PDBsum entry 3k91

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Oxidoreductase PDB id
Protein chains
148 a.a. *
128 a.a. *
Waters ×255
* Residue conservation analysis
PDB id:
Name: Oxidoreductase
Title: Polysulfane bridge in cu-zn superoxide dismutase
Structure: Superoxide dismutase [cu-zn]. Chain: a, b. Engineered: yes. Mutation: yes
Source: Homo sapiens. Human. Organism_taxid: 9606. Gene: sod1. Expressed in: saccharomyces cerevisiae. Expression_system_taxid: 4932.
1.75Å     R-factor:   0.189     R-free:   0.218
Authors: Z.You,X.Cao,A.B.Taylor,P.J.Hart,R.L.Levine
Key ref: Z.You et al. (2010). Characterization of a covalent polysulfane bridge in copper-zinc superoxide dismutase . Biochemistry, 49, 1191-1198. PubMed id: 20052996
15-Oct-09     Release date:   19-Jan-10    
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Protein chain
Pfam   ArchSchema ?
P00441  (SODC_HUMAN) -  Superoxide dismutase [Cu-Zn]
154 a.a.
148 a.a.*
Protein chain
Pfam   ArchSchema ?
P00441  (SODC_HUMAN) -  Superoxide dismutase [Cu-Zn]
154 a.a.
128 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 4 residue positions (black crosses)

 Enzyme reactions 
   Enzyme class: Chains A, B: E.C.  - Superoxide dismutase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: 2 superoxide + 2 H+ = O2 + H2O2
2 × superoxide
+ 2 × H(+)
= O(2)
+ H(2)O(2)
      Cofactor: Fe cation or Mn(2+) or (Zn(2+) and Cu cation)
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     extracellular region   20 terms 
  Biological process     cellular response to potassium ion   66 terms 
  Biochemical function     antioxidant activity     13 terms  


    Added reference    
Biochemistry 49:1191-1198 (2010)
PubMed id: 20052996  
Characterization of a covalent polysulfane bridge in copper-zinc superoxide dismutase .
Z.You, X.Cao, A.B.Taylor, P.J.Hart, R.L.Levine.
In the course of studies on human copper-zinc superoxide dismutase (SOD1), we observed a modified form of the protein whose mass was increased by 158 mass units. The covalent modification was characterized, and we established that it is a novel heptasulfane bridge connecting the two Cys111 residues in the SOD1 homodimer. The heptasulfane bridge was visualized directly in the crystal structure of a recombinant human mutant SOD1, H46R/H48Q, produced in yeast. The modification is reversible, with the bridge being cleaved by thiols, by cyanide, and by unfolding of the protein to expose the polysulfane. The polysulfane bridge can be introduced in vitro by incubation of purified SOD1 with elemental sulfur, even under anaerobic conditions and in the presence of a metal chelator. Because polysulfanes and polysulfides can catalyze the generation of reactive oxygen and sulfur species, the modification may endow SOD1 with a toxic gain of function.

Literature references that cite this PDB file's key reference

  PubMed id Reference
21303647 J.I.Toohey (2011).
Sulfur signaling: is the agent sulfide or sulfane?
  Anal Biochem, 413, 1-7.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time.