5X54

Crystal structure of the Keap1 Kelch domain in complex with a tetrapeptide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.167 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Discovery of a Kelch-like ECH-associated protein 1-inhibitory tetrapeptide and its structural characterization

Sogabe, S.Sakamoto, K.Kamada, Y.Kadotani, A.Fukuda, Y.Sakamoto, J.

(2017) Biochem. Biophys. Res. Commun. 486: 620-625

  • DOI: 10.1016/j.bbrc.2017.03.038

  • PubMed Abstract: 
  • Keap1 constitutively binds to the transcription factor Nrf2 to promote its degradation, resulting in negative modulation of genes involved in cellular protection against oxidative stress. Keap1 is increasingly recognized as an attractive target for t ...

    Keap1 constitutively binds to the transcription factor Nrf2 to promote its degradation, resulting in negative modulation of genes involved in cellular protection against oxidative stress. Keap1 is increasingly recognized as an attractive target for treating diseases involving oxidative stress, including cancer, atherosclerosis, diabetes, arthritis, and neurodegeneration. We used phage-display peptide screening to identify a tetrapeptide showing moderate binding affinity, which inhibits the interaction between Nrf2 and Keap1. The tetrapeptide does not include an ETGE motif, which is a commonly found consensus sequence in known peptidic inhibitors. In addition to affinity parameters, IC50, KD, and thermodynamic parameters, the crystal structure of the complex was determined to elucidate the binding conformation. The binding interactions resemble those of known small-molecule inhibitors as opposed to those of substrates and peptidic inhibitors. Although the tetrapeptide's affinity is not very high, our results may help facilitate the designing of small-molecule inhibitors during lead generation in drug discovery.


    Organizational Affiliation

    Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555, Japan. Electronic address: satoshi.sogabe@takeda.com.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Kelch-like ECH-associated protein 1
A, B
291Homo sapiensMutation(s): 0 
Gene Names: KEAP1 (INRF2, KIAA0132, KLHL19)
Find proteins for Q14145 (Homo sapiens)
Go to Gene View: KEAP1
Go to UniProtKB:  Q14145
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
ACE-GLU-TRP-TRP-TRP
C, D
5N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ACT
Query on ACT

Download SDF File 
Download CCD File 
B
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
ACE
Query on ACE
C, D
NON-POLYMERC2 H4 O

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Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.167 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 68.566α = 90.00
b = 75.705β = 90.00
c = 168.132γ = 90.00
Software Package:
Software NamePurpose
MOLREPphasing
REFMACrefinement
SCALEPACKdata scaling
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2017-03-29
    Type: Initial release
  • Version 1.1: 2017-04-26
    Type: Database references