9QF0

Cryo-EM structure of the mportin7:Histone H1.0 complex

This is a non-PDB format compatible entry.

Summary for 9QF0

• Entry DOI: 10.2210/pdb9qf0/pdb
• EMDB information: 0367
• Descriptor: Importin 7 L homeolog, Histone H1.0 (2 entities in total)
• Functional Keywords: transport, importin 7, histone 1.0, transport protein
• Biological source: Xenopus laevis (African clawed frog); More
• Total number of polymer chains: 2
• Total formula weight: 140480.34

Authors

Neumann, P.,Dickmanns, A. (deposition date: 2025-03-11, release date: 2026-01-14, Last modification date: 2026-01-28)

Primary citation

Neumann, P.,Dybkov, O.,Urlaub, H.,Ficner, R.,Dickmanns, A.
Alphafold 3-guided insights into the Importin beta : Importin7 heterodimer interaction and its binding to histone H1.
Structure, 2026

PubMed Abstract: The nuclear import of H1 linker histones is facilitated by a heterodimer of the transport receptors Importinβ (Impβ) and Importin7 (Imp7). The interaction between them is mediated by a stretch of C-terminal residues of Imp7 essential also for Imp7 activation by Impβ. An Impβ:Imp7:H1 complex model was predicted by Alphafold3 and validated using cross-linking data, isothermal titration calorimetry, and pull-down experiments, providing robust support for its accuracy. This model positions the H1 globular domain within the central cavity of Imp7. Refinement of this atomic model against a published cryo-electron microscopy (cryo-EM) map demonstrated significantly improved correspondence compared to the earlier interpretation, which placed the H1 globular domain within Impβ. This enhanced structural consistency further substantiates the accuracy of the AI-driven prediction. Moreover, a detailed analysis confirmed the extended C-terminal stretch of Imp7 harboring a nucleoporin-like binding (NlB) region with two FXFG-like nucleoporin motifs interacting with the outer surface of Impβ.

PubMed: 41529687
DOI: 10.1016/j.str.2025.12.011

Experimental method

ELECTRON MICROSCOPY (7.5 Å)