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
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).
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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