The Full Wiki

Coenzyme A: Wikis

Advertisements
  

Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.

Encyclopedia

From Wikipedia, the free encyclopedia

Coenzyme A
Coenzym A.svg
Coenzyme-A-3D-balls.png
Identifiers
CAS number 85-61-0 Yes check.svgY
PubChem 317
MeSH Coenzyme+A
SMILES
Properties
Molecular formula C21H36N7O16P3S
Molar mass 767.535
 Yes check.svgY (what is this?)  (verify)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Coenzyme A (CoA, CoASH, or HSCoA) is a coenzyme, notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the citric acid cycle. All sequenced genomes encode enzymes that use coenzyme A as a substrate and around 4% of cellular enzymes use it (or a thioester, such as acetyl-CoA) as a substrate. It is adapted from cysteamine, pantothenate, and adenosine triphosphate.

Contents

Biosynthesis

Coenzyme A is synthesized in a five-step process from pantothenate:

  1. Pantothenate (Vitamin B5) is phosphorylated to 4'-phosphopantothenate by the enzyme pantothenate kinase (PanK; CoaA; CoaX)
  2. A cysteine is added to 4'-phosphopantothenate by the enzyme phosphopantothenoylcysteine synthetase (PPC-DC; CoaB) to form 4'-phospho-N-pantothenoylcysteine (PPC)
  3. PPC is decarboxylated to 4'-phosphopantetheine by phosphopantothenoylcysteine decarboxylase (CoaC)
  4. 4'-phosphopantetheine is adenylylated to form dephospho-CoA by the enzyme phosphopantetheine adenylyl transferase (CoaD)
  5. Finally, dephospho-CoA is phosphorylated using ATP to coenzyme A by the enzyme dephosphocoenzyme A kinase (CoaE).

Function

Since coenzyme A is chemically a thiol, it can react with carboxylic acids to form thioesters, thus functioning as an acyl group carrier. It assists in transferring fatty acids from the cytoplasm to mitochondria. A molecule of coenzyme A carrying an acetyl group is also referred to as acetyl-CoA. When it is not attached to an acyl group it is usually referred to as 'CoASH' or 'HSCoA'.

List of coenzyme A activated acyl groups

Additional images

References

Advertisements

Simple English

Coenzyme A (CoA, CoASH, or HSCoA) is an enzyme used in making fatty acids and accepting chemicals in the Link reaction and Krebs cycle.

A molecule of coenzyme A carrying an acetyl group is caleld acetyl-CoA

Gallery

Error creating thumbnail: sh: convert: command not found
Wikimedia Commons has images, video, and/or sound related to:



Advertisements






Got something to say? Make a comment.
Your name
Your email address
Message