The novel p300/CBP inhibitor A-485 uncovers a unique mechanism of action to target AR in castrate resistant prostate cancer

Experimental Data Snapshot

  • Resolution: 1.95 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.225 
  • R-Value Observed: 0.227 

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Ligand Structure Quality Assessment 

This is version 2.2 of the entry. See complete history


Discovery of a selective catalytic p300/CBP inhibitor that targets lineage-specific tumours.

Lasko, L.M.Jakob, C.G.Edalji, R.P.Qiu, W.Montgomery, D.Digiammarino, E.L.Hansen, T.M.Risi, R.M.Frey, R.Manaves, V.Shaw, B.Algire, M.Hessler, P.Lam, L.T.Uziel, T.Faivre, E.Ferguson, D.Buchanan, F.G.Martin, R.L.Torrent, M.Chiang, G.G.Karukurichi, K.Langston, J.W.Weinert, B.T.Choudhary, C.de Vries, P.Van Drie, J.H.McElligott, D.Kesicki, E.Marmorstein, R.Sun, C.Cole, P.A.Rosenberg, S.H.Michaelides, M.R.Lai, A.Bromberg, K.D.

(2017) Nature 550: 128-132

  • DOI: https://doi.org/10.1038/nature24028
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The dynamic and reversible acetylation of proteins, catalysed by histone acetyltransferases (HATs) and histone deacetylases (HDACs), is a major epigenetic regulatory mechanism of gene transcription and is associated with multiple diseases. Histone deacetylase inhibitors are currently approved to treat certain cancers, but progress on the development of drug-like histone actyltransferase inhibitors has lagged behind. The histone acetyltransferase paralogues p300 and CREB-binding protein (CBP) are key transcriptional co-activators that are essential for a multitude of cellular processes, and have also been implicated in human pathological conditions (including cancer). Current inhibitors of the p300 and CBP histone acetyltransferase domains, including natural products, bi-substrate analogues and the widely used small molecule C646, lack potency or selectivity. Here, we describe A-485, a potent, selective and drug-like catalytic inhibitor of p300 and CBP. We present a high resolution (1.95 Å) co-crystal structure of a small molecule bound to the catalytic active site of p300 and demonstrate that A-485 competes with acetyl coenzyme A (acetyl-CoA). A-485 selectively inhibited proliferation in lineage-specific tumour types, including several haematological malignancies and androgen receptor-positive prostate cancer. A-485 inhibited the androgen receptor transcriptional program in both androgen-sensitive and castration-resistant prostate cancer and inhibited tumour growth in a castration-resistant xenograft model. These results demonstrate the feasibility of using small molecule inhibitors to selectively target the catalytic activity of histone acetyltransferases, which may provide effective treatments for transcriptional activator-driven malignancies and diseases.

  • Organizational Affiliation

    Discovery, Global Pharmaceutical Research and Development, AbbVie, 1 North Waukegan Road, North Chicago, Illinois 60064, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Histone acetyltransferase p300348Homo sapiensMutation(s): 2 
Gene Names: EP300P300
UniProt & NIH Common Fund Data Resources
Find proteins for Q09472 (Homo sapiens)
Explore Q09472 
Go to UniProtKB:  Q09472
PHAROS:  Q09472
GTEx:  ENSG00000100393 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ09472
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on 6TF

Download Ideal Coordinates CCD File 
B [auth A]N-[(4-fluorophenyl)methyl]-2-{(1R)-5-[(methylcarbamoyl)amino]-2',4'-dioxo-2,3-dihydro-3'H-spiro[indene-1,5'-[1,3]oxazolidin]-3'-yl}-N-[(2S)-1,1,1-trifluoropropan-2-yl]acetamide
C25 H24 F4 N4 O5
Query on NA

Download Ideal Coordinates CCD File 
Binding Affinity Annotations 
IDSourceBinding Affinity
6TF BindingDB:  5KJ2 Kd: min: 1.28e-3, max: 1.4 (nM) from 2 assay(s)
IC50: min: 60, max: 67 (nM) from 2 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 1.95 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.225 
  • R-Value Observed: 0.227 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 45.192α = 90
b = 102.944β = 90
c = 168.438γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XDSdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2017-09-27
    Type: Initial release
  • Version 2.0: 2017-11-01
    Changes: Non-polymer description, Structure summary
  • Version 2.1: 2019-04-10
    Changes: Data collection, Database references
  • Version 2.2: 2023-09-27
    Changes: Data collection, Database references, Refinement description