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Open data
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Basic information
Entry | Database: EMDB / ID: EMD-4242 | |||||||||
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Title | Human cap-dependent 48S pre-initiation complex | |||||||||
![]() | human 48S pre-initiation complex, reconstituted in the presence of capped mRNA, eIF4B and eIF4F, displaying eIF2 ternary complex, eIF3 and eIF4B | |||||||||
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Function / homology | ![]() positive regulation of mRNA binding / Cellular response to mitochondrial stress / viral translational termination-reinitiation / methionyl-initiator methionine tRNA binding / eukaryotic translation initiation factor 3 complex, eIF3e / Activation of the mRNA upon binding of the cap-binding complex and eIFs, and subsequent binding to 43S / Response of EIF2AK1 (HRI) to heme deficiency / eukaryotic translation initiation factor 3 complex, eIF3m / Recycling of eIF2:GDP / PERK regulates gene expression ...positive regulation of mRNA binding / Cellular response to mitochondrial stress / viral translational termination-reinitiation / methionyl-initiator methionine tRNA binding / eukaryotic translation initiation factor 3 complex, eIF3e / Activation of the mRNA upon binding of the cap-binding complex and eIFs, and subsequent binding to 43S / Response of EIF2AK1 (HRI) to heme deficiency / eukaryotic translation initiation factor 3 complex, eIF3m / Recycling of eIF2:GDP / PERK regulates gene expression / eukaryotic translation initiation factor 2 complex / formation of cytoplasmic translation initiation complex / eukaryotic translation initiation factor 3 complex / eukaryotic translation initiation factor 4F complex / Z-decay: degradation of maternal mRNAs by zygotically expressed factors / protein-synthesizing GTPase / eukaryotic 43S preinitiation complex / cytoplasmic translational initiation / translation factor activity, RNA binding / formation of translation preinitiation complex / Deadenylation of mRNA / positive regulation of cysteine-type endopeptidase activity involved in execution phase of apoptosis / negative regulation of endoplasmic reticulum unfolded protein response / oxidized pyrimidine DNA binding / response to TNF agonist / positive regulation of base-excision repair / eukaryotic 48S preinitiation complex / protein tyrosine kinase inhibitor activity / regulation of adenylate cyclase-activating G protein-coupled receptor signaling pathway / positive regulation of intrinsic apoptotic signaling pathway in response to DNA damage / positive regulation of gastrulation / IRE1-RACK1-PP2A complex / M-decay: degradation of maternal mRNAs by maternally stored factors / positive regulation of endodeoxyribonuclease activity / positive regulation of Golgi to plasma membrane protein transport / TNFR1-mediated ceramide production / negative regulation of DNA repair / negative regulation of RNA splicing / negative regulation of intrinsic apoptotic signaling pathway in response to hydrogen peroxide / oxidized purine DNA binding / supercoiled DNA binding / neural crest cell differentiation / NF-kappaB complex / ubiquitin-like protein conjugating enzyme binding / regulation of translational initiation / regulation of establishment of cell polarity / negative regulation of phagocytosis / rRNA modification in the nucleus and cytosol / Formation of the ternary complex, and subsequently, the 43S complex / erythrocyte homeostasis / cytoplasmic side of rough endoplasmic reticulum membrane / laminin receptor activity / nuclear-transcribed mRNA catabolic process, nonsense-mediated decay / protein kinase A binding / negative regulation of ubiquitin protein ligase activity / Ribosomal scanning and start codon recognition / ion channel inhibitor activity / Translation initiation complex formation / pigmentation / positive regulation of mitochondrial depolarization / mammalian oogenesis stage / activation-induced cell death of T cells / negative regulation of Wnt signaling pathway / positive regulation of T cell receptor signaling pathway / positive regulation of activated T cell proliferation / iron-sulfur cluster binding / regulation of cell division / Protein hydroxylation / negative regulation of peptidyl-serine phosphorylation / BH3 domain binding / mTORC1-mediated signalling / SARS-CoV-1 modulates host translation machinery / Peptide chain elongation / positive regulation of intrinsic apoptotic signaling pathway by p53 class mediator / cysteine-type endopeptidase activator activity involved in apoptotic process / Selenocysteine synthesis / positive regulation of signal transduction by p53 class mediator / Formation of a pool of free 40S subunits / Eukaryotic Translation Termination / phagocytic cup / ubiquitin ligase inhibitor activity / Response of EIF2AK4 (GCN2) to amino acid deficiency / SRP-dependent cotranslational protein targeting to membrane / negative regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction / Viral mRNA Translation / Nonsense Mediated Decay (NMD) independent of the Exon Junction Complex (EJC) / GTP hydrolysis and joining of the 60S ribosomal subunit / TOR signaling / L13a-mediated translational silencing of Ceruloplasmin expression / T cell proliferation involved in immune response / spindle assembly / Major pathway of rRNA processing in the nucleolus and cytosol / regulation of translational fidelity / erythrocyte development / Nonsense Mediated Decay (NMD) enhanced by the Exon Junction Complex (EJC) / negative regulation of ubiquitin-dependent protein catabolic process / Amplification of signal from unattached kinetochores via a MAD2 inhibitory signal / translation regulator activity / Nuclear events stimulated by ALK signaling in cancer / ribosomal small subunit export from nucleus Similarity search - Function | |||||||||
Biological species | ![]() ![]() | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 6.3 Å | |||||||||
![]() | Schaffitzel C | |||||||||
![]() | ![]() Title: Structure of a human cap-dependent 48S translation pre-initiation complex. Authors: Boris Eliseev / Lahari Yeramala / Alexander Leitner / Manikandan Karuppasamy / Etienne Raimondeau / Karine Huard / Elena Alkalaeva / Ruedi Aebersold / Christiane Schaffitzel / ![]() ![]() ![]() ![]() Abstract: Eukaryotic translation initiation is tightly regulated, requiring a set of conserved initiation factors (eIFs). Translation of a capped mRNA depends on the trimeric eIF4F complex and eIF4B to load ...Eukaryotic translation initiation is tightly regulated, requiring a set of conserved initiation factors (eIFs). Translation of a capped mRNA depends on the trimeric eIF4F complex and eIF4B to load the mRNA onto the 43S pre-initiation complex comprising 40S and initiation factors 1, 1A, 2, 3 and 5 as well as initiator-tRNA. Binding of the mRNA is followed by mRNA scanning in the 48S pre-initiation complex, until a start codon is recognised. Here, we use a reconstituted system to prepare human 48S complexes assembled on capped mRNA in the presence of eIF4B and eIF4F. The highly purified h-48S complexes are used for cross-linking/mass spectrometry, revealing the protein interaction network in this complex. We report the electron cryo-microscopy structure of the h-48S complex at 6.3 Å resolution. While the majority of eIF4B and eIF4F appear to be flexible with respect to the ribosome, additional density is detected at the entrance of the 40S mRNA channel which we attribute to the RNA-recognition motif of eIF4B. The eight core subunits of eIF3 are bound at the 40S solvent-exposed side, as well as the subunits eIF3d, eIF3b and eIF3i. elF2 and initiator-tRNA bound to the start codon are present at the 40S intersubunit side. This cryo-EM structure represents a molecular snap-shot revealing the h-48S complex following start codon recognition. | |||||||||
History |
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Structure visualization
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Structure viewer | EM map: ![]() ![]() ![]() |
Supplemental images |
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Downloads & links
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Map data | ![]() | 32.1 MB | ![]() | |
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Header (meta data) | ![]() ![]() | 71.1 KB 71.1 KB | Display Display | ![]() |
Images | ![]() | 56.4 KB | ||
Archive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 6fecMC ![]() 4265C M: atomic model generated by this map C: citing same article ( |
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Similar structure data |
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Links
EMDB pages | ![]() ![]() |
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Related items in Molecule of the Month |
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Map
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Annotation | human 48S pre-initiation complex, reconstituted in the presence of capped mRNA, eIF4B and eIF4F, displaying eIF2 ternary complex, eIF3 and eIF4B | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 2.5 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
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-Supplemental data
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Sample components
+Entire : human cap-dependent 48S translation pre-initiation complex
+Supramolecule #1: human cap-dependent 48S translation pre-initiation complex
+Supramolecule #2: human cap-dependent 48S translation pre-initiation complex
+Supramolecule #3: mRNA
+Supramolecule #4: Eukaryotic translation initiation factor 4B
+Macromolecule #1: Eukaryotic translation initiation factor 3 subunit A
+Macromolecule #2: Eukaryotic translation initiation factor 3 subunit C
+Macromolecule #3: Eukaryotic translation initiation factor 3 subunit E
+Macromolecule #4: Eukaryotic translation initiation factor 3 subunit F
+Macromolecule #5: Eukaryotic translation initiation factor 3 subunit H
+Macromolecule #6: Eukaryotic translation initiation factor 3 subunit K
+Macromolecule #7: Eukaryotic translation initiation factor 3 subunit L
+Macromolecule #8: Eukaryotic translation initiation factor 3 subunit M
+Macromolecule #9: EUKARYOTIC TRANSLATION INITIATION FACTOR 3 SUBUNIT D
+Macromolecule #12: 40S ribosomal protein S11
+Macromolecule #13: 40S ribosomal protein S16
+Macromolecule #14: 40S ribosomal protein S4, X isoform
+Macromolecule #15: 40S ribosomal protein S29
+Macromolecule #16: 40S ribosomal protein S9
+Macromolecule #17: 40S ribosomal protein S18
+Macromolecule #19: Eukaryotic translation initiation factor 2 subunit 1
+Macromolecule #20: 40S ribosomal protein S23
+Macromolecule #21: 40S ribosomal protein S19
+Macromolecule #22: Eukaryotic translation initiation factor 2 subunit 3
+Macromolecule #23: 40S ribosomal protein S5
+Macromolecule #24: 40S ribosomal protein S30
+Macromolecule #25: 40S ribosomal protein S25
+Macromolecule #26: 40S ribosomal protein S7
+Macromolecule #27: 40S ribosomal protein S27
+Macromolecule #28: 40S ribosomal protein S13
+Macromolecule #29: 40S ribosomal protein S15a
+Macromolecule #30: 40S ribosomal protein S21
+Macromolecule #31: 40S ribosomal protein S2
+Macromolecule #32: EUKARYOTIC TRANSLATION INITIATION FACTOR 2 BETA SUBUNIT (eIF2-Beta)
+Macromolecule #33: 40S ribosomal protein S17
+Macromolecule #34: 40S ribosomal protein SA
+Macromolecule #35: 40S ribosomal protein S3
+Macromolecule #36: 40S ribosomal protein S20
+Macromolecule #37: 40S ribosomal protein S3a
+Macromolecule #38: 40S ribosomal protein S14
+Macromolecule #39: 40S ribosomal protein S26
+Macromolecule #40: 40S ribosomal protein S28
+Macromolecule #41: Receptor of activated protein C kinase 1
+Macromolecule #42: 40S ribosomal protein S15
+Macromolecule #43: 40S ribosomal protein S8
+Macromolecule #44: Ubiquitin-40S ribosomal protein S27a
+Macromolecule #45: 40S ribosomal protein S6
+Macromolecule #46: 40S ribosomal protein S12
+Macromolecule #47: 40S ribosomal protein S24
+Macromolecule #48: 40S ribosomal protein S10
+Macromolecule #49: Eukaryotic translation initiation factor 4B
+Macromolecule #50: Eukaryotic translation initiation factor 3 subunit B
+Macromolecule #10: 18S ribosomal RNA
+Macromolecule #11: Messenger RNA (26-MER)
+Macromolecule #18: Transfer RNA (75-MER)
+Macromolecule #51: water
-Experimental details
-Structure determination
Method | cryo EM |
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![]() | single particle reconstruction |
Aggregation state | particle |
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Sample preparation
Buffer | pH: 7.5 Details: 20 mM Tris HCl, 50 mM KOAc, 2.5 mM MgCl2, 2 mM DTT, 0.25 mM spermidine 0.25 mM GMPPNP |
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Grid | Model: Quantifoil R2/2 |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 277 K / Instrument: FEI VITROBOT MARK IV |
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Electron microscopy
Microscope | FEI TITAN KRIOS |
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Image recording | Film or detector model: FEI FALCON II (4k x 4k) / Detector mode: INTEGRATING / Average electron dose: 30.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: ![]() |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Nominal defocus max: 4.0 µm / Nominal defocus min: 1.5 µm / Nominal magnification: 112000 |
Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN |
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Image processing
-Atomic model buiding 1
Refinement | Space: REAL / Protocol: RIGID BODY FIT / Target criteria: Cross-correlation coefficient |
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Output model | ![]() PDB-6fec: |