map | ||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 0.95 Å | ||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
-Mask #1
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-Mask #2
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-Mask #3
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-Additional map: Refine3D map
File | emd_25595_additional_1.map | ||||||||||||
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Annotation | Refine3D map | ||||||||||||
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-Half map: Half map
File | emd_25595_half_map_1.map | ||||||||||||
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Annotation | Half map | ||||||||||||
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-Half map: Half map
File | emd_25595_half_map_2.map | ||||||||||||
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Annotation | Half map | ||||||||||||
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Sample components
-Entire : 40S ribosomal small subunit with HCV IRES
Entire | Name: 40S ribosomal small subunit with HCV IRES |
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Components |
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-Supramolecule #1: 40S ribosomal small subunit with HCV IRES
Supramolecule | Name: 40S ribosomal small subunit with HCV IRES / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1-#39 |
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Source (natural) | Organism: ![]() ![]() |
Molecular weight | Theoretical: 2 MDa |
-Experimental details
-Structure determination
Method | cryo EM |
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![]() | single particle reconstruction |
Aggregation state | particle |
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Sample preparation
Concentration | 0.000075 mg/mL |
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Buffer | pH: 7.5 |
Grid | Model: Quantifoil R0.6/1 / Material: GOLD / Mesh: 300 / Support film - Material: GOLD / Support film - topology: HOLEY / Support film - Film thickness: 50 / Pretreatment - Type: PLASMA CLEANING / Pretreatment - Time: 25 sec. |
Vitrification | Cryogen name: ETHANE-PROPANE / Chamber humidity: 100 % / Chamber temperature: 277.15 K / Instrument: FEI VITROBOT MARK IV / Details: 4 second blot time, force 3. |
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Electron microscopy
Microscope | FEI TECNAI F30 |
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Image recording | Film or detector model: GATAN K3 (6k x 4k) / Average exposure time: 4.0 sec. / Average electron dose: 70.9 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: ![]() |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.26 mm / Nominal defocus max: 2.0 µm / Nominal defocus min: 1.0 µm / Nominal magnification: 52000 |
Sample stage | Cooling holder cryogen: NITROGEN |
Experimental equipment | ![]() Model: Tecnai F30 / Image courtesy: FEI Company |