1CQH

HIGH RESOLUTION SOLUTION NMR STRUCTURE OF MIXED DISULFIDE INTERMEDIATE BETWEEN HUMAN THIOREDOXIN (C35A, C62A, C69A, C73A) MUTANT AND A 13 RESIDUE PEPTIDE COMPRISING ITS TARGET SITE IN HUMAN REF-1 (RESIDUES 59-71 OF THE P50 SUBUNIT OF NFKB), NMR, MINIMIZED AVERAGE STRUCTURE


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Submitted: 

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This is version 1.3 of the entry. See complete history


Literature

The solution structure of human thioredoxin complexed with its target from Ref-1 reveals peptide chain reversal.

Qin, J.Clore, G.M.Kennedy, W.P.Kuszewski, J.Gronenborn, A.M.

(1996) Structure 4: 613-620

  • DOI: https://doi.org/10.1016/s0969-2126(96)00065-2
  • Primary Citation of Related Structures:  
    1CQG, 1CQH

  • PubMed Abstract: 

    Human thioredoxin (hTRX) is a 12 kDa cellular redox protein that has been shown to play an important role in the activation of a number of transcriptional and translational regulators via a thiol-redox mechanism. This activity may be direct or indirect via another redox protein known as Ref-1. The structure of a complex of hTRX with a peptide comprising its target from the transcription factor NF kappa B has previously been solved. To further extend our knowledge of the recognition by and interaction of hTRX with its various targets, we have studied a complex between hTRX and a Ref-1 peptide. This complex represents a kinetically stable mixed disulfide intermediate along the reaction pathway. Using multidimensional heteronuclear edited and filtered NMR spectroscopy, we have solved the solution structure of a complex between hTRX and a 13-residue peptide comprising residues 59-71 of Ref-1. The Ref-1 peptide is located in a crescent-shaped groove on the surface of hTRX, the groove being formed by residues in the active-site loop (residues 32-36), helix 3, beta strands 3 and 5, and the loop between beta strands 3 and 4. The complex is stabilized by numerous hydrogen-bonding and hydrophobic interactions that involve residues 61-69 of the peptide and confer substrate specificity. The orientation of the Ref-1 peptide in the hTRX-Ref-1 complex is opposite to that found in the previously solved complex of hTRX with the target peptide from the transcription factor NF kappa B. Orientation is determined by three discriminating interactions involving the nature of the residues at the P-2' P-4 and P-5 binding positions. (P0 defines the active cysteine of the peptide, Cys65 for Ref-1 and Cys62 for NF kappa B. Positive and negative numbers indicate residues N-terminal and C-terminal to this residue, respectively, and vice versa for NF kappa B as it binds in the opposite orientation.) The environment surrounding the reactive Cys32 of hTRX, as well as the packing of the P+3 to P-4 residues are essentially the same in the two complexes, despite the opposing orientation of the peptide chains. This versatility in substrate recognition permits hTRX to act as a wide-ranging redox regulator for the cell.


  • Organizational Affiliation

    Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
THIOREDOXIN105Homo sapiensMutation(s): 4 
Gene Names: POTENTIAL
UniProt & NIH Common Fund Data Resources
Find proteins for P10599 (Homo sapiens)
Explore P10599 
Go to UniProtKB:  P10599
PHAROS:  P10599
GTEx:  ENSG00000136810 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP10599
Sequence Annotations
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  • Reference Sequence

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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
REF-1 PEPTIDE13Homo sapiensMutation(s): 0 
Gene Names: APEX1
EC: 4.2.99.18
UniProt & NIH Common Fund Data Resources
Find proteins for P27695 (Homo sapiens)
Explore P27695 
Go to UniProtKB:  P27695
PHAROS:  P27695
GTEx:  ENSG00000100823 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP27695
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Submitted: 

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1996-08-01
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2021-11-03
    Changes: Database references, Derived calculations, Other