9BQ8 | pdb_00009bq8

Human Topoisomerase 2 Beta ATPase domain bound to non-hydrolyzable ATP analog AMPPNP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.25 Å
  • R-Value Free: 
    0.159 (Depositor), 0.159 (DCC) 
  • R-Value Work: 
    0.130 (Depositor), 0.130 (DCC) 
  • R-Value Observed: 
    0.130 (Depositor) 

Starting Model: experimental
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Literature

Topobexin targets the Topoisomerase II ATPase domain for beta isoform-selective inhibition and anthracycline cardioprotection.

Kubes, J.Karabanovich, G.Cong, A.T.Q.Melnikova, I.Lencova, O.Kollarova, P.Bavlovic Piskackova, H.Kerestes, V.Applova, L.Arrouye, L.C.M.Alvey, J.R.Paluncic, J.Witter, T.L.Jirkovska, A.Kunes, J.Sterbova-Kovarikova, P.Austin, C.A.Sterba, M.Simunek, T.Roh, J.Schellenberg, M.J.

(2025) Nat Commun 16: 4928-4928

  • DOI: https://doi.org/10.1038/s41467-025-60167-9
  • Primary Citation of Related Structures:  
    9BQ6, 9BQ7, 9BQ8, 9BQ9, 9BQA, 9BQB, 9BQC, 9BQD

  • PubMed Abstract: 

    Topoisomerase II alpha and beta (TOP2A and TOP2B) isoenzymes perform essential and non-redundant cellular functions. Anthracyclines induce their potent anti-cancer effects primarily via TOP2A, but at the same time they induce a dose limiting cardiotoxicity through TOP2B. Here we describe the development of the obex class of TOP2 inhibitors that bind to a previously unidentified druggable pocket in the TOP2 ATPase domain to act as allosteric catalytic inhibitors by locking the ATPase domain conformation with the capability of isoform-selective inhibition. Through rational drug design we have developed topobexin, which interacts with residues that differ between TOP2A and TOP2B to provide inhibition that is both selective for TOP2B and superior to dexrazoxane. Topobexin is a potent protectant against chronic anthracycline cardiotoxicity in an animal model. This demonstration of TOP2 isoform-specific inhibition underscores the broader potential to improve drug specificity and minimize adverse effects in various medical treatments.


  • Organizational Affiliation

    Department of Biochemical Sciences, Faculty of Pharmacy in Hradec Králové, Charles University; Hradec, Králové, 500 03, Czech Republic.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
DNA topoisomerase 2-beta397Homo sapiensMutation(s): 0 
Gene Names: TOP2B
EC: 5.6.2.2
UniProt & NIH Common Fund Data Resources
Find proteins for Q02880 (Homo sapiens)
Explore Q02880 
Go to UniProtKB:  Q02880
PHAROS:  Q02880
GTEx:  ENSG00000077097 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ02880
Sequence Annotations
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.25 Å
  • R-Value Free:  0.159 (Depositor), 0.159 (DCC) 
  • R-Value Work:  0.130 (Depositor), 0.130 (DCC) 
  • R-Value Observed: 0.130 (Depositor) 
Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 83.766α = 90
b = 83.766β = 90
c = 127.108γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
SCALEPACKdata scaling
DENZOdata reduction
PHENIXphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Revision History  (Full details and data files)

  • Version 1.0: 2025-06-25
    Type: Initial release