structure of HSP90 with an inhibitor bound

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.192 

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Ligand Structure Quality Assessment 

This is version 1.2 of the entry. See complete history


Discovery of Nms-E973 as Novel, Selective and Potent Inhibitor of Heat Shock Protein 90 (Hsp90).

Brasca, M.G.Mantegani, S.Amboldi, N.Bindi, S.Caronni, D.Casale, E.Ceccarelli, W.Colombo, N.De Ponti, A.Donati, D.Ermoli, A.Fachin, G.Felder, E.R.Ferguson, R.D.Fiorelli, C.Guanci, M.Isacchi, A.Pesenti, E.Polucci, P.Riceputi, L.Sola, F.Visco, C.Zuccotto, F.Fogliatto, G.

(2013) Bioorg Med Chem 21: 7047

  • DOI: https://doi.org/10.1016/j.bmc.2013.09.018
  • Primary Citation of Related Structures:  
    4BQG, 4BQJ

  • PubMed Abstract: 

    Novel small molecule inhibitors of heat shock protein 90 (Hsp90) were discovered with the help of a fragment based drug discovery approach (FBDD) and subsequent optimization with a combination of structure guided design, parallel synthesis and application of medicinal chemistry principles. These efforts led to the identification of compound 18 (NMS-E973), which displayed significant efficacy in a human ovarian A2780 xenograft tumor model, with a mechanism of action confirmed in vivo by typical modulation of known Hsp90 client proteins, and with a favorable pharmacokinetic and safety profile.

  • Organizational Affiliation

    Nerviano Medical Sciences S.r.l., Oncology, Viale Pasteur 10, 20014 Nerviano, MI, Italy. Electronic address: gabriella.brasca@nervianoms.com.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
HEAT SHOCK PROTEIN HSP 90-ALPHA230Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P07900 (Homo sapiens)
Explore P07900 
Go to UniProtKB:  P07900
PHAROS:  P07900
GTEx:  ENSG00000080824 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP07900
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on XKL

Download Ideal Coordinates CCD File 
B [auth A]5-[2,4-dihydroxy-6-(4-nitrophenoxy)phenyl]-N-ethyl-1,2-oxazole-3-carboxamide
C18 H15 N3 O7
Binding Affinity Annotations 
IDSourceBinding Affinity
XKL BindingDB:  4BQJ Kd: 0.8 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.192 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 53.699α = 90
b = 40.855β = 115.83
c = 54.221γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report

Ligand Structure Quality Assessment 

Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2013-10-23
    Type: Initial release
  • Version 1.1: 2013-10-30
    Changes: Database references
  • Version 1.2: 2017-06-28
    Changes: Data collection