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PDBsum entry 2c3t

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protein Protein-protein interface(s) links
Transferase PDB id
2c3t
Jmol
Contents
Protein chain
239 a.a. *
Waters ×267
* Residue conservation analysis
PDB id:
2c3t
Name: Transferase
Title: Human glutathione-s-transferase t1-1, w234r mutant, apo form
Structure: Glutathione s-transferase theta 1. Chain: a, b, c, d. Synonym: human glutathione transferase t1-1, gst class- theta 1. Engineered: yes. Mutation: yes
Source: Homo sapiens. Human. Organism_taxid: 9606. Expressed in: escherichia coli. Expression_system_taxid: 562.
Biol. unit: Dimer (from PDB file)
Resolution:
2.4Å     R-factor:   0.216     R-free:   0.267
Authors: K.Tars,A.-K.Larsson,A.Shokeer,B.Olin,B.Mannervik, G.J.Kleywegt
Key ref:
K.Tars et al. (2006). Structural basis of the suppressed catalytic activity of wild-type human glutathione transferase T1-1 compared to its W234R mutant. J Mol Biol, 355, 96. PubMed id: 16298388 DOI: 10.1016/j.jmb.2005.10.049
Date:
12-Oct-05     Release date:   30-Nov-05    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chains
Pfam   ArchSchema ?
P30711  (GSTT1_HUMAN) -  Glutathione S-transferase theta-1
Seq:
Struc:
240 a.a.
239 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.2.5.1.18  - Glutathione transferase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: RX + glutathione = HX + R-S-glutathione
RX
+ glutathione
= 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     small molecule metabolic process   7 terms 
  Biochemical function     transferase activity     3 terms  

 

 
    reference    
 
 
DOI no: 10.1016/j.jmb.2005.10.049 J Mol Biol 355:96 (2006)
PubMed id: 16298388  
 
 
Structural basis of the suppressed catalytic activity of wild-type human glutathione transferase T1-1 compared to its W234R mutant.
K.Tars, A.K.Larsson, A.Shokeer, B.Olin, B.Mannervik, G.J.Kleywegt.
 
  ABSTRACT  
 
The crystal structures of wild-type human theta class glutathione-S-transferase (GST) T1-1 and its W234R mutant, where Trp234 was replaced by Arg, were solved both in the presence and absence of S-hexyl-glutathione. The W234R mutant was of interest due to its previously observed enhanced catalytic activity compared to the wild-type enzyme. GST T1-1 from rat and mouse naturally contain Arg in position 234, with correspondingly high catalytic efficiency. The overall structure of GST T1-1 is similar to that of GST T2-2, as expected from their 53% sequence identity at the protein level. Wild-type GST T1-1 has the side-chain of Trp234 occupying a significant portion of the active site. This bulky residue prevents efficient binding of both glutathione and hydrophobic substrates through steric hindrance. The wild-type GST T1-1 crystal structure, obtained from co-crystallization experiments with glutathione and its derivatives, showed no electron density for the glutathione ligand. However, the structure of GST T1-1 mutant W234R showed clear electron density for S-hexyl-glutathione after co-crystallization. In contrast to Trp234 in the wild-type structure, the side-chain of Arg234 in the mutant does not occupy any part of the substrate-binding site. Instead, Arg234 is pointing in a different direction and, in addition, interacts with the carboxylate group of glutathione. These findings explain our earlier observation that the W234R mutant has a markedly improved catalytic activity with most substrates tested to date compared to the wild-type enzyme. GST T1-1 catalyzes detoxication reactions as well as reactions that result in toxic products, and our findings therefore suggest that humans have gained an evolutionary advantage by a partially disabled active site.
 
  Selected figure(s)  
 
Figure 3.
Figure 3. Active site of GST T1-1. (a) The active site of the W234R mutant of GST T1-1 with bound GSHex is shown with the solvent-accessible surface of the enzyme. The hexyl group of GSHex is shown in black. The two active-site iodides are shown as spheres. The colors of the pocket surface reflect the nearest protein atom: blue-green, carbon; blue, nitrogen; red, oxygen; yellow, sulfur. (b) A close-up view of the hydrophobic binding pocket in two different orientations. The approximate positions of side-chains that lie around and below the ligand in each view are indicated. (c) Effect of replacing Trp234 with Arg. In the mutant W234R structure (yellow), Arg234 forms a salt-bridge (red dotted line) with the C-terminal carboxyl group of GSHex (green carbon atoms). In the wild-type structure (brown), Trp234 occupies a significant portion of the binding site, thus preventing GSH and the substrate from binding.
Figure 5.
Figure 5. Comparison of the polar interactions of GSH derivatives. (a) The human GST T1-1 W234R mutant and (b) human GST T2-2. The ligands actually bound were GSHex for mutant W234R and S-menaphthyl-glutathione for GST T2-2. Carbon atoms are shown in black, oxygen atoms in red, nitrogen atoms in blue and sulfur atom in yellow. Only direct polar protein-ligand interactions are shown; water-mediated hydrogen bonds and hydrophobic interactions are omitted. The only exception is the interaction of Thr104 from the B subunit of T1-1 to GSH via a water molecule. All other interacting residues are from the A subunit. An interaction similar to that of residue 104 (in GST T1-1) with GSH is largely conserved in GSTs. However, in most cases the interaction is direct, and involves an aspartate residue, like in GST T2-2. This Figure was created with LIGPLOT33 and modified manually.
 
  The above figures are reprinted by permission from Elsevier: J Mol Biol (2006, 355, 96-0) copyright 2006.  
  Figures were selected by the author.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
20022951 A.Shokeer, and B.Mannervik (2010).
Minor modifications of the C-terminal helix reschedule the favored chemical reactions catalyzed by theta class glutathione transferase T1-1.
  J Biol Chem, 285, 5639-5645.  
  20981235 P.D.Josephy (2010).
Genetic variations in human glutathione transferase enzymes: significance for pharmacology and toxicology.
  Hum Genomics Proteomics, 2010, 876940.  
19252342 N.Tatewaki, K.Maekawa, N.Katori, K.Kurose, N.Kaniwa, N.Yamamoto, H.Kunitoh, Y.Ohe, H.Nokihara, I.Sekine, T.Tamura, T.Yoshida, N.Saijo, Y.Saito, and J.Sawada (2009).
Genetic variations and haplotype structures of the glutathione S-transferase genes, GSTT1 and GSTM1, in a Japanese patient population.
  Drug Metab Pharmacokinet, 24, 118-126.  
16973661 M.Unal, M.Güven, K.Devrano─člu, A.Ozaydin, B.Batar, N.Tamçelik, E.E.Görgün, D.Uçar, and A.Sarici (2007).
Glutathione S transferase M1 and T1 genetic polymorphisms are related to the risk of primary open-angle glaucoma: a study in a Turkish population.
  Br J Ophthalmol, 91, 527-530.  
17587159 Y.Wu, J.Shen, and Z.Yin (2007).
Expression, purification and functional analysis of hexahistidine-tagged human glutathione S-transferase P1-1 and its cysteinyl mutants.
  Protein J, 26, 359-370.  
17011574 K.E.Griswold, N.S.Aiyappan, B.L.Iverson, and G.Georgiou (2006).
The evolution of catalytic efficiency and substrate promiscuity in human theta class 1-1 glutathione transferase.
  J Mol Biol, 364, 400-410.  
16948056 P.D.Josephy, P.L.Taylor, G.Vervaet, and B.Mannervik (2006).
Screening and characterization of variant Theta-class glutathione transferases catalyzing the activation of ethylene dibromide to a mutagen.
  Environ Mol Mutagen, 47, 657-665.  
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.