9XS6 | pdb_00009xs6

Factor inhibiting HIF-1 alpha in complex with Mn(II) and isofraxidin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.46 Å
  • R-Value Free: 
    0.256 (Depositor) 
  • R-Value Work: 
    0.215 (Depositor) 
  • R-Value Observed: 
    0.219 (Depositor) 

Starting Model: experimental
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wwPDB Validation

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This is version 1.0 of the entry. See complete history

Literature

Structural Insights into Metal-Chelating Natural Inhibitors of Factor Inhibiting HIF-1 alpha.

Akhsanitaqwim, Y.Nakashima, Y.Ikumi, N.Morita, H.

(2026) J Nat Prod 

  • DOI: https://doi.org/10.1021/acs.jnatprod.6c00734
  • Primary Citation Related Structures: 
    9XS3, 9XS4, 9XS5, 9XS6, 9XS7

  • PubMed Abstract: 

    Factor inhibiting HIF-1α (FIH) is a 2-oxoglutarate-dependent oxygenase that controls hypoxia signaling and metabolic homeostasis by hydroxylating HIF-1α. Although selective pharmacological inhibition of FIH represents an emerging therapeutic strategy for metabolic disorders, structurally diverse natural inhibitors remain largely unexplored. Here, we identified five natural FIH inhibitors spanning distinct phytochemical classes, including three flavonoids (wogonin, luteolin, morin), a coumarin (isofraxidin), and an anthraquinone (rhein). Co-crystal structures revealed that structurally diverse natural products converge on a common bidentate metal-chelation geometry within the FIH active site despite substantial differences in scaffold architecture. Among these inhibitors, wogonin most closely mimicked the orientation of the HIF-1α Asn803 side chain within the substrate-binding cleft, resulting in inhibitory potency comparable to that of the 2-oxoglutarate analog N -oxalylglycine. These findings establish the first structural framework for natural-product-based FIH inhibition and demonstrate that structurally distinct natural inhibitors adopt a conserved metal-chelation geometry within the FIH active site. This framework provides a basis for the future development of metabolically oriented FIH inhibitors.


  • Organizational Affiliation
    • Institute of Natural Medicine, University of Toyama, 2630-Sugitani, Toyama 930-0194, Japan.

Macromolecule Content 

  • Total Structure Weight: 41.09 kDa 
  • Atom Count: 2,888 
  • Modeled Residue Count: 343 
  • Deposited Residue Count: 349 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Hypoxia-inducible factor 1-alpha inhibitor349Homo sapiensMutation(s): 0 
Gene Names: HIF1ANFIH1
EC: 1.14.11.30 (PDB Primary Data), 1.14.11 (PDB Primary Data)
UniProt & NIH Common Fund Data Resources
Find proteins for Q9NWT6 (Homo sapiens)
Explore Q9NWT6 
Go to UniProtKB:  Q9NWT6
PHAROS:  Q9NWT6
GTEx:  ENSG00000166135 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9NWT6
Sequence Annotations
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Reference Sequence

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.46 Å
  • R-Value Free:  0.256 (Depositor) 
  • R-Value Work:  0.215 (Depositor) 
  • R-Value Observed: 0.219 (Depositor) 
Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 87.02α = 90
b = 87.02β = 90
c = 147.982γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

Currently 9XS6 does not have a validation slider image.



Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Japan Society for the Promotion of Science (JSPS)Japan24K18295
Japan Society for the Promotion of Science (JSPS)Japan25K02418

Revision History  (Full details and data files)

  • Version 1.0: 2026-08-12
    Type: Initial release