Phosphotransferase
Class of enzymes
Phosphotransferases are a category of enzymes ( EC number 2.7) that catalyze phosphorylation reactions. The general form of the reactions they catalyze is:
-
A-P + B
B-P + A
Where P is a phosphate group and A and B are the donating and accepting molecules, respectively.
Classification
Phosphotransferases are generally classified according to the acceptor molecule. [1]
- EC 2.7.1 Phosphotransferases with an alcohol group as acceptor
- EC 2.7.2 Phosphotransferases with a carboxy group as acceptor
- EC 2.7.3 Phosphotransferases with a nitrogenous group as acceptor
- EC 2.7.4 Phosphotransferases with a phosphate group as acceptor
- EC 2.7.9 Phosphotransferases with paired acceptors. In these reactions, a single triphosphate-nucleotide transfers two phosphates to two different acceptor molecules, resulting in a monophosphate-nucleotide and two phosphorylated products.
Phosphotransferase system
The phosphotransferase system (PTS) is a complex group translocation system present in many bacteria. The PTS transports sugars (such as glucose , mannose , and mannitol ) into the cell. The first step of this reaction is phosphorylation of the substrate via phosphotransferase during transport. In the case of glucose, the product of this phosphorylation is glucose-6-phosphate (Glc-6P). Due to the negative charge of the phosphate, this Glc-6P can no longer freely leave the cell. This is the first reaction of glycolysis , which degrades the sugar to pyruvate .
See also
References
- ↑ Archived 2015-10-13 at the Wayback Machine , Classification in this article follows the rules of Enzyme Nomenclature of the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB).
External links
- Phosphotransferases at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
Activity | |
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Regulation | |
Classification | |
Kinetics | |
Types |
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2.7.1-2.7.4:
phosphotransferase / kinase ( PO 4 ) |
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2.7.6
:
diphosphotransferase
( P 2 O 7 ) |
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2.7.7
:
nucleotidyltransferase
( PO 4 -nucleoside ) |
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2.7.8 : miscellaneous |
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2.7.10-2.7.13:
protein kinase
( PO 4 ; protein acceptor) |
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