Polypeptide N-acetylgalactosaminyltransferase 3 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 ''GALNT3''
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 ...
.
This gene encodes UDP-GalNAc transferase 3, a member of the
polypeptide GalNAc transferase (GalNAc-T) family. This family transfers an
N-acetyl galactosamine to the
hydroxyl group
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...
of a
serine
Serine
(symbol Ser or S) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α- amino group (which is in the protonated − form under biological conditions), a carboxyl group (which is in the deprotonated − ...
or
threonine
Threonine (symbol Thr or T) is an amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH form when dissolved in water), a carboxyl group (which is in the deprotonated −COO− ...
residue in the first step of ''O''-linked oligosaccharide biosynthesis. Individual GalNAc-transferases have distinct activities and initiation of
''O''-glycosylation is regulated by a repertoire of GalNAc-transferases. The protein encoded by this gene is highly
homologous to other family members; however, the enzymes have different substrate specificities.
References
Further reading
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