4L2A

X-ray structure of the C57R mutant of the iron superoxide dismutase from Pseudoalteromonas haloplanktis (crystal form II)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.06 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Structural and denaturation studies of two mutants of a cold adapted superoxide dismutase point to the importance of electrostatic interactions in protein stability.

Merlino, A.Russo Krauss, I.Castellano, I.Ruocco, M.R.Capasso, A.De Vendittis, E.Rossi, B.Sica, F.

(2014) Biochim.Biophys.Acta 1844: 632-640

  • DOI: 10.1016/j.bbapap.2014.01.007
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • A peculiar feature of the psychrophilic iron superoxide dismutase from Pseudoalteromonas haloplanktis (PhSOD) is the presence in its amino acid sequence of a reactive cysteine (Cys57). To define the role of this residue, a structural characterization ...

    A peculiar feature of the psychrophilic iron superoxide dismutase from Pseudoalteromonas haloplanktis (PhSOD) is the presence in its amino acid sequence of a reactive cysteine (Cys57). To define the role of this residue, a structural characterization of the effect of two PhSOD mutations, C57S and C57R, was performed. Thermal and denaturant-induced unfolding of wild type and mutant PhSOD followed by circular dichroism and fluorescence studies revealed that C→R substitution alters the thermal stability and the resistance against denaturants of the enzyme, whereas C57S only alters the stability of the protein against urea. The crystallographic data on the C57R mutation suggest an involvement of the Arg side chain in the formation of salt bridges on protein surface. These findings support the hypothesis that the thermal resistance of PhSOD relies on optimization of charge-charge interactions on its surface. Our study contributes to a deeper understanding of the denaturation mechanism of superoxide dismutases, suggesting the presence of a structural dimeric intermediate between the native state and the unfolded state. This hypothesis is supported by the crystalline and solution data on the reduced form of the enzyme.


    Organizational Affiliation

    Dipartimento di Scienze Chimiche, Università di Napoli "Federico II", Complesso Universitario di Monte Sant'Angelo, I-80126 Napoli, Italy; Istituto di Biostrutture e Bioimmagini, CNR, Via Mezzocannone 16, I-80134 Napoli, Italy.




Macromolecules

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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Superoxide dismutase [Fe]
A, B
192Pseudoalteromonas haloplanktis (strain TAC 125)Mutation(s): 1 
Gene Names: sodB
EC: 1.15.1.1
Find proteins for P84612 (Pseudoalteromonas haloplanktis (strain TAC 125))
Go to UniProtKB:  P84612
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FE
Query on FE

Download SDF File 
Download CCD File 
A, B
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.06 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.190 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 45.622α = 90.00
b = 103.736β = 108.29
c = 50.244γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data reduction
CNSrefinement
PHASESphasing
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-02-26
    Type: Initial release