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PDBsum entry 3c3t

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protein ligands metals Protein-protein interface(s) links
Oxidoreductase PDB id
3c3t
Jmol
Contents
Protein chains
196 a.a. *
Ligands
SO4 ×2
Metals
_MN ×2
Waters ×175
* Residue conservation analysis
PDB id:
3c3t
Name: Oxidoreductase
Title: Role of a glutamate bridge spanning the dimeric interface of manganese superoxide dismutase
Structure: Superoxide dismutase [mn]. Chain: a, b. Fragment: unp residues 25-222. Engineered: yes. Mutation: yes
Source: Homo sapiens. Human. Organism_taxid: 9606. Gene: sod2. Expressed in: escherichia coli. Expression_system_taxid: 562.
Resolution:
2.20Å     R-factor:   0.175     R-free:   0.201
Authors: P.S.Quint,J.F.Domsic,D.E.Cabelli,R.Mckenna,D.N.Silverman
Key ref: P.S.Quint et al. (2008). Role of a glutamate bridge spanning the dimeric interface of human manganese superoxide dismutase. Biochemistry, 47, 4621-4628. PubMed id: 18373354 DOI: 10.1021/bi7024518
Date:
28-Jan-08     Release date:   22-Apr-08    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chains
Pfam   ArchSchema ?
P04179  (SODM_HUMAN) -  Superoxide dismutase [Mn], mitochondrial
Seq:
Struc:
222 a.a.
196 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 Enzyme reactions 
   Enzyme class: E.C.1.15.1.1  - 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!
  Biological process     oxidation-reduction process   2 terms 
  Biochemical function     superoxide dismutase activity     2 terms  

 

 
    Added reference    
 
 
DOI no: 10.1021/bi7024518 Biochemistry 47:4621-4628 (2008)
PubMed id: 18373354  
 
 
Role of a glutamate bridge spanning the dimeric interface of human manganese superoxide dismutase.
P.S.Quint, J.F.Domsic, D.E.Cabelli, R.McKenna, D.N.Silverman.
 
  ABSTRACT  
 
The function in the structure, stability, and catalysis of the interfaces between subunits in manganese superoxide dismutase (MnSOD) is currently under scrutiny. Glu162 in homotetrameric human MnSOD spans a dimeric interface and forms a hydrogen bond with His163 of an adjacent subunit which is a direct ligand of the manganese. We have examined the properties of two site-specific mutants of human MnSOD in which Glu162 is replaced with Asp (E162D) and Ala (E162A). The X-ray crystal structures of E162D and E162A MnSOD reveal no significant structural changes compared with the wild type other than the removal of the hydrogen bond interaction with His163 in E162A MnSOD. In the case of E162D MnSOD, an intervening solvent molecule fills the void created by the mutation to conserve the hydrogen bond interaction between His163 and residue 162. These mutants retain their tetrameric structure and their specificity for manganese over iron. Each has catalytic activity in the disproportionation of superoxide that is typically 5-25% of that of the wild-type enzyme and a level of product inhibition greater by approximately 2-fold. Differential scanning calorimetry indicates that the hydrogen bond between Glu162 and His163 contributes to the stability of MnSOD, with the major unfolding transition occurring at 81 degrees C for E162A compared to 90 degrees C for wild-type MnSOD. These results suggest that Glu162 at the tetrameric interface in human MnSOD supports stability and efficient catalysis and has a significant role in regulating product inhibition.
 

Literature references that cite this PDB file's key reference

  PubMed id Reference
20655193 J.Yu, L.Ge, S.Liu, P.Dai, S.Ge, and W.Zheng (2011).
Facile and scalable synthesis of a novel rigid artificial superoxide dismutase based on modified hollow mesoporous silica microspheres.
  Biosens Bioelectron, 26, 1936-1941.  
19788422 M.Grey, S.Yainoy, V.Prachayasittikul, and L.Bülow (2009).
A superoxide dismutase-human hemoglobin fusion protein showing enhanced antioxidative properties.
  FEBS J, 276, 6195-6203.  
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