spacer
spacer

PDBsum entry 2z8i

Go to PDB code: 
protein ligands Protein-protein interface(s) links
Transferase PDB id
2z8i
Jmol
Contents
Protein chains
350 a.a. *
190 a.a. *
Ligands
AZS ×2
Waters ×473
* Residue conservation analysis
PDB id:
2z8i
Name: Transferase
Title: Crystal structure of escherichia coli gamma-glutamyltranspep complex with azaserine
Structure: Gamma-glutamyltranspeptidase. Chain: a, c. Fragment: large chain. Engineered: yes. Gamma-glutamyltranspeptidase. Chain: b, d. Fragment: small chain. Engineered: yes
Source: Escherichia coli. Organism_taxid: 562. Strain: k-12. Expressed in: escherichia coli. Expression_system_taxid: 562.
Resolution:
1.65Å     R-factor:   0.220     R-free:   0.236
Authors: K.Wada,M.Irie,K.Fukuyama
Key ref: K.Wada et al. (2008). Crystal structures of Escherichia coli gamma-glutamyltranspeptidase in complex with azaserine and acivicin: novel mechanistic implication for inhibition by glutamine antagonists. J Mol Biol, 380, 361-372. PubMed id: 18555071 DOI: 10.1016/j.jmb.2008.05.007
Date:
05-Sep-07     Release date:   24-Jun-08    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chains
Pfam   ArchSchema ?
P18956  (GGT_ECOLI) -  Gamma-glutamyltranspeptidase
Seq:
Struc:
 
Seq:
Struc:
580 a.a.
350 a.a.
Protein chains
Pfam   ArchSchema ?
P18956  (GGT_ECOLI) -  Gamma-glutamyltranspeptidase
Seq:
Struc:
 
Seq:
Struc:
580 a.a.
190 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Enzyme reactions 
   Enzyme class 2: Chains A, B, C, D: E.C.2.3.2.2  - Gamma-glutamyltransferase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: A (5-L-glutamyl)-peptide + an amino acid = a peptide + a 5-L-glutamyl amino acid
(5-L-glutamyl)-peptide
+
amino acid
Bound ligand (Het Group name = AZS)
matches with 45.45% similarity
= peptide
+ 5-L-glutamyl amino acid
   Enzyme class 3: Chains A, B, C, D: E.C.3.4.19.13  - Glutathione hydrolase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: Glutathione + H2O = L-cysteinylglycine + L-glutamate
Glutathione
+ H(2)O
= L-cysteinylglycine
+ L-glutamate
Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     glutathione metabolic process   1 term 
  Biochemical function     gamma-glutamyltransferase activity     1 term  

 

 
    reference    
 
 
DOI no: 10.1016/j.jmb.2008.05.007 J Mol Biol 380:361-372 (2008)
PubMed id: 18555071  
 
 
Crystal structures of Escherichia coli gamma-glutamyltranspeptidase in complex with azaserine and acivicin: novel mechanistic implication for inhibition by glutamine antagonists.
K.Wada, J.Hiratake, M.Irie, T.Okada, C.Yamada, H.Kumagai, H.Suzuki, K.Fukuyama.
 
  ABSTRACT  
 
gamma-Glutamyltranspeptidase (GGT) catalyzes the cleavage of such gamma-glutamyl compounds as glutathione, and the transfer of their gamma-glutamyl group to water or to other amino acids and peptides. GGT is involved in a number of biological phenomena such as drug resistance and metastasis of cancer cells by detoxification of xenobiotics. Azaserine and acivicin are classical and irreversible inhibitors of GGT, but their binding sites and the inhibition mechanisms remain to be defined. We have determined the crystal structures of GGT from Escherichia coli in complex with azaserine and acivicin at 1.65 A resolution. Both inhibitors are bound to GGT at its substrate-binding pocket in a manner similar to that observed previously with the gamma-glutamyl-enzyme intermediate. They form a covalent bond with the O(gamma) atom of Thr391, the catalytic residue of GGT. Their alpha-carboxy and alpha-amino groups are recognized by extensive hydrogen bonding and charge interactions with the residues that are conserved among GGT orthologs. The two amido nitrogen atoms of Gly483 and Gly484, which form the oxyanion hole, interact with the inhibitors directly or via a water molecule. Notably, in the azaserine complex the carbon atom that forms a covalent bond with Thr391 is sp(3)-hybridized, suggesting that the carbonyl of azaserine is attacked by Thr391 to form a tetrahedral intermediate, which is stabilized by the oxyanion hole. Furthermore, when acivicin is bound to GGT, a migration of the single and double bonds occurs in its dihydroisoxazole ring. The structural characteristics presented here imply that the unprecedented binding modes of azaserine and acivicin are conserved in all GGTs from bacteria to mammals and give a new insight into the inhibition mechanism of glutamine amidotransferases by these glutamine antagonists.