Malonyl CoA-acyl carrier protein transacylase, mitochondrial is an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
that in humans is encoded by the ''MCAT''
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
Function
The protein encoded by this gene is found exclusively in the
mitochondrion
A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used ...
, where it catalyzes the transfer of a
malonyl
Malonic acid (IUPAC systematic name: propanedioic acid) is a dicarboxylic acid with structure CH2(COOH)2. The ionized form of malonic acid, as well as its esters and salts, are known as malonates. For example, diethyl malonate is malonic acid's ...
group from malonyl-CoA to the mitochondrial acyl carrier protein. The encoded protein may be part of a
fatty acid synthase
Fatty acid synthase (FAS) is an enzyme that in humans is encoded by the ''FASN'' gene.
Fatty acid synthase is a multi-enzyme protein that catalyzes fatty acid synthesis. It is not a single enzyme but a whole enzymatic system composed of two iden ...
complex that is more like the type II prokaryotic and plastid complexes rather than the type I human cytosolic complex. Two transcript variants encoding different isoforms have been found for this gene.
Clinical significance
The enzyme encoded by the MCAT gene, along with other enzymes that regulate
Malonyl-CoA
Malonyl-CoA is a coenzyme A derivative of malonic acid.
Functions
It plays a key role in chain elongation in fatty acid biosynthesis and polyketide biosynthesis.
Fatty acid biosynthesis
Malonyl-CoA provides 2-carbon units to fatty acids and commi ...
concentration, have been shown to regulate levels such that malonyl-CoA concentration decreases in human muscle tissue when under exercise training. This enzyme specifically has increased activity under these conditions, as it is known to catabolize malonyl-CoA.
Interactions
The human Malonyl CoA-acel carrier protein
transacylase
Acyltransferase is a type of transferase enzyme that acts upon acyl groups.
Examples include:
* Glyceronephosphate O-acyltransferase
* Lecithin-cholesterol acyltransferase
*Long-chain-alcohol O-fatty-acyltransferase
In enzymology, a long-chain- ...
in human mitochondria associates with respiratory complex one, such that it interacts functionally with a mitochondrial
malonyltransferase Malonyltransferase can refer to:
* (acyl-carrier-protein) S-malonyltransferase
* Anthocyanin 5-O-glucoside 6-O-malonyltransferase
In enzymology, an anthocyanin 5-O-glucoside 6-O-malonyltransferase () is an enzyme that catalyzes the chemical rea ...
. Both species are encoded by nuclear genes, and their translocation into mitochondria is dependent on the presence of an
N-terminal
The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the ami ...
targeting sequence.
References
Further reading
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