PDBsum entry 3ktl

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Transferase PDB id
Protein chain
221 a.a. *
GTX ×2
Waters ×845
* Residue conservation analysis
PDB id:
Name: Transferase
Title: Crystal structure of an i71a human gsta1-1 mutant in complex hexylglutathione
Structure: Glutathione s-transferase a1. Chain: a, b. Synonym: gth1, ha subunit 1, gst-epsilon, gsta1-1, gst clas member 1. Engineered: yes. Mutation: yes
Source: Homo sapiens. Human. Organism_taxid: 9606. Gene: gsta1. Expressed in: escherichia coli. Expression_system_taxid: 469008.
1.75Å     R-factor:   0.211     R-free:   0.281
Authors: I.A.Achilonu,S.Gildenhuys,M.A.Fernandes,S.Fanucchi,H.W.Dirr
Key ref: I.Achilonu et al. (2010). The role of a topologically conserved isoleucine in glutathione transferase structure, stability and function. Acta Crystallogr Sect F Struct Biol Cryst Commun, 66, 776-780. PubMed id: 20606271
25-Nov-09     Release date:   22-Dec-09    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
P08263  (GSTA1_HUMAN) -  Glutathione S-transferase A1
222 a.a.
221 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.  - Glutathione transferase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: RX + glutathione = HX + R-S-glutathione
Bound ligand (Het Group name = GTX)
matches with 76.00% similarity
= HX
+ R-S-glutathione
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     cytoplasm   3 terms 
  Biological process     metabolic process   6 terms 
  Biochemical function     transferase activity     2 terms  


Acta Crystallogr Sect F Struct Biol Cryst Commun 66:776-780 (2010)
PubMed id: 20606271  
The role of a topologically conserved isoleucine in glutathione transferase structure, stability and function.
I.Achilonu, S.Gildenhuys, L.Fisher, J.Burke, S.Fanucchi, B.T.Sewell, M.Fernandes, H.W.Dirr.
The common fold shared by members of the glutathione-transferase (GST) family has a topologically conserved isoleucine residue at the N-terminus of helix 3 which is involved in the packing of helix 3 against two beta-strands in domain 1. The role of the isoleucine residue in the structure, function and stability of GST was investigated by replacing the Ile71 residue in human GSTA1-1 by alanine or valine. The X-ray structures of the I71A and I71V mutants resolved at 1.75 and 2.51 A, respectively, revealed that the mutations do not alter the overall structure of the protein compared with the wild type. Urea-induced equilibrium unfolding studies using circular dichroism and tryptophan fluorescence suggest that the mutation of Ile71 to alanine or valine reduces the stability of the protein. A functional assay with 1-chloro-2,4-dinitrobenzene shows that the mutation does not significantly alter the function of the protein relative to the wild type. Overall, the results suggest that conservation of the topologically conserved Ile71 maintains the structural stability of the protein but does not play a significant role in catalysis and substrate binding.