Polypeptide N-acetylgalactosaminyltransferase 3 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 ''GALNT3''
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 ...
.
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 g ...
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 − form un ...
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 under biological conditions), a carboxyl group (which is in the deprotonated −COOâ ...
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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