[English] 日本語
Yorodumi
- PDB-9qx5: Cryo-EM structure of the C. elegans UBR4/KCMF1 complex (side focu... -

+
Open data


ID or keywords:

Loading...

-
Basic information

Entry
Database: PDB / ID: 9qx5
TitleCryo-EM structure of the C. elegans UBR4/KCMF1 complex (side focused refinement)
ComponentsUBR-type domain-containing protein
KeywordsLIGASE / Ubiquitin ligase / protein quality control
Function / homology
Function and homology information


Antigen processing: Ubiquitination & Proteasome degradation / Neutrophil degranulation / DNA replication / zinc ion binding
Similarity search - Function
DNA polymerase processivity factor / DNA polymerase processivity factor / : / E3 ubiquitin-protein ligase UBR4-like domain / E3 ubiquitin ligase UBR4, C-terminal / E3 ubiquitin ligase UBR4-like / E3 ubiquitin-protein ligase UBR4 / UBR4 E3 catalytic module profile. / Putative zinc finger in N-recognin (UBR box) / Zinc finger, UBR-type ...DNA polymerase processivity factor / DNA polymerase processivity factor / : / E3 ubiquitin-protein ligase UBR4-like domain / E3 ubiquitin ligase UBR4, C-terminal / E3 ubiquitin ligase UBR4-like / E3 ubiquitin-protein ligase UBR4 / UBR4 E3 catalytic module profile. / Putative zinc finger in N-recognin (UBR box) / Zinc finger, UBR-type / Zinc finger UBR-type profile. / Putative zinc finger in N-recognin, a recognition component of the N-end rule pathway
Similarity search - Domain/homology
UBR-type domain-containing protein
Similarity search - Component
Biological speciesCaenorhabditis elegans (invertebrata)
MethodELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.5 Å
AuthorsGrabarczyk, D.B. / Clausen, T.
Funding support Austria, European Union, 2items
OrganizationGrant numberCountry
Austrian Research Promotion Agency852936 Austria
H2020 Marie Curie Actions of the European Commission847548European Union
CitationJournal: Science / Year: 2025
Title: Architecture of the UBR4 complex, a giant E4 ligase central to eukaryotic protein quality control.
Authors: Daniel B Grabarczyk / Julian F Ehrmann / Paul Murphy / Woo Seok Yang / Robert Kurzbauer / Lillie E Bell / Luiza Deszcz / Jana Neuhold / Alexander Schleiffer / Alexandra Shulkina / Juyeon Lee ...Authors: Daniel B Grabarczyk / Julian F Ehrmann / Paul Murphy / Woo Seok Yang / Robert Kurzbauer / Lillie E Bell / Luiza Deszcz / Jana Neuhold / Alexander Schleiffer / Alexandra Shulkina / Juyeon Lee / Jin Seok Shin / Anton Meinhart / Gijs A Versteeg / Eszter Zavodszky / Hyun Kyu Song / Ramanujan S Hegde / Tim Clausen /
Abstract: Eukaryotic cells have evolved sophisticated quality control mechanisms to eliminate aggregation-prone proteins that compromise cellular health. Central to this defense is the ubiquitin-proteasome ...Eukaryotic cells have evolved sophisticated quality control mechanisms to eliminate aggregation-prone proteins that compromise cellular health. Central to this defense is the ubiquitin-proteasome system, where UBR4 acts as an essential E4 ubiquitin ligase, amplifying degradation marks on defective proteins. Cryo-electron microscopy analysis of UBR4 in complex with its cofactors KCMF1 and CALM1 reveals a massive 1.3-megadalton ring structure, featuring a central substrate-binding arena and flexibly attached catalytic units. Our structure shows how UBR4 binds substrate and extends lysine-48-specific ubiquitin chains. Efficient substrate targeting depends on both preubiquitination and specific N-degrons, with KCMF1 acting as a key substrate filter. The architecture of the E4 megacomplex is conserved across eukaryotes, but species-specific adaptations allow UBR4 to perform its precisely tuned quality control function in diverse cellular environments.
History
DepositionApr 15, 2025Deposition site: PDBE / Processing site: PDBE
Revision 1.0Sep 3, 2025Provider: repository / Type: Initial release
Revision 1.1Sep 10, 2025Group: Data collection / Database references / Category: citation / citation_author / em_admin
Item: _citation.journal_volume / _citation.page_first ..._citation.journal_volume / _citation.page_first / _citation.page_last / _citation.pdbx_database_id_PubMed / _citation.title / _em_admin.last_update
Revision 1.2Sep 17, 2025Group: Data collection / Database references / Category: citation_author / em_admin
Item: _citation_author.identifier_ORCID / _em_admin.last_update
Revision 1.3Oct 22, 2025Group: Data collection / Category: em_admin / Item: _em_admin.last_update

-
Structure visualization

Structure viewerMolecule:
MolmilJmol/JSmol

Downloads & links

-
Assembly

Deposited unit
A: UBR-type domain-containing protein


Theoretical massNumber of molelcules
Total (without water)488,2451
Polymers488,2451
Non-polymers00
Water00
1


  • Idetical with deposited unit
  • defined by author&software
  • Evidence: electron microscopy, not applicable
TypeNameSymmetry operationNumber
identity operation1_555x,y,z1

-
Components

#1: Protein UBR-type domain-containing protein


Mass: 488244.844 Da / Num. of mol.: 1
Source method: isolated from a genetically manipulated source
Source: (gene. exp.) Caenorhabditis elegans (invertebrata) / Gene: ubr-4, C44E4.1, CELE_C44E4.1 / Production host: Trichoplusia ni (cabbage looper) / References: UniProt: A0A0S4XR36
Has protein modificationN

-
Experimental details

-
Experiment

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

-
Sample preparation

ComponentName: C. elegans UBR4/KCMF1 complex / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT
Molecular weightExperimental value: NO
Source (natural)Organism: Caenorhabditis elegans (invertebrata)
Source (recombinant)Organism: Trichoplusia ni (cabbage looper)
Buffer solutionpH: 7.5
SpecimenEmbedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES
VitrificationCryogen name: ETHANE

-
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: 2000 nm / Nominal defocus min: 800 nm
Image recordingElectron dose: 50 e/Å2 / Film or detector model: FEI FALCON IV (4k x 4k)

-
Processing

EM softwareName: PHENIX / Category: model refinement
CTF correctionType: PHASE FLIPPING AND AMPLITUDE CORRECTION
3D reconstructionResolution: 3.5 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 168687 / Details: Symmetry expanded / Symmetry type: POINT
RefinementHighest resolution: 3.5 Å
Stereochemistry target values: REAL-SPACE (WEIGHTED MAP SUM AT ATOM CENTERS)
Refine LS restraints
Refine-IDTypeDev idealNumber
ELECTRON MICROSCOPYf_bond_d0.00411794
ELECTRON MICROSCOPYf_angle_d0.63815957
ELECTRON MICROSCOPYf_dihedral_angle_d4.4411534
ELECTRON MICROSCOPYf_chiral_restr0.0441814
ELECTRON MICROSCOPYf_plane_restr0.0052014

+
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