DGTPase
Deoxyguanosinetriphosphate triphosphohydrolase (dGTPase) is a triphosphohydrolase that has a preference for dGTP over other dNTPs, they hydrolase dGTP to form deoxyguanosine and triphosphate. Escherichia coli dGTPase (Dgt) has been shown to have a strong single-stranded DNA-binding (ssDNA) activity [PMID:25694425] which is thought to act as an allosteric regulator.
Reference Protein and Structure
- Sequence
-
P15723
(3.1.5.1)
(Sequence Homologues)
(PDB Homologues)
- Biological species
-
Escherichia coli K-12 (Bacteria)
- PDB
-
4x9e
- DEOXYGUANOSINETRIPHOSPHATE TRIPHOSPHOHYDROLASE from Escherichia coli with two DNA effector molecules
(3.1 Å)
- Catalytic CATH Domains
-
1.10.3210.10
(see all for 4x9e)
- Cofactors
- Magnesium(2+) (1)
Enzyme Reaction (EC:3.1.5.1)
+
→
+
+
Alternative enzyme names: Deoxy-GTPase, Deoxyguanosine 5-triphosphate triphosphohydrolase, Deoxyguanosine triphosphatase, Deoxyguanosine triphosphate triphosphohydrolase, Deoxyguanosinetriphosphate triphosphohydrolase,
Enzyme Mechanism
Introduction
The mechanism for this protein has not yet been elucidated.
Catalytic Residues Roles
| UniProt | PDB* (4x9e) | ||
| His69, Asp268, Asp118, His117 | His69A, Asp268A, Asp118A, His117A | Forms part of the magnesium binding site. | metal ligand |
| Arg442 | Arg442B | The exact role of this residue is unknown at this time. It is interesting because after DNA binding, it moved closer to the dGTP substrate, which is likely to affect the positioning of the substrate. | unknown |
*PDB label guide - RESx(y)B(C) - RES: Residue Name; x: Residue ID in PDB file;
y: Residue ID in PDB sequence if different from PDB file; B: PDB Chain;
C: Biological Assembly Chain if different from PDB. If label is "Not Found" it means this residue is not found in the reference PDB.
Chemical Components
References
- Singh D et al. (2015), J Biol Chem, 290, 10418-10429. Structure of Escherichia coli dGTP triphosphohydrolase: a hexameric enzyme with DNA effector molecules. DOI:10.1074/jbc.M115.636936. PMID:25694425.
- Seto D et al. (1988), J Biol Chem, 263, 1494-1499. The purification and properties of deoxyguanosine triphosphate triphosphohydrolase from Escherichia coli. PMID:2826481.
Catalytic Residues Roles
| Residue | Roles |
|---|---|
| His69A | metal ligand |
| His117A | metal ligand |
| Asp118A | metal ligand |
| Asp268A | metal ligand |
| Arg442B | unknown |