Structure of CEHC variant ResA

Experimental Data Snapshot

  • Resolution: 2.50 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.178 
  • R-Value Observed: 0.182 

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Effects of substitutions in the CXXC active-site motif of the extracytoplasmic thioredoxin ResA.

Lewin, A.Crow, A.Hodson, C.T.Hederstedt, L.Le Brun, N.E.

(2008) Biochem J 414: 81-91

  • DOI: https://doi.org/10.1042/BJ20080356
  • Primary Citation of Related Structures:  
    3C71, 3C73

  • PubMed Abstract: 

    The thiol-disulfide oxidoreductase ResA from Bacillus subtilis fulfils a reductive role in cytochrome c maturation. The pK(a) values for the CEPC (one-letter code) active-site cysteine residues of ResA are unusual for thioredoxin-like proteins in that they are both high (>8) and within 0.5 unit of each other. To determine the contribution of the inter-cysteine dipeptide of ResA to its redox and acid-base properties, three variants (CPPC, CEHC and CPHC) were generated representing a stepwise conversion into the active-site sequence of the high-potential DsbA protein from Escherichia coli. The substitutions resulted in large decreases in the pK(a) values of both the active-site cysteine residues: in CPHC (DsbA-type) ResA, DeltapK(a) values of -2.5 were measured for both cysteine residues. Increases in midpoint reduction potentials were also observed, although these were comparatively small: CPHC (DsbA-type) ResA exhibited an increase of +40 mV compared with the wild-type protein. Unfolding studies revealed that, despite the observed differences in the properties of the reduced proteins, changes in stability were largely confined to the oxidized state. High-resolution structures of two of the variants (CEHC and CPHC ResA) in their reduced states were determined and are discussed in terms of the observed changes in properties. Finally, the in vivo functional properties of CEHC ResA are shown to be significantly affected compared with those of the wild-type protein.

  • Organizational Affiliation

    Centre for Molecular and Structural Biochemistry, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, UK.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Thiol-disulfide oxidoreductase resA
A, B
140Bacillus subtilisMutation(s): 1 
Gene Names: resAypxA
Find proteins for P35160 (Bacillus subtilis (strain 168))
Explore P35160 
Go to UniProtKB:  P35160
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP35160
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on SO4

Download Ideal Coordinates CCD File 
O4 S
Experimental Data & Validation

Experimental Data

  • Resolution: 2.50 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.178 
  • R-Value Observed: 0.182 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.219α = 90
b = 60.169β = 90
c = 110.393γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

  • Released Date: 2008-08-12 
  • Deposition Author(s): Crow, A.

Revision History  (Full details and data files)

  • Version 1.0: 2008-08-12
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2017-10-25
    Changes: Refinement description
  • Version 1.3: 2021-10-20
    Changes: Database references, Derived calculations