UDP GlcUA:Gal beta 1,3 Gal R glucuronyltransferase
UDP GlcUA:Gal beta 1,3 GalR glucuronyltransferase
Glycosaminoglycans biosynthesis. Involved in forming the linkage tetrasaccharide present in heparan sulfate and 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 a Ser residue at the glycosaminylglycan attachment site of proteoglycans. Can also play a role in the biosynthesis of l2/HNK-1 carbohydrate epitope on glycoproteins. Shows strict specificity for Gal-beta-1,3-Gal-beta-1,4-Xyl, exhibiting negligible incorporation into other galactoside substrates including Galbeta1-3Gal beta1-O-benzyl, Galbeta1-4GlcNAc and Galbeta1-4Glc.
Ubiquitous (but weakly expressed in all tissues examined).
Protein modification; protein glycosylation.
Involvement in disease
Defects in B3GAT3 are the cause of multiple joint dislocations short stature craniofacial dysmorphism and congenital heart defects (JDSSDHD) [MIM:245600]. An autosomal recessive disease characterized by dysmorphic facies, bilateral dislocations of the elbows, hips, and knees, clubfeet, and short stature, as well as cardiovascular defects.