Reaction: UDP-α-D-glucuronate + N-acetyl-α-D-glucosaminyl-(1→4)-β-D-glucuronosyl-proteoglycan = UDP + β-D-glucuronosyl-(1→4)-N-acetyl-α-D-glucosaminyl-(1→4)-β-D-glucuronosyl-proteoglycan
For diagram click here.
Other name(s): N-acetylglucosaminylproteoglycan β-1,4-glucuronyltransferase; heparan glucuronyltransferase II
Systematic name: UDP-α-D-glucuronate:N-acetyl-α-D-glucosaminyl-(1→4)-β-D-glucuronosyl-proteoglycan 4-β-glucuronosyltransferase
Comments: Involved in the biosynthesis of heparin and heparan sulfate. Some forms of the human enzyme (particularly the enzyme complex encoded by the EXT1 and EXT2 genes) act as bifunctional glycosyltransferases, which also have the glucuronosyl-N-acetylglucosaminyl-proteoglycan 4-α-N-acetylglucosaminyltransferase (EC 22.214.171.124, glucuronosyl-N-acetylglucosaminyl-proteoglycan 4-α-N-acetylglucosaminyltransferase) activity required for the synthesis of the heparan sulfate disaccharide repeats.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 145539-84-0
1. Senay, C., Lind, T., Muguruma, K., Tone, Y., Kitagawa, H., Sugahara, K., Lidholt, K., Lindahl, U. and Kusche-Gullberg, M. The EXT1/EXT2 tumor suppressors: catalytic activities and role in heparan sulfate biosynthesis. EMBO Rep. 1 (2000) 282-286. [PMID: 11256613]
2. Lind, T., Tufaro, F., McCormick, C., Lindahl, U. and Lidholt, K. The putative tumor suppressors EXT1 and EXT2 are glycosyltransferases required for the biosynthesis of heparan sulfate. J. Biol. Chem. 273 (1998) 26265-26268. [PMID: 9756849]