Carboxy-lyases, also known as decarboxylases, are carbon–carbon lyases that add or remove a carboxyl group from organic compound

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

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These enzyme

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...

s catalyze the decarboxylation of amino acids, beta-keto acids and alpha-keto acidshttp://www.expasy.org/cgi-bin/get-entries?KW=Decarboxylase.

Classification and nomenclature

Carboxy-lyases are categorized under EC number

EC number

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

 4.1.1. http://www.biochem.ucl.ac.uk/bsm/enzymes/ec4/ec01/ec01/index.html
Usually, they are named after the substrate whose decarboxylation

Decarboxylation

Decarboxylation is a chemical reaction that releases carbon dioxide . Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is the first chemical step in photosynthesis, is called carbonation, the addition of CO2 to...

 they catalyze, for example Pyruvate decarboxylase

Pyruvate decarboxylase

Not to be confused with pyruvate dehydrogenase, the enzyme which catalyses the link reaction.Pyruvate decarboxylase is a homotetrameric enzyme that catalyses the decarboxylation of pyruvic acid to acetaldehyde and carbon dioxide in the cytoplasm. It is also called 2-oxo-acid carboxylase,...

 catalyzes the decarboxylation of Pyruvate

Examples

• Aromatic-L-amino-acid decarboxylase
• Glutamate decarboxylase
  Glutamate decarboxylase
  Glutamate decarboxylase or glutamic acid decarboxylase is an enzyme that catalyzes the decarboxylation of glutamate to GABA and CO2. GAD uses PLP as a cofactor. The reaction proceeds as follows:...
  
  
• Histidine decarboxylase
  Histidine decarboxylase
  Histidine decarboxylase is the enzyme that catalyzes the reaction that produces histamine from histidine with the help of vitamin B6 as follows:C6H9N3O2 → C5H9N3 + CO2...
  
  
• Ornithine decarboxylase
  Ornithine decarboxylase
  The enzyme ornithine decarboxylase catalyzes the decarboxylation of ornithine to form putrescine. This reaction is the committed step in polyamine synthesis. In humans, this protein has 461 amino acids and forms a homodimer....
  
  
• Phosphoenolpyruvate carboxylase
  Phosphoenolpyruvate carboxylase
  Phosphoenolpyruvate carboxylase is an enzyme in the family of carboxy-lyases that catalyzes the addition of bicarbonate to phosphoenolpyruvate to form the four-carbon compound oxaloacetate:This reaction is used for carbon fixation in so-called "CAM" and "C4" plants where it plays a key role in...
  
  
• Pyruvate decarboxylase
  Pyruvate decarboxylase
  Not to be confused with pyruvate dehydrogenase, the enzyme which catalyses the link reaction.Pyruvate decarboxylase is a homotetrameric enzyme that catalyses the decarboxylation of pyruvic acid to acetaldehyde and carbon dioxide in the cytoplasm. It is also called 2-oxo-acid carboxylase,...
  
  
• RuBisCO
  RuBisCO
  Ribulose-1,5-bisphosphate carboxylase oxygenase, commonly known by the shorter name RuBisCO, is an enzyme involved in the first major step of carbon fixation, a process by which atmospheric carbon dioxide is converted by plants to energy-rich molecules such as glucose. RuBisCo is an abbreviation...
  
   – the only carboxylase that leads to a net fixation of carbon dioxide
• Uridine monophosphate synthetase
  Uridine monophosphate synthetase
  Uridine monophosphate synthetase is the enzyme that catalyses the formation of uridine monophosphate , an energy-carrying molecule in many important biosynthetic pathways...
  
  
• Uroporphyrinogen III decarboxylase
  Uroporphyrinogen III decarboxylase
  Uroporphyrinogen decarboxylase, also known as UROD, is an enzyme that in humans is encoded by the UROD gene.- Function :This gene encodes the fifth enzyme of the heme biosynthetic pathway...
  
  

See also

• Enzyme
  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...
  
  s
• Lyase
  Lyase
  In biochemistry, a lyase is an enzyme that catalyzes the breaking of various chemical bonds by means other than hydrolysis and oxidation, often forming a new double bond or a new ring structure...
  
  s
• List of EC numbers of enzymes belonging to category EC 4.1