Search
xylosyltransferase 1 (XylT-1, peptide O-xylosyltransferase 1, XYLT1, XT1)
Function:
1) catalyzes 1st step in biosynthesis of glycosaminoglycan
2) transfers D-xylose from UDP-D-xylose to Ser of nascent glycoprotein
3) initial enzyme in biosynthesis of chondroitin sulfate & dermatan sulfate proteoglycans in fibroblasts & chondrocytes
4) transfers a beta-D-xylosyl residue from UDP-D-xylose to Ser hydroxy group of an acceptor glycoprotein
Cofactor: divalent cations
Kinetic parameters:
- KM=0.9 uM for recombinant bikunin
- Vmax=764 pmol/h/mg enzyme with recombinant bikunin as substrate
Structure:
- monomer, contains 7 disulfide bonds, N-glycosylated
- belongs to the glycosyltransferase 14 family, XylT subfamily
Compartment:
- endoplasmic reticulum, Golgi, extracellular together with chondroitin sulfate proteoglycans
Expression:
- widely expressed
- expressed in placenta, kidney, pancreas > skeletal muscle
Pathology:
- activity is diminished in seminal plasma of unfertile men
General
glycoprotein
glycosyltransferase
Properties
SIZE: MW = 108 kD
entity length = 959 aa
COMPARTMENT: golgi
endoplasmic reticulum
MOTIF: transmembrane domain {18-38}
N-glycosylation site {N226}
N-glycosylation site {N421}
N-glycosylation site {N777}
Database Correlations
OMIM 608124
MORBIDMAP 608124
UniProt Q86Y38
Pfam PF02485
ENZYME 2.4.2.26
References
- UniProt :accession Q86Y38
- GGDB; NOTE=GlycoGene database
http://ggdb.muse.aist.go.jp/GGDB/index.jsp