KEGG   ENZYME: 2.7.7.45Help
Entry
EC 2.7.7.45                 Enzyme                                 

Name
guanosine-triphosphate guanylyltransferase;
diguanosine tetraphosphate synthetase;
GTP-GTP guanylyltransferase;
Gp4G synthetase;
guanosine triphosphate-guanose triphosphate guanylyltransferase
Class
Transferases;
Transferring phosphorus-containing groups;
Nucleotidyltransferases
BRITE hierarchy
Sysname
GTP:GTP guanylyltransferase
Reaction(IUBMB)
2 GTP = diphosphate + P1,P4-bis(5'-guanosyl) tetraphosphate [RN:R00012]
Reaction(KEGG)
Substrate
GTP [CPD:C00044]
Product
diphosphate [CPD:C00013];
P1,P4-bis(5'-guanosyl) tetraphosphate [CPD:C01261]
Comment
Also acts, more slowly, on GDP to form P1,P3-bis(5'-guanosyl) triphosphate.
History
EC 2.7.7.45 created 1976
Reference
1  [PMID:4208243]
  Authors
Warner AH, Beers PC, Huang FL.
  Title
Biosynthesis of the diguanosine nucleotides. I. Purification and properties of an enzyme from yolk platelets of brine shrimp embryos.
  Journal
Can. J. Biochem. 52 (1974) 231-40.
  Organism
Artemia salina
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 
CAS: 
54576-89-5

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