PDBsum entry 1gn6

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Oxidoreductase PDB id
Protein chains
198 a.a. *
_FE ×4
Waters ×360
* Residue conservation analysis
PDB id:
Name: Oxidoreductase
Title: G152a mutant of mycobacterium tuberculosis iron-superoxide dismutase.
Structure: Superoxide dismutase. Chain: a, b, c, d. Engineered: yes. Mutation: yes
Source: Mycobacterium tuberculosis. Organism_taxid: 1773. Expressed in: mycobacterium vaccae. Expression_system_taxid: 1810
Biol. unit: Tetramer (from PDB file)
2.90Å     R-factor:   0.169    
Authors: K.A.Bunting,J.B.Cooper,S.Saward,P.T.Erskine,M.O.Badasso, S.P.Wood,Y.Zhang,D.B.Young
Key ref:
J.B.Cooper et al. (1996). X-ray structure analysis of an engineered Fe-superoxide dismutase Gly-Ala mutant with significantly reduced stability to denaturant. FEBS Lett, 387, 105-108. PubMed id: 8674528 DOI: 10.1016/0014-5793(96)00490-5
03-Oct-01     Release date:   05-Oct-01    
Go to PROCHECK summary

Protein chains
P9WGE6  (SODF_MYCTO) -  Superoxide dismutase [Fe]
207 a.a.
198 a.a.*
Key:    Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 Enzyme reactions 
   Enzyme class: 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   1 term 
  Biological process     oxidation-reduction process   3 terms 
  Biochemical function     oxidoreductase activity     3 terms  


    Added reference    
DOI no: 10.1016/0014-5793(96)00490-5 FEBS Lett 387:105-108 (1996)
PubMed id: 8674528  
X-ray structure analysis of an engineered Fe-superoxide dismutase Gly-Ala mutant with significantly reduced stability to denaturant.
J.B.Cooper, S.Saward, P.T.Erskine, M.O.Badasso, S.P.Wood, Y.Zhang, D.Young.
We have refined the X-ray structure of a site-directed G152A mutant of the iron-dependent superoxide dismutase from Mycobacterium tuberculosis at 2.9 angstroms resolution. The mutation which replaces a glycine residue in a surface loop with alanine was designed to alter the conformation of this loop region which has previously been shown to play a crucial structural role in quaternary interactions within the SOD tetramer. Gly-152 was targeted as it has dihedral angles (phi = 83.1 degrees, psi = -0.3 degrees) close to the left-handed alpha-helical conformation which is rarely adopted by other amino acids except asparagine. Gly-152 was replaced by alanine as it has similar size and polarity, yet has a very low tendency to adopt similar conformations. X-ray data collection on crystals of this mutant at 2.9 angstroms resolution and subsequent least-squares refinement to an R-value of 0.169 clearly establish that the loop conformation is unaffected. Fluorescence studies of guanidine hydrochloride denaturation establish that the mutant is 4 kcal/mol less stable than the wild-type enzyme. Our results indicate that strict conformational constraints imposed upon a region of polypeptide, due for example to interactions with a neighbouring subunit, may force an alanine residue to adopt this sterically hindered conformation with a consequent reduction in stability of the folded conformation.
  Selected figure(s)  
Figure 1.
Fig. 1. A ribbon diagra of the tertiary structure of the superoxide dismutase from Mycobacterium tuberculosis. The helical hairpin in the N-terminal domain and the 144-152 loop region in the -ter- minal domain, both of which play crucial oles in he dimer-dimer interactions, are indicated.
Figure 4.
Fig. 4. A graph of AGe versus [Gu.HCI] for the wild-type (solid line +) and GI52A mutant (dashed line x) SOD. The vertical inter- cepts define the AGu ° values of 6.0 (+0.4) kcal/mol or wild-type enzyme and 1.7 ( + 0.3) kcal/mol or the mutant.
  The above figures are reprinted by permission from the Federation of European Biochemical Societies: FEBS Lett (1996, 387, 105-108) copyright 1996.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
17912757 R.Wintjens, D.Gilis, and M.Rooman (2008).
Mn/Fe superoxide dismutase interaction fingerprints and prediction of oligomerization and metal cofactor from sequence.
  Proteins, 70, 1564-1577.  
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