Dikinases are a category of enzymes that catalyze

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...

ATP + X + Y AMP + X-P + Y-P.

Dikinases are all phosphotransferase

Phosphotransferase

Phosphotransferases are a category of enzymes that catalyze phosphorylation reactions. The general form of the reactions they catalyze is: A—P + B ⇔ B—P + A...

s. Their designated EC number

EC number

The Enzyme Commission number is a numerical classification scheme for enzymes, based on the chemical reactions they catalyze....

 is 2.7.9. It is one of the smallest groups of phosphotransferases.

Dikinases take two phosphate

Phosphate

A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...

 groups from ATP

Adenosine triphosphate

Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...

 and transfer

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...

 each one to a different acceptor. This results in AMP

Adenosine monophosphate

Adenosine monophosphate , also known as 5'-adenylic acid, is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid and the nucleoside adenosine. AMP consists of a phosphate group, the sugar ribose, and the nucleobase adenine...

 and two different phosphorylated

Phosphorylation

Phosphorylation is the addition of a phosphate group to a protein or other organic molecule. Phosphorylation activates or deactivates many protein enzymes....

 compounds. In most dikinases, one of the acceptors is water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

. In at least one dikinase (pyruvate, phosphate dikinase

Pyruvate, phosphate dikinase

In enzymology, a pyruvate, phosphate dikinase is an enzyme that catalyzes the chemical reactionThe 3 substrates of this enzyme are ATP, pyruvate, and phosphate, whereas its 3 products are AMP, phosphoenolpyruvate , and diphosphate...

), one of the acceptors is inorganic phosphate, resulting in diphosphate.

For the dikinases that use water as acceptor, it has been shown that the γ-phosphate of ATP (the third, most distant phosphate) is transferred to water, whereas the β-phosphate (the middle phosphate) is transferred to the other acceptor. It has also been shown that the enzyme first phosphorylates itself (autophosphorylation

Autophosphorylation

In biochemistry, autophosphorylation is the process in which a protein kinase attaches a phosphate group to itself. This usually lead to kinase activation or regulation, and phosphorylation of other kinase substrates....

). After transfer of the γ-phosphate to water, the β-phosphate is first transferred to a histidine

Histidine

Histidine Histidine, an essential amino acid, has a positively charged imidazole functional group. It is one of the 22 proteinogenic amino acids. Its codons are CAU and CAC. Histidine was first isolated by German physician Albrecht Kossel in 1896. Histidine is an essential amino acid in humans...

 residue

Residue (chemistry)

In chemistry, residue is the material remaining after a distillation or an evaporation, or to a portion of a larger molecule, such as a methyl group. It may also refer to the undesired byproducts of a reaction....

 on the enzyme, and later to the final acceptor.

Dikinases are commonly named as follows: first acceptor, second acceptor kinase. Examples:

• Phosphoglucan, water dikinase
  Phosphoglucan, water dikinase
  In enzymology, a phosphoglucan, water dikinase is an enzyme that catalyzes the chemical reactionThe 3 substrates of this enzyme are ATP, phospho-alpha-glucan, and H2O, whereas its 3 products are AMP, O-phospho-[phospho-alpha-glucan], and phosphate....
  
  ,
• Selenide, water dikinase
  Selenide, water dikinase
  In enzymology, a selenide, water dikinase is an enzyme that catalyzes the chemical reactionThe 3 substrates of this enzyme are ATP, selenide, and H2O, whereas its 3 products are AMP, selenophosphate, and phosphate....
  
  .

Dikinases should not be confused with diphosphotransferase

Diphosphotransferase

Diphosphotransferase are phosphotransferase enzymes which act upon pyrophosphate groups.They are classified under EC number 2.7.6....

s (EC 2.7.6), which are phosphotransferases which act upon pyrophosphate

Pyrophosphate

In chemistry, the anion, the salts, and the esters of pyrophosphoric acid are called pyrophosphates. Any salt or ester containing two phosphate groups is called a diphosphate. As a food additive, diphosphates are known as E450.- Chemistry :...

groups.