Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.182 

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This is version 1.3 of the entry. See complete history


Structure of intact AhpF reveals a mirrored thioredoxin-like active site and implies large domain rotations during catalysis.

Wood, Z.A.Poole, L.B.Karplus, P.A.

(2001) Biochemistry 40: 3900-3911

  • DOI: https://doi.org/10.1021/bi002765p
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    AhpF, a homodimer of 57 kDa subunits, is a flavoenzyme which catalyzes the NADH-dependent reduction of redox-active disulfide bonds in the peroxidase AhpC, a member of the recently identified peroxiredoxin class of antioxidant enzymes. The structure of AhpF from Salmonella typhimurium at 2.0 A resolution, determined using multiwavelength anomalous dispersion, shows that the C-terminal portion of AhpF (residues 210-521) is structurally like Escherichia coli thioredoxin reductase. In addition, AhpF has an N-terminal domain (residues 1-196) formed from two contiguous thioredoxin folds, but containing just a single redox-active disulfide (Cys129-Cys132). A flexible linker (residues 197-209) connects the domains, consistent with experiments showing that the N-terminal domain acts as an appended substrate, first being reduced by the C-terminal portion of AhpF, and subsequently reducing AhpC. Modeling studies imply that an intrasubunit electron transfer accounts for the reduction of the N-terminal domain in dimeric AhpF. Furthermore, comparing the N-terminal domain with protein disulfide oxidoreductase from Pyrococcus furiosis, we describe a new class of protein disulfide oxidoreductases based on a novel mirror-image active site arrangement, with a distinct carboxylate (Glu86) being functionally equivalent to the key acid (Asp26) of E. coli thioredoxin. A final fortuitous result is that the N-terminal redox center is reduced and provides a high-resolution view of the thiol-thiolate hydrogen bond that has been predicted to stabilize the attacking thiolate in thioredoxin-like proteins.

  • Organizational Affiliation

    Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ALKYL HYDROPEROXIDE REDUCTASE SUBUNIT F521Salmonella enterica subsp. enterica serovar TyphimuriumMutation(s): 0 
EC: 1.8.1
Find proteins for P19480 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Explore P19480 
Go to UniProtKB:  P19480
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP19480
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.182 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 102.2α = 90
b = 139.16β = 90
c = 39.06γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
CCP4data scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-02-14
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2012-05-09
    Changes: Structure summary