3ERW

Crystal Structure of StoA from Bacillus subtilis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.203 
  • R-Value Work: 0.183 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structure and Functional Properties of Bacillus subtilis Endospore Biogenesis Factor StoA

Crow, A.Liu, Y.Moller, M.C.Le Brun, N.E.Hederstedt, L.

(2009) J.Biol.Chem. 284: 10056-10066

  • DOI: 10.1074/jbc.M809566200

  • PubMed Abstract: 
  • Bacillus subtilis StoA is an extracytoplasmic thiol-disulfide oxidoreductase (TDOR) important for the synthesis of the endospore peptidoglycan cortex protective layer. Here we demonstrate that StoA is membrane-associated in B. subtilis and report the ...

    Bacillus subtilis StoA is an extracytoplasmic thiol-disulfide oxidoreductase (TDOR) important for the synthesis of the endospore peptidoglycan cortex protective layer. Here we demonstrate that StoA is membrane-associated in B. subtilis and report the crystal structure of the soluble protein lacking its membrane anchor. This showed that StoA adopts a thioredoxin-like fold with N-terminal and internal additions that are characteristic of extracytoplasmic TDORs. The CXXC active site of the crystallized protein was found to be in a mixture of oxidized and reduced states, illustrating that there is little conformational variation between redox states. The midpoint reduction potential was determined as -248 mV versus normal hydrogen electrode at pH 7 consistent with StoA fulfilling a reductive role in endospore biogenesis. pK(a) values of the active site cysteines, Cys-65 and Cys-68, were determined to be 5.5 and 7.8. Although Cys-68 is buried within the structure, both cysteines were found to be accessible to cysteine-specific alkylating reagents. In vivo studies of site-directed variants of StoA revealed that the active site cysteines are functionally important, as is Glu-71, which lies close to the active site and is conserved in many reducing extracytoplasmic TDORs. The structure and biophysical properties of StoA are very similar to those of ResA, a B. subtilis extracytoplasmic TDOR involved in cytochrome c maturation, raising important general questions about how these similar but non-redundant proteins achieve specificity. A detailed comparison of the two proteins demonstrates that relatively subtle differences, largely located around the active sites of the proteins, are sufficient to confer specificity.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Sporulation thiol-disulfide oxidoreductase A
A, B, C, D, E, F, G
145Bacillus subtilis (strain 168)Mutation(s): 0 
Gene Names: stoA (spoIVH)
Find proteins for O31687 (Bacillus subtilis (strain 168))
Go to UniProtKB:  O31687
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B, C, D, E, F, G
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.203 
  • R-Value Work: 0.183 
  • Space Group: P 31
Unit Cell:
Length (Å)Angle (°)
a = 133.717α = 90.00
b = 133.717β = 90.00
c = 64.820γ = 120.00
Software Package:
Software NamePurpose
ADSCdata collection
BP3model building
BP3phasing
SCALAdata scaling
PHENIXrefinement
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-01-20
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance