Crystal structure of allosteric inhibitor, ARQ 092, in complex with autoinhibited form of AKT1

Experimental Data Snapshot

  • Resolution: 2.70 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.213 

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This is version 1.2 of the entry. See complete history


Discovery of 3-(3-(4-(1-Aminocyclobutyl)phenyl)-5-phenyl-3H-imidazo[4,5-b]pyridin-2-yl)pyridin-2-amine (ARQ 092): An Orally Bioavailable, Selective, and Potent Allosteric AKT Inhibitor.

Lapierre, J.M.Eathiraj, S.Vensel, D.Liu, Y.Bull, C.O.Cornell-Kennon, S.Iimura, S.Kelleher, E.W.Kizer, D.E.Koerner, S.Makhija, S.Matsuda, A.Moussa, M.Namdev, N.Savage, R.E.Szwaya, J.Volckova, E.Westlund, N.Wu, H.Schwartz, B.

(2016) J Med Chem 59: 6455-6469

  • DOI: https://doi.org/10.1021/acs.jmedchem.6b00619
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The work in this paper describes the optimization of the 3-(3-phenyl-3H-imidazo[4,5-b]pyridin-2-yl)pyridin-2-amine chemical series as potent, selective allosteric inhibitors of AKT kinases, leading to the discovery of ARQ 092 (21a). The cocrystal structure of compound 21a bound to full-length AKT1 confirmed the allosteric mode of inhibition of this chemical class and the role of the cyclobutylamine moiety. Compound 21a demonstrated high enzymatic potency against AKT1, AKT2, and AKT3, as well as potent cellular inhibition of AKT activation and the phosphorylation of the downstream target PRAS40. Compound 21a also served as a potent inhibitor of the AKT1-E17K mutant protein and inhibited tumor growth in a human xenograft mouse model of endometrial adenocarcinoma.

  • Organizational Affiliation

    ArQule Inc. , One Wall Street, Burlington, Massachusetts 01803, United States.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
RAC-alpha serine/threonine-protein kinase460Homo sapiensMutation(s): 3 
Gene Names: AKT1PKBRAC
UniProt & NIH Common Fund Data Resources
Find proteins for P31749 (Homo sapiens)
Explore P31749 
Go to UniProtKB:  P31749
PHAROS:  P31749
GTEx:  ENSG00000142208 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP31749
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on 6S1

Download Ideal Coordinates CCD File 
B [auth A]3-[3-[4-(1-azanylcyclobutyl)phenyl]-5-phenyl-imidazo[4,5-b]pyridin-2-yl]pyridin-2-amine
C27 H24 N6
Experimental Data & Validation

Experimental Data

  • Resolution: 2.70 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.213 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 44.72α = 90
b = 87.62β = 90
c = 128.79γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

  • Released Date: 2016-06-29 
  • Deposition Author(s): Eathiraj, S.

Revision History  (Full details and data files)

  • Version 1.0: 2016-06-29
    Type: Initial release
  • Version 1.1: 2016-07-27
    Changes: Database references
  • Version 1.2: 2023-09-27
    Changes: Data collection, Database references, Derived calculations, Refinement description