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PDBsum entry 4cxj

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Transcription PDB id
4cxj

 

 

 

 

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Contents
Protein chain
131 a.a.
Waters ×45
PDB id:
4cxj
Name: Transcription
Title: Btb domain of keap1 c151w mutant
Structure: Kelch-like ech-associated protein 1. Chain: a. Fragment: btb domain, residues 48-180. Synonym: cytosolic inhibitor of nrf2, inrf2, kelch-like protein 19, keap1. Engineered: yes. Mutation: yes
Source: Homo sapiens. Human. Organism_taxid: 9606. Expressed in: escherichia coli. Expression_system_taxid: 469008.
Resolution:
2.80Å     R-factor:   0.215     R-free:   0.271
Authors: A.Cleasby,J.Yon,P.J.Day,C.Richardson,I.J.Tickle,P.A.Williams, J.F.Callahan,R.Carr,N.Concha,J.K.Kerns,H.Qi,T.Sweitzer,P.Ward, T.G.Davies
Key ref: A.Cleasby et al. (2014). Structure of the BTB domain of Keap1 and its interaction with the triterpenoid antagonist CDDO. Plos One, 9, e98896. PubMed id: 24896564 DOI: 10.1371/journal.pone.0098896
Date:
07-Apr-14     Release date:   18-Jun-14    
PROCHECK
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 Headers
 References

Protein chain
Pfam   ArchSchema ?
Q14145  (KEAP1_HUMAN) -  Kelch-like ECH-associated protein 1 from Homo sapiens
Seq:
Struc:
 
Seq:
Struc:
624 a.a.
131 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 2 residue positions (black crosses)

 Enzyme reactions 
   Enzyme class: E.C.?
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]

 

 
DOI no: 10.1371/journal.pone.0098896 Plos One 9:e98896 (2014)
PubMed id: 24896564  
 
 
Structure of the BTB domain of Keap1 and its interaction with the triterpenoid antagonist CDDO.
A.Cleasby, J.Yon, P.J.Day, C.Richardson, I.J.Tickle, P.A.Williams, J.F.Callahan, R.Carr, N.Concha, J.K.Kerns, H.Qi, T.Sweitzer, P.Ward, T.G.Davies.
 
  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. 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.
 

 

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