1ZUQ

Contribution to Structure and Catalysis of Tyrosine 34 in Human Manganese Superoxide Dismutase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.235 
  • R-Value Observed: 0.235 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Contribution of human manganese superoxide dismutase tyrosine 34 to structure and catalysis.

Perry, J.J.Hearn, A.S.Cabelli, D.E.Nick, H.S.Tainer, J.A.Silverman, D.N.

(2009) Biochemistry 48: 3417-3424

  • DOI: 10.1021/bi8023288
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Superoxide dismutase (SOD) enzymes are critical in controlling levels of reactive oxygen species (ROS) that are linked to aging, cancer, and neurodegenerative disease. Superoxide (O(2)(*-)) produced during respiration is removed by the product of the ...

    Superoxide dismutase (SOD) enzymes are critical in controlling levels of reactive oxygen species (ROS) that are linked to aging, cancer, and neurodegenerative disease. Superoxide (O(2)(*-)) produced during respiration is removed by the product of the SOD2 gene, the homotetrameric manganese superoxide dismutase (MnSOD). Here, we examine the structural and catalytic roles of the highly conserved active-site residue Tyr34, based upon structure-function studies of MnSOD enzymes with mutations at this site. Substitution of Tyr34 with five different amino acids retained the active-site protein structure and assembly but caused a substantial decrease in the catalytic rate constant for the reduction of superoxide. The rate constant for formation of the product inhibition complex also decreases but to a much lesser extent, resulting in a net increase in the level of product inhibited form of the mutant enzymes. Comparisons of crystal structures and catalytic rates also suggest that one mutation, Y34V, interrupts the hydrogen-bonded network, which is associated with a rapid dissociation of the product-inhibited complex. Notably, with three of the Tyr34 mutants, we also observe an intermediate in catalysis, which has not been reported previously. Thus, these mutants establish a means of trapping a catalytic intermediate that promises to help elucidate the mechanism of catalysis.


    Organizational Affiliation

    Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA. jjperry@scripps.edu



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Superoxide dismutaseA, B198Homo sapiensMutation(s): 1 
Gene Names: SOD2
EC: 1.15.1.1
Find proteins for P04179 (Homo sapiens)
Explore P04179 
Go to UniProtKB:  P04179
NIH Common Fund Data Resources
PHAROS  P04179
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MN
Query on MN

Download CCD File 
A, B
MANGANESE (II) ION
Mn
WAEMQWOKJMHJLA-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.235 
  • R-Value Observed: 0.235 
  • Space Group: P 61 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 79.626α = 90
b = 79.626β = 90
c = 241.612γ = 120
Software Package:
Software NamePurpose
HKL-2000data collection
SCALEPACKdata scaling
AMoREphasing
CNSrefinement
HKL-2000data reduction

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-05-02
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance