Reaction: (1) UDP-α-D-glucuronate + [protein]-3-O-(β-D-GalNAc-(1→4)-β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine = UDP + [protein]-3-O-(β-D-GlcA-(1→3)-β-D-GalNAc-(1→4)-β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine
(2) UDP-α-D-glucuronate + [protein]-3-O-([β-D-GalNAc-(1→4)-β-D-GlcA-(1→3)]n-β-D-GalNAc-(1→4)-β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine = UDP + [protein]-3-O-(β-D-GlcA-(1→3)-[β-D-GalNAc-(1→4)-β-D-GlcA-(1→3)]n-β-D-GalNAc-(1→4)-β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine
For diagram of reaction click here.
Other name(s): chondroitin glucuronyltransferase II; α-D-glucuronate:N-acetyl-β-D-galactosaminyl-(1→4)-β-D-glucuronosyl-proteoglycan 3-β-glucuronosyltransferase; UDP-α-D-glucuronate:N-acetyl-β-D-galactosaminyl-(1→4)-β-D-glucuronosyl-proteoglycan 3-β-glucuronosyltransferase
Systematic name: UDP-α-D-glucuronate:[protein]-3-O-(β-D-GalNAc-(1→4)-β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine = UDP + [protein]-3-O-(β-D-GlcA-(1→3)-β-D-GalNAc-(1→4)-β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine 3-β-glucuronosyltransferase (configuration-inverting)
Comments: Involved in the biosynthesis of chondroitin and dermatan sulfate. The human chondroitin synthetase is a bifunctional glycosyltransferase, which has the 3-β-glucuronosyltransferase and 4-β-N-acetylgalactosaminyltransferase (EC 2.4.1.175) activities required for the synthesis of the chondroitin sulfate disaccharide repeats. Similar chondroitin synthase ’co-polymerases’ can be found in Pasteurella multocida and Escherichia coli. There is also another human protein with apparently only the 3-β-glucuronosyltransferase activity.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 269077-98-7
References:
1. Kitagawa, H., Uyama, T. and Sugahara, K. Molecular cloning and expression of a human chondroitin synthase. J. Biol. Chem. 276 (2001) 38721-38726. [PMID: 11514575]
2. DeAngelis, P.L. and Padgett-McCue, A.J. Identification and molecular cloning of a chondroitin synthase from Pasteurella multocida type F. J. Biol. Chem. 275 (2000) 24124-24129. [PMID: 10818104]
3. Ninomiya, T., Sugiura, N., Tawada, A., Sugimoto, K., Watanabe, H. and Kimata, K. Molecular cloning and characterization of chondroitin polymerase from Escherichia coli strain K4. J. Biol. Chem. 277 (2002) 21567-21575. [PMID: 11943778]
4. Gotoh, M., Yada, T., Sato, T., Akashima, T., Iwasaki, H., Mochizuki, H., Inaba, N., Togayachi, A., Kudo, T., Watanabe, H., Kimata, K. and Narimatsu, H. Molecular cloning and characterization of a novel chondroitin sulfate glucuronyltransferase which transfers glucuronic acid to N-acetylgalactosamine. J. Biol. Chem. 277 (2002) 38179-38188. [PMID: 12145278]