CATH Classification
| Level | CATH Code | Description |
|---|---|---|
|
3 | Alpha Beta |
|
3.60 | 4-Layer Sandwich |
|
3.60.20 | Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1 |
|
3.60.20.40 | Gamma-glutamyltranspeptidase, small (S) subunit |
Domain Context
CATH Clusters
| Superfamily | 3.60.20.40 |
| Functional Family | Glutathione hydrolase 1 proenzyme |
Enzyme Information
| 2.3.2.2 |
Gamma-glutamyltransferase.
based on mapping to UniProt P19440
A (5-L-glutamyl)-peptide + an amino acid = a peptide + a 5-L-glutamyl amino acid.
-!- The mammlian enzyme is part of the cell antioxidant defense mechanism. -!- It initiates extracellular glutathione (GSH) breakdown, provides cells with a local cysteine supply and contributes to maintain intracelular GSH levels. -!- The protein also has EC 3.4.19.13 activity. -!- The enzyme consists of two chains that are created by the proteolytic cleavage of a single precursor polypeptide. -!- The N-terminal L-threonine of the C-terminal subunit functions as the active site for both the cleavage and the hydrolysis reactions.
|
| 3.4.19.14 |
Leukotriene-C(4) hydrolase.
based on mapping to UniProt P19440
Leukotriene C(4) + H(2)O = leukotriene D(4) + L-glutamate.
-!- The mouse enzyme is specific for leukotriene C(4), while the human enzyme also has considerable activity toward glutathione and oxidized glutathione (cf. EC 3.4.19.13).
|
| 3.4.19.13 |
Glutathione gamma-glutamate hydrolase.
based on mapping to UniProt P19440
(1) Glutathione + H(2)O = L-cysteinylglycine + L-glutamate. (2) A glutathione-S-conjugate + H(2)O = an (L-cysteinylglycine)-S- conjugate + L-glutamate.
-!- This is a bifunctional protein that also has the activity of EC 2.3.2.2. -!- The enzyme binds its substrate by forming an initial gamma-glutamyl- enzyme intermediate, releasing the L-cysteinylglycine part of the molecule. -!- The enzyme then reacts with either a water molecule or a different acceptor substrate (usually an L-amino acid or a dipeptide) to form L-glutamate or a product containing a new gamma-glutamyl isopeptide bond, respectively. -!- The enzyme acts on glutathione, glutathione-S-conjugates, and, at a lower level, on other substrates with an N-terminal L-gamma-glutamyl residue. -!- It plays a crucial part in the glutathione-mediated xenobiotic detoxification pathway. -!- The enzyme consists of two chains that are created by the proteolytic cleavage of a single precursor polypeptide.
|
UniProtKB Entries (1)
| P19440 |
GGT1_HUMAN
Homo sapiens
Glutathione hydrolase 1 proenzyme
|
PDB Structure
| PDB | 4ZCG |
| External Links | |
| Method | X-RAY DIFFRACTION |
| Organism | |
| Primary Citation |
Human gamma-Glutamyl Transpeptidase 1: STRUCTURES OF THE FREE ENZYME, INHIBITOR-BOUND TETRAHEDRAL TRANSITION STATES, AND GLUTAMATE-BOUND ENZYME REVEAL NOVEL MOVEMENT WITHIN THE ACTIVE SITE DURING CATALYSIS.
J.Biol.Chem.
|
