Human HSP90 alpha N-terminal domain in complex with an Aminotriazoloquinazoline inhibitor

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.199 

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Ligand Structure Quality Assessment 

This is version 1.3 of the entry. See complete history


Fragment-Based Hit Discovery and Structure-Based Optimization of Aminotriazoloquinazolines as Novel Hsp90 Inhibitors.

Casale, E.Amboldi, N.Brasca, M.G.Caronni, D.Colombo, N.Dalvit, C.Felder, E.R.Fogliatto, G.Galvani, A.Isacchi, A.Polucci, P.Riceputi, L.Sola, F.Visco, C.Zuccotto, F.Casuscelli, F.

(2014) Bioorg Med Chem 22: 4135

  • DOI: https://doi.org/10.1016/j.bmc.2014.05.056
  • Primary Citation of Related Structures:  
    4CWF, 4CWN, 4CWO, 4CWP, 4CWQ, 4CWR, 4CWS, 4CWT

  • PubMed Abstract: 

    In the last decade the heat shock protein 90 (Hsp90) has emerged as a major therapeutic target and many efforts have been dedicated to the discovery of Hsp90 inhibitors as new potent anticancer agents. Here we report the identification of a novel class of Hsp90 inhibitors by means of a biophysical FAXS-NMR based screening of a library of fragments. The use of X-ray structure information combined with modeling studies enabled the fragment evolution of the initial triazoloquinazoline hit to a class of compounds with nanomolar potency and drug-like properties suited for further lead optimization.

  • Organizational Affiliation

    Oncology, Nerviano Medical Sciences, Viale Pasteur 10, 20014 Nerviano (MI), Italy. Electronic address: elena.casale@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 W2D

Download Ideal Coordinates CCD File 
B [auth A]2-amino-5-(1,3-benzodioxol-5-ylmethyl)[1,2,4]triazolo[1,5-c]quinazoline-8-sulfonamide
C17 H14 N6 O4 S
Binding Affinity Annotations 
IDSourceBinding Affinity
W2D BindingDB:  4CWQ Ki: 88 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.199 
  • Space Group: I 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 67.06α = 90
b = 91.007β = 90
c = 98.607γ = 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: 2014-07-09
    Type: Initial release
  • Version 1.1: 2014-08-06
    Changes: Database references
  • Version 1.2: 2017-06-28
    Changes: Data collection
  • Version 1.3: 2024-05-08
    Changes: Data collection, Database references, Derived calculations, Other