IUBMB Enzyme Nomenclature


Accepted name: D-Man-α-(1→3)-D-Glc-β-(1→4)-D-Glc-α-1-diphosphoundecaprenol 2-β-glucuronosyltransferase

Reaction: UDP-α-D-glucuronate + α-D-Man-(1→3)-β-D-Glc-(1→4)-α-D-Glc-1-diphospho-ditrans,octacis-undecaprenol = UDP + β-D-GlcA-(1→2)-α-D-Man-(1→3)-β-D-Glc-(1→4)-α-D-Glc-1-diphospho-ditrans,octacis-undecaprenol

For diagram of reaction click here

Other name(s): GumK; UDP-glucuronate:D-Man-α-(1→3)-D-Glc-β-(1→4)-D-Glc-α-1-diphospho-ditrans,octacis-undecaprenol β-1,2-glucuronyltransferase; D-Man-α-(1→3)-D-Glc-β-(1→4)-D-Glc-α-1-diphosphoundecaprenol 2-β-glucuronyltransferase

Systematic name: UDP-α-D-glucuronate:α-D-Man-(1→3)-β-D-Glc-(1→4)-α-D-Glc-1-diphospho-ditrans,octacis-undecaprenol β-1,2-glucuronosyltransferase (configuration-inverting)

Comments: The enzyme is involved in the biosynthesis of the exopolysaccharides xanthan (in the bacterium Xanthomonas campestris) and acetan (in the bacterium Gluconacetobacter xylinus).

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:


1. Katzen, F., Ferreiro, D.U., Oddo, C.G., Ielmini, M.V., Becker, A., Puhler, A. and Ielpi, L. Xanthomonas campestris pv. campestris gum mutants: effects on xanthan biosynthesis and plant virulence. J. Bacteriol. 180 (1998) 1607-1617. [PMID: 9537354]

2. Ielpi, L., Couso, R.O. and Dankert, M.A. Sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in Xanthomonas campestris. J. Bacteriol. 175 (1993) 2490-2500. [PMID: 7683019]

3. Kim, S.Y., Kim, J.G., Lee, B.M. and Cho, J.Y. Mutational analysis of the gum gene cluster required for xanthan biosynthesis in Xanthomonas oryzae pv oryzae. Biotechnol. Lett. 31 (2009) 265-270. [PMID: 18854951]

4. Barreras, M., Bianchet, M.A. and Ielpi, L. Crystallization and preliminary crystallographic characterization of GumK, a membrane-associated glucuronosyltransferase from Xanthomonas campestris required for xanthan polysaccharide synthesis. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 62 (2006) 880-883. [PMID: 16946469]

5. Barreras, M., Salinas, S.R., Abdian, P.L., Kampel, M.A. and Ielpi, L. Structure and mechanism of GumK, a membrane-associated glucuronosyltransferase. J. Biol. Chem. 283 (2008) 25027-25035. [PMID: 18596046]

6. Vojnov, A.A., Bassi, D.E., Daniels, M.J. and Dankert, M.A. Biosynthesis of a substituted cellulose from a mutant strain of Xanthomonas campestris. Carbohydr. Res. 337 (2002) 315-326. [PMID: 11841812]

7. Barreras, M., Abdian, P.L. and Ielpi, L. Functional characterization of GumK, a membrane-associated β-glucuronosyltransferase from Xanthomonas campestris required for xanthan polysaccharide synthesis. Glycobiology 14 (2004) 233-241. [PMID: 14736729]

[EC created 2011, modified 2016]

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