Glycosyltransferase
Glycosyltransferases (GTFs, Gtfs) are enzymes (EC 2.4) that establish natural glycosidic linkages. They catalyze the transfer of saccharide moieties from an activated nucleotide sugar (also known as the "glycosyl donor") to a nucleophilic glycosyl acceptor molecule, the nucleophile of which can be oxygen- carbon-, nitrogen-, or sulfur-based.

The result of glycosyl transfer can be a carbohydrate, glycoside, oligosaccharide, or a polysaccharide. Some glycosyltransferases catalyse transfer to inorganic phosphate or water. Glycosyl transfer can also occur to protein residues, usually to tyrosine, serine, or threonine to give O-linked glycoproteins, or to asparagine to give N-linked glycoproteins. Mannosyl groups may be transferred to tryptophan to generate C-mannosyl tryptophan, which is relatively abundant in eukaryotes. Transferases may also use lipids as an acceptor, forming glycolipids, and even use lipid-linked sugar phosphate donors, such as dolichol phosphates in eukaryotic organism, or undecaprenyl phosphate in bacteria.

Glycosyltransferases that use sugar nucleotide donors are Leloir enzymes, after Luis F. Leloir, the scientist who discovered the first sugar nucleotide and who received the 1970 Nobel Prize in Chemistry for his work on carbohydrate metabolism. Glycosyltransferases that use non-nucleotide donors such as dolichol or polyprenol pyrophosphate are non-Leloir glycosyltransferases.

Mammals use only 9 sugar nucleotide donors for glycosyltransferases: UDP-glucose, UDP-galactose, UDP-GlcNAc, UDP-GalNAc, UDP-xylose, UDP-glucuronic acid, GDP-mannose, GDP-fucose, and CMP-sialic acid. The phosphate(s) of these donor molecules are usually coordinated by divalent cations such as manganese, however metal independent enzymes exist.

Many glycosyltransferases are single-pass transmembrane proteins, and they are usually anchored to membranes of Golgi apparatus
Q8047
enzyme
Concept
Q741108
EC 2.4
UNK
Q82264
catalyze
Concept
Q11358
saccharide
Concept
Q23005640
moieties
Concept
Q117973
nucleotide sugar
UNK
Q17054443
glycosyl donor
UNK
Q745930
nucleophilic
UNK
Q16258933
glycosyl acceptor
UNK
Q629
oxygen
Concept
Q623
carbon
Concept
Q627
nitrogen
Concept
Q682
sulfur
Concept
Q173600
carbohydrate
Concept
Q192639
glycoside
Concept
Q320607
oligosaccharide
Concept
Q134219
polysaccharide
Concept
Q46220103
inorganic phosphate
Concept
Q283
water
Concept
Q8054
protein
Concept
Q188017
tyrosine
Concept
Q183290
serine
Concept
Q186521
threonine
Concept
Q187126
glycoprotein
Concept
Q185906
asparagine
Concept
Q181003
tryptophan
Concept
None
C-mannosyl tryptophan
UNK
Q11367
lipids
Concept
Q422882
glycolipids
Concept
Q418203
dolichol
UNK
Q409695
undecaprenyl phosphate
UNK
Q233985
Luis F. Leloir
PER
Q44585
Nobel Prize in Chemistry
EVE
Q418203
dolichol
UNK
Q7226864
polyprenol
UNK
Q55506489
pyrophosphate
Concept
Q424649
UDP-glucose
Concept
Q259015
UDP-galactose
UNK
Q312208
UDP-GlcNAc
UNK
None
UDP-GalNAc
UNK
None
UDP-xylose
UNK
Q277638
UDP-glucuronic acid
UNK
Q217404
GDP-mannose
UNK
None
GDP-fucose
UNK
None
CMP-sialic acid
UNK
Q55642912
single-pass transmembrane protein
Concept
Q83181
Golgi apparatus
Concept
Q67201373
Glycosyltransferase
Concept
Q67201373
Glycosyltransferase
Concept
Q67201373
Glycosyltransferase
Concept
1970-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1970
DATE
+2.4^^http://www.w3.org/2001/XMLSchema#decimal
2.4
NUMBER
+9^^http://www.w3.org/2001/XMLSchema#decimal
9
NUMBER
award received