beta-1,3-glucuronyltransferase 3 (glucuronosyltransferase-1, galactosylgalactosylxylosylprotein 3-beta-glucuronosyltransferase 3, GlcAT-1, UDP-GlcUA:Gal beta-1,3-Gal-R glucuronyltransferase, GlcUAT-I, B3GAT3)

Function

• glycosaminoglycans biosynthesis
• role in forminglinkage tetrasaccharide present in heparan sulfate & chondroitin sulfate
• transfers a glucuronic acid moiety from the uridine diphosphate-glucuronic acid (UDP-GlcUA) to the common linkage region trisaccharide gal-beta-1,3-gal-beta-1,4-Xyl covalently bound to Ser at the glycosaminylglycan attachment site of proteoglycans
• role in biosynthesis of l2/HNK-1 carbohydrate epitope on glycoproteins
• specificity for gal-beta-1,3-gal-beta-1,4-Xyl, negligible incorporation into other galactoside substrates
• inhibited by EDTA
• protein modification; protein glycosylation

Cofactor: Mn+2

Structure

• homodimer, disulfide-linked
• N-glycosylated
• belongs to the glycosyltransferase 43 family

Compartment

Golgi

Expression

• ubiquitous (but weakly expressed in all tissues examined)

More general terms

• UDP-glucuronosyltransferase (UDPGT)

Database

• UniProt: http://www.uniprot.org/uniprot/O94766.html
• OMIM: https://mirror.omim.org/entry/606374