9HKR | pdb_00009hkr

NMR structure of the C-terminal domain of the human SPAG1 protein


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 120 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report

Validation slider image for 9HKR

This is version 1.1 of the entry. See complete history

Literature

An integrative structural biology approach reveals the dynamic organization of the R2SP quaternary chaperone complex.

Santo, P.E.Chagot, M.E.Gizardin-Fredon, H.Ley, M.Chenuel, T.Desligniere, E.Plassart, L.Paiva, A.C.F.Sousa, P.M.F.Bertrand, E.Charpentier, B.Verheggen, C.Quinternet, M.Meyer, P.Bandeiras, T.M.Cianferani, S.Plisson-Chastang, C.Manival, X.

(2026) Nat Commun 17

  • DOI: https://doi.org/10.1038/s41467-026-69157-x
  • Primary Citation Related Structures: 
    9HB4, 9HKR, 9HPO

  • PubMed Abstract: 

    R2SP belongs to the R2TP-like quaternary chaperone family and consists of RUVBL1/RUVBL2 AAA+ ATPases, which powers the machinery, and SPAG1 and PIH1D2 adapter proteins that engage specific clients to promote their quaternary assembly. However, little is known about the structure of R2SP and the precise mode of action of these R2TP-like complexes. Here, we combined biochemical (ATPase and fluorescence polarization assays) and structural approaches (NMR, structural mass spectrometry, cryo-EM) to investigate the 3D organization of the R2SP complex, its mode of assembly and ATPase activity. Together with our binding, mutational and kinetic studies, these results led us to propose a model in which SPAG1 and PIH1D2 bind and cooperatively engage RUVBL1/RUVBL2 to produce R2SP. This reveals a 3D structure close to the canonical R2TP complex but also highlights differences in RUVBL1/RUVBL2 ATPase activity, as well as the cooperative binding of SPAG1 and PIH1D2 to this catalytic core that may explain functional difference between the two systems.


  • Organizational Affiliation
    • Centre de Biologie Intégrative (CBI), University of Toulouse CNRS, Equipe labellisée Ligue Nationale Contre le Cancer, Toulouse, France.

Macromolecule Content 

  • Total Structure Weight: 15.52 kDa 
  • Atom Count: 1,090 
  • Modeled Residue Count: 135 
  • Deposited Residue Count: 135 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Sperm-associated antigen 1135Homo sapiensMutation(s): 0 
Gene Names: SPAG1
UniProt & NIH Common Fund Data Resources
Find proteins for Q07617 (Homo sapiens)
Explore Q07617 
Go to UniProtKB:  Q07617
PHAROS:  Q07617
GTEx:  ENSG00000104450 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ07617
Sequence Annotations
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Reference Sequence

Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 120 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

Structure Validation

View Full Validation Report



Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Centre National de la Recherche Scientifique (CNRS)France--

Revision History  (Full details and data files)

  • Version 1.0: 2025-12-17
    Type: Initial release
  • Version 1.1: 2026-07-01
    Changes: Database references