+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Identification, genetic and biochemical analysis of genes involved in synthesis of sugar nucleotide precursors of xanthan gum

, : Identification, genetic and biochemical analysis of genes involved in synthesis of sugar nucleotide precursors of xanthan gum. Journal of General Microbiology 139(3): 447-457

A genetic and biochemical analysis of Xanthomonas campestris chromosomal functions required for xanthan polysaccharide synthesis (xps) was undertaken. Seven xps DNA regions were isolated after conjugation of chemically induced non-mucoid mutants with a genomic library of X. campestris DNA. No overlapping segments between regions were detected, based on physical mapping, indicating the unlinked character of these regions. Clones complementing several different mutants belonging to the same region contained overlapping segments of X. campestris chromosomal DNA. Complementation and biochemical analysis, and DNA mapping were used to identify and characterize xpsZZZ, ZV and VZ DNA regions. Mutants in these three regions were able to synthesize both lipid intermediates and xanthan gum in vitro when sugar nucleotides were provided as substrates. HPLC analysis of the intracellular sugar nucleotide content showed that the XpsIII group comprises two different classes of mutants : XpsIIIA, defective in UDP-glucose, UDP-glucuronic acid and GDP-mannose, and XpsIIIB,defective in GDP-mannose. XpsIV mutants were defective in UDP-glucose and UDP-glucuronic acid, and XpsVI mutants were defective only in UDP-glucuronic acid. Analysis of enzyme activities involved in the synthesis of UDP-glucose, GDP-mannose and UDP-glucuronic acid indicated that the xpsZZZA region affects the activity of the phosphoglucomutase/phosphomannomutase enzyme, and the xpsZZZB region affects the mannoisomerase/phosphomannoisomerase activities. The xpsZV mutations affect the activity of the UDPG-pyrophosphorylase enzyme, and the xps VZ mutations affect the activity of the UDPG-dehydrogenase enzyme.


PMID: 20050414

DOI: 10.1099/00221287-139-3-447

Other references

Poulton, D.R., 1996: The future of the specialty of orthodontics. Journal of the California Dental Association 24(11): 25-27

Taylor, E.W.; Jaakkola, J., 1991: A transposition of the reverse transcriptase gene reveals unexpected structural homology to E. coli DNA polymerase I. The rational design of antiviral agents targeting the reverse transcriptase (RT) of the human immunodeficiency virus (HIV) would greatly benefit from a more intimate knowledge of the structure of RT. Until now, the degree of sequence similarity be...

Grzybowski, Joseph A., 1993: The spring season. March 1 - May 28, 1993. Southern Great Plains Region. American BirdsFall; 47(3): 426-429

Hugues, F.C.; Munera, Y.; L.J.unne, C., 1985: Unusual indications for beta-blockers. Therapie 40(6): 417-421

Gwinner, K.P.; Prince, J.Bruce.; Andrus, D.M., 2006: Attracting students into careers in food supply veterinary medicine. This article reports on the broad issues and factors that influences a veterinary student's selection of a career path in Food Supply Veterinary Medicine (FSVM) and strategies that will be most effective for attracting students to careers in...

Tadzhibekov M., 1987: Modern gravity sliding on the Dzhur'yaz Plateau, Hissar Range. Doklady Akademii Nauk Tadzhikskoy SSR 1987(6): 372-375

Albert, R.; Zervos, C., 1990: Application of multivariate techniques to the solution of problems of food regulation: orange juice adulteration. Developments in food science: 4) 595-610

Lavielle J.; Amalric R.; Stanoyevitch J.F.; Hopf M.A.; Antipoff G.M.; Roux H., 1986: Contribution of magnetic resonance imaging in rheumatology. The authors report their experience with magnetic resonance imaging in rheumatology, established on more than 250 examinations. The method seems interesting for the study of discal and somatic spine diseases, and especially for the evaluation of t...

Yeoman L.J.; Shaw D., 1989: Computerized tomography appearances of pelvic hemangioma involving the large bowel in childhood. The Computed Tomography (CT) appearance of a pelvic haemangioma involving the rectum in two children, one with the Vater association and one with Klippel-Trenaunay syndrome, is described. Both cases complained of painless rectal bleeding and the d...

Templeton J.F.; Jackson C J.C., 1983: Metabolism of 17 alpha methyltestosterone in the rabbit 6 carbon and 16 carbon hydroxylated metabolites. 17.alpha.-Methyltestosterone and the reduced metabolites, 17.alpha.-methyl-5.alpha.-androstane-3.alpha.,17.beta.-diol, 17.alpha.-methyl-5.alpha.-androstane-3.beta.,17.beta.-diol and 17.alpha.-methyl-5.beta.-androstane-3.alpha.,17.beta.-diol, toget...