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Open data
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Basic information
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| Title | SSU processome maturation and disassembly, State N | |||||||||
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Keywords | SSU processome / ribosome assembly / RNA folding / RNA-protein interactions / RIBOSOME | |||||||||
| Function / homology | Function and homology information18S rRNA (adenine1779-N6/adenine1780-N6)-dimethyltransferase / 18S rRNA (adenine(1779)-N(6)/adenine(1780)-N(6))-dimethyltransferase activity / rRNA small subunit pseudouridine methyltransferase Nep1 / Noc4p-Nop14p complex / nuclear microtubule / Mpp10 complex / rRNA (pseudouridine) methyltransferase activity / rRNA modification / regulation of rRNA processing / rRNA (adenine-N6,N6-)-dimethyltransferase activity ...18S rRNA (adenine1779-N6/adenine1780-N6)-dimethyltransferase / 18S rRNA (adenine(1779)-N(6)/adenine(1780)-N(6))-dimethyltransferase activity / rRNA small subunit pseudouridine methyltransferase Nep1 / Noc4p-Nop14p complex / nuclear microtubule / Mpp10 complex / rRNA (pseudouridine) methyltransferase activity / rRNA modification / regulation of rRNA processing / rRNA (adenine-N6,N6-)-dimethyltransferase activity / RNA folding chaperone / endonucleolytic cleavage in 5'-ETS of tricistronic rRNA transcript (SSU-rRNA, 5.8S rRNA, LSU-rRNA) / endonucleolytic cleavage of tricistronic rRNA transcript (SSU-rRNA, 5.8S rRNA, LSU-rRNA) / endonucleolytic cleavage to generate mature 5'-end of SSU-rRNA from (SSU-rRNA, 5.8S rRNA, LSU-rRNA) / box C/D methylation guide snoRNP complex / single-stranded telomeric DNA binding / rRNA primary transcript binding / sno(s)RNA-containing ribonucleoprotein complex / rRNA base methylation / : / rRNA methylation / mTORC1-mediated signalling / Protein hydroxylation / U3 snoRNA binding / positive regulation of nuclear-transcribed mRNA catabolic process, deadenylation-dependent decay / Formation of the ternary complex, and subsequently, the 43S complex / Translation initiation complex formation / poly(A)+ mRNA export from nucleus / Ribosomal scanning and start codon recognition / preribosome, small subunit precursor / snoRNA binding / Major pathway of rRNA processing in the nucleolus and cytosol / SRP-dependent cotranslational protein targeting to membrane / GTP hydrolysis and joining of the 60S ribosomal subunit / Formation of a pool of free 40S subunits / Nonsense Mediated Decay (NMD) independent of the Exon Junction Complex (EJC) / Nonsense Mediated Decay (NMD) enhanced by the Exon Junction Complex (EJC) / L13a-mediated translational silencing of Ceruloplasmin expression / 90S preribosome / Ub-specific processing proteases / proteasome assembly / regulation of translational fidelity / ribosomal subunit export from nucleus / endonucleolytic cleavage in ITS1 to separate SSU-rRNA from 5.8S rRNA and LSU-rRNA from tricistronic rRNA transcript (SSU-rRNA, 5.8S rRNA, LSU-rRNA) / ribosomal small subunit export from nucleus / RNA endonuclease activity / nuclear periphery / ribosome assembly / maturation of SSU-rRNA from tricistronic rRNA transcript (SSU-rRNA, 5.8S rRNA, LSU-rRNA) / maturation of SSU-rRNA / translational initiation / small-subunit processome / enzyme activator activity / helicase activity / maintenance of translational fidelity / rRNA processing / unfolded protein binding / ribosome biogenesis / ribosomal small subunit biogenesis / ribosomal small subunit assembly / small ribosomal subunit / small ribosomal subunit rRNA binding / cytosolic small ribosomal subunit / Hydrolases; Acting on acid anhydrides; Acting on GTP to facilitate cellular and subcellular movement / cytoplasmic translation / RNA helicase activity / rRNA binding / structural constituent of ribosome / RNA helicase / ribosome / translation / GTPase activity / mRNA binding / GTP binding / nucleolus / ATP hydrolysis activity / mitochondrion / RNA binding / zinc ion binding / nucleoplasm / ATP binding / identical protein binding / nucleus / cytosol / cytoplasm Similarity search - Function | |||||||||
| Biological species | ![]() ![]() | |||||||||
| Method | single particle reconstruction / cryo EM / Resolution: 3.84 Å | |||||||||
Authors | Buzovetsky O / Klinge S | |||||||||
| Funding support | United States, 2 items
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Citation | Journal: Nature / Year: 2025Title: Helicase-mediated mechanism of SSU processome maturation and disassembly. Authors: Olga Buzovetsky / Sebastian Klinge / ![]() Abstract: Eukaryotic ribosomal small subunit (SSU) assembly requires the SSU processome, a nucleolar precursor containing the RNA chaperone U3 small nucleolar RNA (snoRNA). The underlying molecular mechanisms ...Eukaryotic ribosomal small subunit (SSU) assembly requires the SSU processome, a nucleolar precursor containing the RNA chaperone U3 small nucleolar RNA (snoRNA). The underlying molecular mechanisms of SSU processome maturation, remodelling, disassembly and RNA quality control, and the transitions between states remain unknown owing to a paucity of intermediates. Here we report 16 native SSU processome structures alongside genetic data, revealing how two helicases, the Mtr4-exosome and Dhr1, are controlled for accurate and unidirectional ribosome biogenesis. Our data show how irreversible pre-ribosomal RNA degradation by the redundantly tethered RNA exosome couples the transformation of the SSU processome into a pre-40S particle, during which Utp14 can probe evolving surfaces, ultimately positioning and activating Dhr1 to unwind the U3 snoRNA and initiate nucleolar pre-40S release. This study highlights a paradigm for large dynamic RNA-protein complexes in which irreversible RNA degradation drives compositional changes and communicates these changes to govern enzyme activity while maintaining overall quality control. | |||||||||
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Structure visualization
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Downloads & links
-EMDB archive
| Map data | emd_49090.map.gz | 238.5 MB | EMDB map data format | |
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| Header (meta data) | emd-49090-v30.xml emd-49090.xml | 64.4 KB 64.4 KB | Display Display | EMDB header |
| Images | emd_49090.png | 117.9 KB | ||
| Filedesc metadata | emd-49090.cif.gz | 17.9 KB | ||
| Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-49090 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-49090 | HTTPS FTP |
-Validation report
| Summary document | emd_49090_validation.pdf.gz | 623.2 KB | Display | EMDB validaton report |
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| Full document | emd_49090_full_validation.pdf.gz | 622.7 KB | Display | |
| Data in XML | emd_49090_validation.xml.gz | 7.9 KB | Display | |
| Data in CIF | emd_49090_validation.cif.gz | 9.2 KB | Display | |
| Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-49090 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-49090 | HTTPS FTP |
-Related structure data
| Related structure data | ![]() 9n7aMC ![]() 9n6vC ![]() 9n6wC ![]() 9n6xC ![]() 9n6yC ![]() 9n6zC ![]() 9n70C ![]() 9n73C ![]() 9n74C ![]() 9n75C ![]() 9n76C ![]() 9n77C ![]() 9n7bC M: atomic model generated by this map C: citing same article ( |
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| Similar structure data | Similarity search - Function & homology F&H Search |
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Links
| EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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| Related items in Molecule of the Month |
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Map
| File | Download / File: emd_49090.map.gz / Format: CCP4 / Size: 488.4 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
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| Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
| Voxel size | X=Y=Z: 1.063 Å | ||||||||||||||||||||||||||||||||||||
| Density |
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| Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
| Details | EMDB XML:
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-Supplemental data
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Sample components
+Entire : SSU processome maturation and disassembly, State N
+Supramolecule #1: SSU processome maturation and disassembly, State N
+Macromolecule #1: 18S rRNA
+Macromolecule #2: U3 snoRNA
+Macromolecule #15: U3snoRNA segment
+Macromolecule #3: 40S ribosomal protein S18-A
+Macromolecule #4: 40S ribosomal protein S4-A
+Macromolecule #5: 40S ribosomal protein S5
+Macromolecule #6: 40S ribosomal protein S6-A
+Macromolecule #7: 40S ribosomal protein S7-A
+Macromolecule #8: 40S ribosomal protein S8-A
+Macromolecule #9: 40S ribosomal protein S9-A
+Macromolecule #10: 40S ribosomal protein S16-A
+Macromolecule #11: 40S ribosomal protein S11-A
+Macromolecule #12: 40S ribosomal protein S22-A
+Macromolecule #13: 40S ribosomal protein S24-A
+Macromolecule #14: 40S ribosomal protein S28-A
+Macromolecule #16: U3 small nucleolar RNA-associated protein MPP10
+Macromolecule #17: Something about silencing protein 10
+Macromolecule #18: 40S ribosomal protein S13
+Macromolecule #19: 40S ribosomal protein S14-A
+Macromolecule #20: Dimethyladenosine transferase
+Macromolecule #21: Small ribosomal subunit protein eS1A
+Macromolecule #22: 40S ribosomal protein S19-A
+Macromolecule #23: 40S ribosomal protein S27-A
+Macromolecule #24: Probable ATP-dependent RNA helicase DHR1
+Macromolecule #25: 40S ribosomal protein S25-A
+Macromolecule #26: Ribosomal RNA-processing protein 9
+Macromolecule #27: RNA 3'-terminal phosphate cyclase-like protein
+Macromolecule #28: Ribosome biogenesis protein BMS1
+Macromolecule #29: Ribosomal RNA small subunit methyltransferase NEP1
+Macromolecule #30: rRNA-processing protein FCF1
+Macromolecule #31: U3 small nucleolar ribonucleoprotein protein IMP4
+Macromolecule #32: U3 small nucleolar RNA-associated protein 20
+Macromolecule #33: 40S ribosomal protein S23-A
+Macromolecule #34: U3 small nucleolar RNA-associated protein 14
+Macromolecule #35: Nucleolar complex protein 14
+Macromolecule #36: Nucleolar complex protein 4
+Macromolecule #37: Pre-rRNA-processing protein PNO1
+Macromolecule #38: Essential nuclear protein 1
+Macromolecule #39: MAGNESIUM ION
+Macromolecule #40: ZINC ION
+Macromolecule #41: GUANOSINE-5'-TRIPHOSPHATE
-Experimental details
-Structure determination
| Method | cryo EM |
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Processing | single particle reconstruction |
| Aggregation state | particle |
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Sample preparation
| Buffer | pH: 7.5 Component:
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| Vitrification | Cryogen name: ETHANE |
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Electron microscopy
| Microscope | TFS KRIOS |
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| Image recording | Film or detector model: GATAN K3 (6k x 4k) / Average electron dose: 61.6 e/Å2 |
| Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
| Electron optics | Illumination mode: OTHER / Imaging mode: BRIGHT FIELD / Nominal defocus max: 25.0 µm / Nominal defocus min: 1.0 µm |
| Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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About Yorodumi




Keywords
Authors
United States, 2 items
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Processing
FIELD EMISSION GUN
