D-Man-alpha-(1-3)-D-Glc-beta-(1-4)-D-Glc-alpha-1-diphosphoundecaprenol 2-beta-glucuronyltransferase explained

D-Man-alpha-(1->3)-D-Glc-beta-(1->4)-D-Glc-alpha-1-diphosphoundecaprenol 2-beta-glucuronyltransferase
Ec Number:	2.4.1.264

D-Man-alpha-(1->3) -D-Glc-beta-(1->4) -D-Glc-alpha-1-diphosphoundecaprenol 2-beta-glucuronyltransferase (GumK) is an enzyme with the systematic name UDP-glucuronate: D-Man-alpha-(1->3) -D-Glc-beta-(1->4)-D-Glc-alpha-1-diphospho-ditrans,octacis-undecaprenol beta-1,2-glucuronyltransferase.^{[1] [2] [3] [4] [5] [6] [7]} This enzyme catalyses the following chemical reaction:

UDP-glucuronate + D-Man-alpha-(1->3) -D-Glc-beta-(1->4) -D-Glc-alpha-1-diphospho-ditrans,octacis-undecaprenol

\rightleftharpoons UDP + D-GlcA-beta-(1->2) -D-Man-alpha-(1->3) -D-Glc-beta-(1->4) -D-Glc-alpha-1-diphospho-ditrans,octacis-undecaprenol

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

Notes and References

1. Katzen F, Ferreiro DU, Oddo CG, Ielmini MV, Becker A, Pühler A, Ielpi L . Xanthomonas campestris pv. campestris gum mutants: effects on xanthan biosynthesis and plant virulence . Journal of Bacteriology . 180 . 7 . 1607–17 . April 1998 . 10.1128/JB.180.7.1607-1617.1998 . 9537354 . 107069 .
2. Ielpi L, Couso RO, Dankert MA . Sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in Xanthomonas campestris . Journal of Bacteriology . 175 . 9 . 2490–500 . May 1993 . 10.1128/jb.175.9.2490-2500.1993 . 7683019 . 204549 .
3. Kim SY, Kim JG, Lee BM, Cho JY . Mutational analysis of the gum gene cluster required for xanthan biosynthesis in Xanthomonas oryzae pv oryzae . Biotechnology Letters . 31 . 2 . 265–70 . February 2009 . 18854951 . 10.1007/s10529-008-9858-3 .
4. Barreras M, Bianchet MA, Ielpi L . Crystallization and preliminary crystallographic characterization of GumK, a membrane-associated glucuronosyltransferase from Xanthomonas campestris required for xanthan polysaccharide synthesis . Acta Crystallographica. Section F, Structural Biology and Crystallization Communications . 62 . Pt 9 . 880–3 . September 2006 . 16946469 . 2242869 . 10.1107/S1744309106028764 .
5. Barreras M, Salinas SR, Abdian PL, Kampel MA, Ielpi L . Structure and mechanism of GumK, a membrane-associated glucuronosyltransferase . The Journal of Biological Chemistry . 283 . 36 . 25027–35 . September 2008 . 18596046 . 3259810 . 10.1074/jbc.M801227200 . free .
6. Vojnov AA, Bassi DE, Daniels MJ, Dankert MA . Biosynthesis of a substituted cellulose from a mutant strain of Xanthomonas campestris . Carbohydrate Research . 337 . 4 . 315–26 . February 2002 . 11841812 . 10.1016/S0008-6215(01)00322-6 .
7. Barreras M, Abdian PL, Ielpi L . Functional characterization of GumK, a membrane-associated beta-glucuronosyltransferase from Xanthomonas campestris required for xanthan polysaccharide synthesis . Glycobiology . 14 . 3 . 233–41 . March 2004 . 14736729 . 10.1093/glycob/cwh056 . free .