4CXT

BTB domain of KEAP1 in complex with CDDO


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.66 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.211 
  • R-Value Observed: 0.212 

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Ligand Structure Quality Assessment 


This is version 1.0 of the entry. See complete history


Literature

Structure of the Btb Domain of Keap1 and its Interaction with the Triterpenoid Antagonist Cddo.

Cleasby, A.Yon, J.Day, P.J.Richardson, C.Tickle, I.J.Williams, P.A.Callahan, J.F.Carr, R.Concha, N.Kerns, J.K.Qi, H.Sweitzer, T.Ward, P.Davies, T.G.

(2014) PLoS One 9: 98896

  • DOI: 10.1371/journal.pone.0098896
  • Primary Citation of Related Structures:  
    4CXI, 4CXJ, 4CXT

  • PubMed Abstract: 
  • The protein Keap1 is central to the regulation of the Nrf2-mediated cytoprotective response, and is increasingly recognized as an important target for therapeutic intervention in a range of diseases involving excessive oxidative stress and inflammation. The BTB domain of Keap1 plays key roles in sensing environmental electrophiles and in mediating interactions with the Cul3/Rbx1 E3 ubiquitin ligase system, and is believed to be the target for several small molecule covalent activators of the Nrf2 pathway ...

    The protein Keap1 is central to the regulation of the Nrf2-mediated cytoprotective response, and is increasingly recognized as an important target for therapeutic intervention in a range of diseases involving excessive oxidative stress and inflammation. The BTB domain of Keap1 plays key roles in sensing environmental electrophiles and in mediating interactions with the Cul3/Rbx1 E3 ubiquitin ligase system, and is believed to be the target for several small molecule covalent activators of the Nrf2 pathway. However, despite structural information being available for several BTB domains from related proteins, there have been no reported crystal structures of Keap1 BTB, and this has precluded a detailed understanding of its mechanism of action and interaction with antagonists. We report here the first structure of the BTB domain of Keap1, which is thought to contain the key cysteine residue responsible for interaction with electrophiles, as well as structures of the covalent complex with the antagonist CDDO/bardoxolone, and of the constitutively inactive C151W BTB mutant. In addition to providing the first structural confirmation of antagonist binding to Keap1 BTB, we also present biochemical evidence that adduction of Cys 151 by CDDO is capable of inhibiting the binding of Cul3 to Keap1, and discuss how this class of compound might exert Nrf2 activation through disruption of the BTB-Cul3 interface.


    Organizational Affiliation

    Astex Pharmaceuticals, Cambridge, United Kingdom.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
KELCH-LIKE ECH-ASSOCIATED PROTEIN 1A137Homo sapiensMutation(s): 1 
Gene Names: KEAP1INRF2KIAA0132KLHL19
UniProt & NIH Common Fund Data Resources
Find proteins for Q14145 (Homo sapiens)
Explore Q14145 
Go to UniProtKB:  Q14145
PHAROS:  Q14145
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ14145
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SXJ
Query on SXJ

Download Ideal Coordinates CCD File 
B [auth A](13alpha,18alpha)-2-cyano-3-hydroxy-12-oxooleana-2,9(11)-dien-28-oic acid
C31 H43 N O4
YTXFWWUYCLBPKV-UQMAOPSPSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.66 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.211 
  • R-Value Observed: 0.212 
  • Space Group: P 65 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.687α = 90
b = 42.687β = 90
c = 271.028γ = 120
Software Package:
Software NamePurpose
BUSTERrefinement
XDSdata reduction
SCALAdata scaling
CCP4phasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2014-06-18
    Type: Initial release