1TXX

ACTIVE-SITE VARIANT OF E.COLI THIOREDOXIN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Work: 0.171 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

The CXXC motif: crystal structure of an active-site variant of Escherichia coli thioredoxin.

Schultz, L.W.Chivers, P.T.Raines, R.T.

(1999) Acta Crystallogr.,Sect.D 55: 1533-1538


  • PubMed Abstract: 
  • The 2.2 A crystalline structure of an oxidized active-site variant of Escherichia coli thioredoxin (Trx) has been solved. Trx is a 12 kDa enzyme which catalyzes the oxidation of dithiols and the reduction and isomerization of disulfides in other prot ...

    The 2.2 A crystalline structure of an oxidized active-site variant of Escherichia coli thioredoxin (Trx) has been solved. Trx is a 12 kDa enzyme which catalyzes the oxidation of dithiols and the reduction and isomerization of disulfides in other proteins. Its active site contains the common structural motif CXXC. Protein-disulfide isomerase (PDI), a 57 kDa homolog of Trx, contains four Trx-like domains. The three-dimensional structure of PDI is unknown. PDI-deficient Saccharomyces cerevisiae are inviable. An active-site variant of Trx which complements PDI-deficient yeast has the active-site sequence Cys32-Val33-Trp34-Cys35 (CVWC). The reduction potential of oxidized CVWC Trx (E degrees ' = -0.230 V) is altered significantly from that of the wild-type enzyme (E degrees ' = -0.270 V). However, the structure of the oxidized CVWC enzyme is almost identical to that of wild-type Trx. The addition of valine and tryptophan in the active site is likely to increase the reduction potential, largely by decreasing the pK(a) of the Cys32 thiol in the reduced enzyme. Unlike in wild-type Trx, significant protein-protein contacts occur in the crystal. Protein molecules related by a crystallographic twofold axis form a dimer in the crystal. The dimer forms as an extension of the twisted mixed beta-sheet which composes the backbone of each Trx structure.


    Related Citations: 
    • The Cxxc Motif: Imperatives for the Formation of Native Disulfide Bonds
      Chivers, P.T.,Labiossiere, M.C.A.,Raines, R.T.
      (1996) Embo J. 15: 2659


    Organizational Affiliation

    Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (THIOREDOXIN)
A
108Escherichia coli (strain K12)Mutation(s): 2 
Gene Names: trxA (fipA, tsnC)
Find proteins for P0AA25 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AA25
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CU
Query on CU

Download SDF File 
Download CCD File 
A
COPPER (II) ION
Cu
JPVYNHNXODAKFH-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Work: 0.171 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 42.530α = 90.00
b = 42.530β = 90.00
c = 105.240γ = 90.00
Software Package:
Software NamePurpose
XSCALIBREdata reduction
XDSdata reduction
XSCALIBREdata scaling
XDSdata scaling
AMoREphasing
TNTrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-09-13
    Type: Initial release
  • Version 1.1: 2008-04-26
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-04
    Type: Advisory, Refinement description
  • Version 1.4: 2018-03-14
    Type: Database references