Crystal structure of Bacillus subtilis cold shock protein CspB variant A46K S48R

Experimental Data Snapshot

  • Resolution: 2.30 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.205 

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Optimized variants of the cold shock protein from in vitro selection: structural basis of their high thermostability.

Max, K.E.Wunderlich, M.Roske, Y.Schmid, F.X.Heinemann, U.

(2007) J Mol Biol 369: 1087-1097

  • DOI: https://doi.org/10.1016/j.jmb.2007.04.016
  • Primary Citation of Related Structures:  
    2I5L, 2I5M

  • PubMed Abstract: 

    The bacterial cold shock proteins (Csp) are widely used as models for the experimental and computational analysis of protein stability. In a previous study, in vitro evolution was employed to identify strongly stabilizing mutations in Bs-CspB from Bacillus subtilis. The best variant found by this approach contained the mutations M1R, E3K and K65I, which raised the midpoint of thermal unfolding of Bs-CspB from 53.8 degrees C to 83.7 degrees C, and increased the Gibbs free energy of stabilization by 20.9 kJ mol(-1). Another selected variant with the two mutations A46K and S48R was stabilized by 11.1 kJ mol(-1). To elucidate the molecular basis of these stabilizations, we determined the crystal structures of these two Bs-CspB variants. The mutated residues are generally well ordered and provide additional stabilizing interactions, such as charge interactions, additional hydrogen bonds and improved side-chain packing. Several mutations improve the electrostatic interactions, either by the removal of unfavorable charges (E3K) or by compensating their destabilizing interactions (A46K, S48R). The stabilizing mutations are clustered at a contiguous surface area of Bs-CspB, which apparently is critically important for the stability of the beta-barrel structure but not well optimized in the wild-type protein.

  • Organizational Affiliation

    Makromolekulare Strukturen und Interaktionen, Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Cold shock protein cspBA [auth X]67Bacillus subtilisMutation(s): 2 
Gene Names: cspBcspA
Find proteins for P32081 (Bacillus subtilis (strain 168))
Explore P32081 
Go to UniProtKB:  P32081
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP32081
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on MG

Download Ideal Coordinates CCD File 
Experimental Data & Validation

Experimental Data

  • Resolution: 2.30 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.205 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 58.627α = 90
b = 58.627β = 90
c = 46.798γ = 120
Software Package:
Software NamePurpose
XSCALEdata scaling
PDB_EXTRACTdata extraction
MAR345data collection
XDSdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-05-22
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Derived calculations, Version format compliance
  • Version 1.3: 2017-10-18
    Changes: Refinement description
  • Version 1.4: 2021-10-20
    Changes: Database references, Derived calculations
  • Version 1.5: 2023-08-30
    Changes: Data collection, Refinement description