1ZA5

Q69H-FeSOD


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.199 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The Crucial Importance of Chemistry in the Structure-Function Link: Manipulating Hydrogen Bonding in Iron-Containing Superoxide Dismutase.

Yikilmaz, E.Rodgers, D.W.Miller, A.F.

(2006) Biochemistry 45: 1151-1161

  • DOI: 10.1021/bi051495d
  • Primary Citation of Related Structures:  2BKB

  • PubMed Abstract: 
  • Fe-containing superoxide dismutase's active site Fe is coordinated by a solvent molecule, whose protonation state is coupled to the Fe oxidation state. Thus, we have proposed that H-bonding between glutamine 69 and this solvent molecule can strongly ...

    Fe-containing superoxide dismutase's active site Fe is coordinated by a solvent molecule, whose protonation state is coupled to the Fe oxidation state. Thus, we have proposed that H-bonding between glutamine 69 and this solvent molecule can strongly influence the redox activity of the Fe in superoxide dismutase (SOD). We show here that mutation of this Gln to His subtly alters the active site structure but preserves 30% activity. In contrast, mutation to Glu otherwise preserves the active site structure but inactivates the enzyme. Thus, enzyme function correlates not with atom positions but with residue identity (chemistry), in this case. We observe strong destabilization of the Q69E-FeSOD oxidized state relative to the reduced state and intermediate destabilization of oxidized Q69H-FeSOD. Indeed, redox titrations indicate that mutation of Gln69 to His increases the reduction potential by 240 mV, whereas mutation to Glu appears to increase it by more than 660 mV. We find that this suffices to explain the mutants' loss of activity, although additional factors may also contribute. The strongly elevated reduction potential of Q69E-FeSOD may reflect reorganization of the active site H-bonding network, including possible reversal of the polarity of the key H-bond between residue 69 and coordinated solvent.


    Organizational Affiliation

    Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Superoxide dismutase [Fe]
A, B
192Escherichia coli (strain K12)Gene Names: sodB
EC: 1.15.1.1
Find proteins for P0AGD3 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AGD3
Small Molecules
Ligands 2 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
TRS
Query on TRS

Download SDF File 
Download CCD File 
A, B
2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
TRIS BUFFER
C4 H12 N O3
LENZDBCJOHFCAS-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.199 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 41.202α = 90.00
b = 84.921β = 108.37
c = 61.634γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
DENZOdata reduction
CNSphasing
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-03-14
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance