In enzymology, a GTP diphosphokinase (EC 2.7.6.5) is an enzyme that catalyzes the chemical reaction
| GTP diphosphokinase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 2.7.6.5 | ||||||||
| CAS no. | 63690-89-1 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
- ATP + GTP AMP + guanosine 3'-diphosphate 5'-triphosphate
Thus, the two substrates of this enzyme are ATP and GTP, whereas its two products are AMP and guanosine 3'-diphosphate 5'-triphosphate.
This enzyme belongs to the family of transferases, specifically those transferring two phosphorus-containing groups (diphosphotransferases). The systematic name of this enzyme class is ATP:GTP 3'-diphosphotransferase. Other names in common use include stringent factor, guanosine 3',5'-polyphosphate synthase, GTP pyrophosphokinase, ATP-GTP 3'-diphosphotransferase, guanosine 5',3'-polyphosphate synthetase, (p)ppGpp synthetase I, (p)ppGpp synthetase II, guanosine pentaphosphate synthetase, GPSI, and GPSII. This enzyme participates in purine metabolism.
Structural studies
editAs of late 2007, 4 structures have been solved for this class of enzymes, with PDB accession codes 1E3H, 1E3P, 1VJ7, and 2BE3.
References
edit- Fehr S, Richter D (1981). "Stringent response of Bacillus stearothermophilus: evidence for the existence of two distinct guanosine 3',5'-polyphosphate synthetases". J. Bacteriol. 145 (1): 68–73. doi:10.1128/JB.145.1.68-73.1981. PMC 217245. PMID 6161916.
- Sy J, Akers H (1976). "Purification and properties of guanosine 5', 3'-polyphosphate synthetase from Bacillus brevis". Biochemistry. 15 (20): 4399–403. doi:10.1021/bi00665a008. PMID 184817.
