Biological Assembly 1  

 3D View: Structure | Electron Density

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Hetero 4-mer - A2B2 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 93.51 kDa 
• Atom Count: 6070 
• Residue Count: 768 
• Unique protein chains: 2

4LL4

The structure of the TRX and TXNIP complex

• DOI: 10.2210/pdb4LL4/pdb

• Classification: ANTITUMOR PROTEIN/PROTEIN BINDING
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2013-07-09 Released: 2014-02-05 
• Deposition Author(s): Hwang, J., Kim, M.H.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.70 Å
• R-Value Free: 0.264 
• R-Value Work: 0.196 
• R-Value Observed: 0.201 

Literature

The structural basis for the negative regulation of thioredoxin by thioredoxin-interacting protein

Hwang, J., Suh, H.W., Jeon, Y.H., Hwang, E., Nguyen, L.T., Yeom, J., Lee, S.G., Lee, C., Kim, K.J., Kang, B.S., Jeong, J.O., Oh, T.K., Choi, I., Lee, J.O., Kim, M.H.

(2014) Nat Commun 5: 2958-2958

• PubMed: 24389582 
• DOI: 10.1038/ncomms3958
• Primary Citation of Related Structures:  
  4GFX, 4LL1, 4LL4


• PubMed Abstract: 
  

The redox-dependent inhibition of thioredoxin (TRX) by thioredoxin-interacting protein (TXNIP) plays a pivotal role in various cancers and metabolic syndromes. However, the molecular mechanism of this regulation is largely unknown. Here, we present the crystal structure of the TRX-TXNIP complex and demonstrate that the inhibition of TRX by TXNIP is mediated by an intermolecular disulphide interaction resulting from a novel disulphide bond-switching mechanism. Upon binding to TRX, TXNIP undergoes a structural rearrangement that involves switching of a head-to-tail interprotomer Cys63-Cys247 disulphide between TXNIP molecules to an interdomain Cys63-Cys190 disulphide, and the formation of a de novo intermolecular TXNIP Cys247-TRX Cys32 disulphide. This disulphide-switching event unexpectedly results in a domain arrangement of TXNIP that is entirely different from those of other arrestin family proteins. We further show that the intermolecular disulphide bond between TRX and TXNIP dissociates in the presence of high concentrations of reactive oxygen species. This study provides insight into TRX and TXNIP-dependent cellular regulation.

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Organizational Affiliation: 

1] Infection and Immunity Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Korea [2] Biosystems and Bioengineering Program, University of Science and Technology, Daejeon 305-333, Korea.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Thioredoxin-interacting protein	A, C	315	Homo sapiens	Mutation(s): 3  Gene Names: TXNIP, VDUP1
Find proteins for Q9H3M7 (Homo sapiens) Explore Q9H3M7  Go to UniProtKB:  Q9H3M7
NIH Common Fund Data Resources
PHAROS  Q9H3M7 GTEx  ENSG00000265972

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Thioredoxin	B, D	105	Homo sapiens	Mutation(s): 1  Gene Names: TRX, TXN, TRDX, TRX1
Find proteins for P10599 (Homo sapiens) Explore P10599  Go to UniProtKB:  P10599
NIH Common Fund Data Resources
PHAROS  P10599 GTEx  ENSG00000136810

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.70 Å
• R-Value Free: 0.264 
• R-Value Work: 0.196 
• R-Value Observed: 0.201 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 79.826	α = 90
b = 64.99	β = 90.88
c = 88.416	γ = 90

Software Package:

Software Name	Purpose
HKL-2000	data collection
MOLREP	phasing
REFMAC	refinement
HKL-2000	data reduction
HKL-2000	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2013-07-09 
• Released Date: 2014-02-05 
Deposition Author(s): Hwang, J., Kim, M.H.

Revision History 

• Version 1.0: 2014-02-05
  Type: Initial release