Fatty acid desaturase 2 (FADS2) is an
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
that in humans is encoded by the ''FADS2''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Function
The protein encoded by the FADS2 gene is a member of the
fatty acid desaturase
Fatty acid desaturases (also called unsaturases) are a family of enzymes that convert saturated fatty acids into unsaturated fatty acids and polyunsaturated fatty acids. For the common fatty acids of the C18 variety, desaturases convert stearic ...
(FADS) gene family and desaturates omega-3 and omega-6 polyunsaturated fatty acids at the delta-6 position, catalyzing the first and rate-limiting step in the formation of tetracosapentaenoic acid and
tetracosahexaenoic acid. Despite the name, it was also shown to catalyze some delta-8 and delta-4 desaturation reactions. Desaturase enzymes (such as those encoded by FADS2) cause desaturation of
fatty acid
In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated and unsaturated compounds#Organic chemistry, saturated or unsaturated. Most naturally occurring fatty acids have an ...
s through the introduction of double bonds between defined carbons of the fatty acyl chain. FADS family members are considered fusion products composed 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 amin ...
cytochrome b5
Cytochromes ''b''5 are ubiquitous electron transport hemoproteins found in animals, plants, fungi and purple bacteria, purple phototrophic bacteria. The microsome, microsomal and mitochondrial variants are membrane-bound, while bacterial and tho ...
-like domain and a
C-terminal
The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, carboxy tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When t ...
multiple membrane-spanning desaturase portion, both of which are characterized by conserved
histidine
Histidine (symbol His or H) is an essential amino acid that is used in the biosynthesis of proteins. It contains an Amine, α-amino group (which is in the protonated –NH3+ form under Physiological condition, biological conditions), a carboxylic ...
motifs. This gene is clustered with family members
FADS1 and FADS2 at 11q12-q13.1; this cluster is thought to have arisen evolutionarily from gene duplication based on its similar exon/intron organization.
Clinical significance
It was reported the ''FADS2'' interacts with
breastfeeding
Breastfeeding, also known as nursing, is the process where breast milk is fed to a child. Infants may suck the milk directly from the breast, or milk may be extracted with a Breast pump, pump and then fed to the infant. The World Health Orga ...
such that breast-fed children with the "C" version of the gene appear about 7
intelligence quotient
An intelligence quotient (IQ) is a total score derived from a set of standardized tests or subtests designed to assess human intelligence. Originally, IQ was a score obtained by dividing a person's mental age score, obtained by administering ...
(IQ) points higher than those with the less common "G" version (less than this when adjusted for maternal IQ).
Gene governs IQ boost from breastfeeding
References
Further reading
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EC 1.14.19