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Names | |
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Preferred IUPAC name (9R)-1-[(2R,3S,4R,5R)-5-(6-Amino-9H-purin-9-yl)-4-hydroxy-3-(phosphonooxy)oxolan-2-yl]-3,5,9-trihydroxy-3,5,10,14,19-pentaoxo-8,8-dimethyl-2,4,6-trioxa-18-thia-11,15-diaza-3λ5,5λ5-diphosphahenicosan-21-oic acid | |
Identifiers | |
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ChemSpider | |
ECHA InfoCard | 100.007.596 |
MeSH | Malonyl+CoA |
PubChem CID | |
UNII |
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CompTox Dashboard (EPA) | |
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Properties | |
C24H38N7O19P3S | |
Molar mass | 853.582 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Malonyl-CoA is a coenzyme A derivative of malonic acid.
Malonyl-CoA cannot cross membranes and there is no known malonyl-CoA import mechanism. [1] [2] The biosynthesis therefore takes place locally:
It plays a key role in chain elongation in fatty acid biosynthesis and polyketide biosynthesis.
Malonyl-CoA provides 2-carbon units to fatty acids and commits them to fatty acid chain synthesis.
Malonyl-CoA is utilised in fatty acid biosynthesis by the enzyme malonyl coenzyme A:acyl carrier protein transacylase (MCAT). MCAT serves to transfer malonate from malonyl-CoA to the terminal thiol of holo-acyl carrier protein (ACP).
Malonyl-CoA is a highly regulated molecule in fatty acid synthesis; as such, it inhibits the rate-limiting step in beta-oxidation of fatty acids. [6] Malonyl-CoA inhibits fatty acids from associating with carnitine by regulating the enzyme carnitine palmitoyltransferase, thereby preventing them from entering the mitochondria, where fatty acid oxidation and degradation occur.
MCAT is also involved in bacterial polyketide biosynthesis. The enzyme MCAT together with an acyl carrier protein (ACP), and a polyketide synthase (PKS) and chain-length factor heterodimer, constitutes the minimal PKS of type II polyketides.
Malonyl-CoA plays a special role in the mitochondrial clearance of toxic malonic acid in the metabolic disorders combined malonic and methylmalonic aciduria (CMAMMA) and malonic aciduria. [6] In CMAMMA, malonyl-CoA synthetase, ACSF3 is impaired, which generates mitochondrial malonyl-CoA from malonic acid, which can then be converted to acetyl-CoA by malonyl-CoA decarboxylase. [5] [6] In contrast, in malonic aciduria, malonyl-CoA decarboxylase is decreased, which converts malonyl-CoA to acetyl-CoA. [6]