Guanosine-triphosphate guanylyltransferase
Encyclopedia
In enzymology, a guanosine-triphosphate guanylyltransferase is an enzyme
that catalyzes
the chemical reaction
Hence, this enzyme has one substrate
, GTP
, and two products
, diphosphate and P1,P4-bis(5'-guanosyl) tetraphosphate.
This enzyme belongs to the family of transferase
s, specifically those transferring phosphorus-containing nucleotide
groups (nucleotidyltransferase
s). The systematic name of this enzyme class is GTP:GTP guanylyltransferase. Other names in common use include diguanosine tetraphosphate synthetase, GTP-GTP guanylyltransferase, Gp4G synthetase, and guanosine triphosphate-guanose triphosphate guanylyltransferase.
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
that catalyzes
Catalysis
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....
the chemical reaction
Chemical reaction
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...
- 2 GTP
diphosphate + P1,P4-bis(5'-guanosyl) tetraphosphate
Hence, this enzyme has one substrate
Substrate (biochemistry)
In biochemistry, a substrate is a molecule upon which an enzyme acts. Enzymes catalyze chemical reactions involving the substrate. In the case of a single substrate, the substrate binds with the enzyme active site, and an enzyme-substrate complex is formed. The substrate is transformed into one or...
, GTP
Guanosine triphosphate
Guanosine-5'-triphosphate is a purine nucleoside triphosphate. It can act as a substrate for the synthesis of RNA during the transcription process...
, and two products
Product (chemistry)
Product are formed during chemical reactions as reagents are consumed. Products have lower energy than the reagents and are produced during the reaction according to the second law of thermodynamics. The released energy comes from changes in chemical bonds between atoms in reagent molecules and...
, diphosphate and P1,P4-bis(5'-guanosyl) tetraphosphate.
This enzyme belongs to the family of transferase
Transferase
In biochemistry, a transferase is an enzyme that catalyzes the transfer of a functional group from one molecule to another . For example, an enzyme that catalyzed this reaction would be a transferase:In this example, A would be the donor, and B would be the acceptor...
s, specifically those transferring phosphorus-containing nucleotide
Nucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
groups (nucleotidyltransferase
Nucleotidyltransferase
Nucleotidyltransferases are transferase enzymes of phosphorus-containing groups, e.g., substituents of nucleotidylic acids or simply nucleoside monophosphates...
s). The systematic name of this enzyme class is GTP:GTP guanylyltransferase. Other names in common use include diguanosine tetraphosphate synthetase, GTP-GTP guanylyltransferase, Gp4G synthetase, and guanosine triphosphate-guanose triphosphate guanylyltransferase.