2K7S

Human ARNT C-Terminal PAS Domain, 3 Residue IB slip


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 1000 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

ARNT PAS-B has a fragile native state structure with an alternative beta-sheet register nearby in sequence space

Evans, M.R.Card, P.B.Gardner, K.H.

(2009) Proc.Natl.Acad.Sci.USA 106: 2617-2622

  • DOI: 10.1073/pnas.0808270106

  • PubMed Abstract: 
  • The aryl hydrocarbon receptor nuclear translocator (ARNT) is a basic helix-loop-helix Period/ARNT/Single-minded (bHLH-PAS) protein that controls various biological pathways as part of dimeric transcriptional regulator complexes with other bHLH-PAS pr ...

    The aryl hydrocarbon receptor nuclear translocator (ARNT) is a basic helix-loop-helix Period/ARNT/Single-minded (bHLH-PAS) protein that controls various biological pathways as part of dimeric transcriptional regulator complexes with other bHLH-PAS proteins. The two PAS domains within ARNT, PAS-A and PAS-B, are essential for the formation of these complexes because they mediate protein-protein interactions via residues located on their beta-sheet surfaces. While investigating the importance of residues in ARNT PAS-B involved in these interactions, we uncovered a point mutation (Y456T) on the solvent-exposed beta-sheet surface that allowed this domain to interconvert with a second, stable conformation. Although both conformations are present in equivalent quantities in the Y456T mutant, this can be shifted almost completely to either end point by additional mutations. A high-resolution solution structure of a mutant ARNT PAS-B domain stabilized in the new conformation revealed a 3-residue slip in register and accompanying inversion of the central Ibeta-strand. We have demonstrated that the new conformation has >100-fold lower in vitro affinity for its heterodimerization partner, hypoxia-inducible factor 2alpha PAS-B. We speculate that the pliability in beta-strand register is related to the flexibility required of ARNT to bind to several partners and, more broadly, to the abilities of some PAS domains to regulate their activities in response to small-molecule cofactors.


    Related Citations: 
    • Structural Basis of ARNT PAS-B Dimerization: Use of a Common Beta-sheet Interface for Hetero- and Homodimerization
      Card, P.B.,Erbel, P.J.A.,Gardner, K.H.
      (2005) J.Mol.Biol. 353: 664


    Organizational Affiliation

    Departments of Biochemistry and Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390-8816, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Aryl hydrocarbon receptor nuclear translocator
A
119Homo sapiensGene Names: ARNT (BHLHE2)
Find proteins for P27540 (Homo sapiens)
Go to Gene View: ARNT
Go to UniProtKB:  P27540
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 1000 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 2K7S Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-01-20
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance