[English] 日本語
Yorodumi
- PDB-9z6i: Cryo-EM structure of the open state of cIL RNA at 4.3 A resolution -

+
Open data


ID or keywords:

Loading...

-
Basic information

Entry
Database: PDB / ID: 9z6i
TitleCryo-EM structure of the open state of cIL RNA at 4.3 A resolution
ComponentsRNA (155-MER)
KeywordsRNA / ribozyme / U1A / ribonucleoprotein (snRNP) complex
Function / homologyRNA / RNA (> 10) / RNA (> 100)
Function and homology information
Biological speciessynthetic construct (others)
MethodELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 4.32 Å
AuthorsFilippova, E.V. / Kossiakoff, A.A.
Funding support United States, 1items
OrganizationGrant numberCountry
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS) United States
CitationJournal: Nucleic Acids Res / Year: 2026
Title: A universal Fab targeting a conserved U1A-RNA epitope for RNA structure determination by cryo-EM.
Authors: Ekaterina V Filippova / Daniel Krochmal / Somnath Mukherjee / Joseph A Piccirilli / Anthony A Kossiakoff /
Abstract: Recent advances in cryo-electron microscopy (cryo-EM) have made antigen-binding fragments (Fabs) essential tools in the field of structural biology. Fabs facilitate image alignment, thereby enhancing ...Recent advances in cryo-electron microscopy (cryo-EM) have made antigen-binding fragments (Fabs) essential tools in the field of structural biology. Fabs facilitate image alignment, thereby enhancing three-dimensional (3D) reconstruction, and increase the effective size of proteins, aiding in their structural elucidation. In this study, we sought to broaden the use of Fabs as fiducial markers to elucidate the structures of RNA molecules. Identifying an appropriate Fab for a specific RNA target can be particularly challenging due to RNA's inherent flexibility and tendency to assume multiple conformations, which complicate the process and prolong the structure determination timeline. To address this challenge, we designed a universal Fab that specifically recognizes a U1A-RNA epitope, thereby reducing the need for Fab selection tailored to each individual RNA target. We determined the cryo-EM structure of the class I ligase ribozyme complexed with a portable U1hpII loop bound to the U1A protein and the Fab. The resulting structure revealed that the Fab interacts with a conserved U1A-RNA binding region, which can be engineered into other RNA molecules. This strategy presents significant potential for streamlining the structural determination of various RNAs, which are essential for biological and biomedical research.
History
DepositionNov 14, 2025Deposition site: RCSB / Processing site: RCSB
Revision 1.0May 27, 2026Provider: repository / Type: Initial release
Revision 1.0May 27, 2026Data content type: EM metadata / Data content type: EM metadata / Provider: repository / Type: Initial release
Revision 1.0May 27, 2026Data content type: FSC / Data content type: FSC / Provider: repository / Type: Initial release
Revision 1.0May 27, 2026Data content type: Half map / Part number: 1 / Data content type: Half map / Provider: repository / Type: Initial release
Revision 1.0May 27, 2026Data content type: Half map / Part number: 2 / Data content type: Half map / Provider: repository / Type: Initial release
Revision 1.0May 27, 2026Data content type: Image / Data content type: Image / Provider: repository / Type: Initial release
Revision 1.0May 27, 2026Data content type: Mask / Part number: 1 / Data content type: Mask / Provider: repository / Type: Initial release
Revision 1.0May 27, 2026Data content type: Primary map / Data content type: Primary map / Provider: repository / Type: Initial release
Revision 1.1Jun 3, 2026Group: Data collection / Database references / Category: citation / em_admin
Item: _citation.pdbx_database_id_PubMed / _citation.title / _em_admin.last_update
Revision 1.1Jun 3, 2026Data content type: EM metadata / Data content type: EM metadata / EM metadata / Group: Database references / Experimental summary / Data content type: EM metadata / EM metadata / Category: citation / em_admin / Data content type: EM metadata / EM metadata / EM metadata
Item: _citation.pdbx_database_id_PubMed / _citation.title / _em_admin.last_update

-
Structure visualization

Structure viewerMolecule:
MolmilJmol/JSmol

Downloads & links

-
Assembly

Deposited unit
A: RNA (155-MER)


Theoretical massNumber of molelcules
Total (without water)49,8361
Polymers49,8361
Non-polymers00
Water00
1


  • Idetical with deposited unit
  • defined by author
  • Evidence: electron microscopy, not applicable
TypeNameSymmetry operationNumber
identity operation1_5551

-
Components

#1: RNA chain RNA (155-MER)


Mass: 49835.676 Da / Num. of mol.: 1 / Source method: obtained synthetically
Details: RNA was produced in vitro by transcribing a synthetic DNA construct using T7 RNA polymerase from a linearized pUC307HP plasmid
Source: (synth.) synthetic construct (others)
Has ligand of interestY
Has protein modificationN

-
Experimental details

-
Experiment

ExperimentMethod: ELECTRON MICROSCOPY
EM experimentAggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction

-
Sample preparation

ComponentName: cIL-U1A-Fab1R-PGA1-sfFab18 quaternary complex / Type: COMPLEX / Entity ID: all / Source: MULTIPLE SOURCES
Molecular weightExperimental value: NO
Source (natural)Organism: synthetic construct (others)
Buffer solutionpH: 7.4 / Details: 10 mM HEPES, 75 mM NaCl, 5 mM MgCl2
SpecimenConc.: 3 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES
Specimen supportGrid material: GOLD / Grid mesh size: 300 divisions/in. / Grid type: Quantifoil R1.2/1.3
VitrificationInstrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 283 K

-
Electron microscopy imaging

Experimental equipment
Model: Titan Krios / Image courtesy: FEI Company
MicroscopyModel: TFS KRIOS
Electron gunElectron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM
Electron lensMode: BRIGHT FIELD / Nominal defocus max: 2500 nm / Nominal defocus min: 900 nm
Image recordingAverage exposure time: 7.1 sec. / Electron dose: 60 e/Å2 / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) / Num. of grids imaged: 2 / Num. of real images: 10696

-
Processing

EM software
IDNameVersionCategory
1cryoSPARC3.3.1particle selection
2PHENIX1.20.1_4487model refinement
13cryoSPARC3.3.13D reconstruction
CTF correctionType: PHASE FLIPPING AND AMPLITUDE CORRECTION
SymmetryPoint symmetry: C1 (asymmetric)
3D reconstructionResolution: 4.32 Å / Resolution method: OTHER / Num. of particles: 59244
Details: The final map resolution was estimated based on the gold-standard Fourier Shell Correlation (FSC) using the 0.143 cut-off criterion as implemented in cryoSPARC
Symmetry type: POINT
Atomic model buildingProtocol: AB INITIO MODEL / Space: REAL
Atomic model buildingPDB-ID: 3hhn

3hhn


Accession code: 3hhn / Source name: PDB / Type: experimental model
RefinementHighest resolution: 4.32 Å
Stereochemistry target values: REAL-SPACE (WEIGHTED MAP SUM AT ATOM CENTERS)

+
About Yorodumi

-
News

-
Feb 9, 2022. New format data for meta-information of EMDB entries

New format data for meta-information of EMDB entries

  • Version 3 of the EMDB header file is now the official format.
  • The previous official version 1.9 will be removed from the archive.

Related info.:EMDB header

External links:wwPDB to switch to version 3 of the EMDB data model

-
Aug 12, 2020. Covid-19 info

Covid-19 info

URL: https://pdbj.org/emnavi/covid19.php

New page: Covid-19 featured information page in EM Navigator.

Related info.:Covid-19 info / Mar 5, 2020. Novel coronavirus structure data

+
Mar 5, 2020. Novel coronavirus structure data

Novel coronavirus structure data

Related info.:Yorodumi Speices / Aug 12, 2020. Covid-19 info

External links:COVID-19 featured content - PDBj / Molecule of the Month (242)：Coronavirus Proteases

+
Jan 31, 2019. EMDB accession codes are about to change! (news from PDBe EMDB page)

EMDB accession codes are about to change! (news from PDBe EMDB page)

  • The allocation of 4 digits for EMDB accession codes will soon come to an end. Whilst these codes will remain in use, new EMDB accession codes will include an additional digit and will expand incrementally as the available range of codes is exhausted. The current 4-digit format prefixed with “EMD-” (i.e. EMD-XXXX) will advance to a 5-digit format (i.e. EMD-XXXXX), and so on. It is currently estimated that the 4-digit codes will be depleted around Spring 2019, at which point the 5-digit format will come into force.
  • The EM Navigator/Yorodumi systems omit the EMD- prefix.

Related info.:Q: What is EMD? / ID/Accession-code notation in Yorodumi/EM Navigator

External links:EMDB Accession Codes are Changing Soon! / Contact to PDBj

+
Jul 12, 2017. Major update of PDB

Major update of PDB

  • wwPDB released updated PDB data conforming to the new PDBx/mmCIF dictionary.
  • This is a major update changing the version number from 4 to 5, and with Remediation, in which all the entries are updated.
  • In this update, many items about electron microscopy experimental information are reorganized (e.g. em_software).
  • Now, EM Navigator and Yorodumi are based on the updated data.

External links:wwPDB Remediation / Enriched Model Files Conforming to OneDep Data Standards Now Available in the PDB FTP Archive

-
Yorodumi

Thousand views of thousand structures

  • Yorodumi is a browser for structure data from EMDB, PDB, SASBDB, etc.
  • This page is also the successor to EM Navigator detail page, and also detail information page/front-end page for Omokage search.
  • The word "yorodu" (or yorozu) is an old Japanese word meaning "ten thousand". "mi" (miru) is to see.

Related info.:EMDB / PDB / SASBDB / Comparison of 3 databanks / Yorodumi Search / Aug 31, 2016. New EM Navigator & Yorodumi / Yorodumi Papers / Jmol/JSmol / Function and homology information / Changes in new EM Navigator and Yorodumi

Read more