Identification, genetic and biochemical analysis of genes involved in synthesis of sugar nucleotide precursors of xanthan gum
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 overla...
| Autor principal: | |
|---|---|
| Publicado: |
1993
|
| Materias: | |
| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00221287_v139_n3_p447_Harding http://hdl.handle.net/20.500.12110/paper_00221287_v139_n3_p447_Harding |
| Aporte de: |
| id |
paper:paper_00221287_v139_n3_p447_Harding |
|---|---|
| record_format |
dspace |
| spelling |
paper:paper_00221287_v139_n3_p447_Harding2023-06-08T14:46:30Z Identification, genetic and biochemical analysis of genes involved in synthesis of sugar nucleotide precursors of xanthan gum Ielpi, Luis phosphoglucomutase phosphomannomutase sugar nucleotide unclassified drug uridine diphosphate glucose dehydrogenase uridine triphosphate glucose 1 phosphate uridylyltransferase xanthan article bacterium mutant biosynthesis carbohydrate metabolism high performance liquid chromatography molecular cloning priority journal Xanthomonas Bacteria (microorganisms) Xanthomonas campestris 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 xpsIII, IV and VI 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 XpsIff 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 xpsIIIA region affects the activity of the phosphoglucomutase/phosphomannomutase enzyme, and the xpsIIIB region affects the mannoisomerase/phosphomannoisomerase activities. The xpsIV mutations affect the activity of the UDPG-pyrophosphorylase enzyme, and the xps VI mutations affect the activity of the UDPG-dehydrogenase enzyme. Fil:Ielpi, L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1993 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00221287_v139_n3_p447_Harding http://hdl.handle.net/20.500.12110/paper_00221287_v139_n3_p447_Harding |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
phosphoglucomutase phosphomannomutase sugar nucleotide unclassified drug uridine diphosphate glucose dehydrogenase uridine triphosphate glucose 1 phosphate uridylyltransferase xanthan article bacterium mutant biosynthesis carbohydrate metabolism high performance liquid chromatography molecular cloning priority journal Xanthomonas Bacteria (microorganisms) Xanthomonas campestris |
| spellingShingle |
phosphoglucomutase phosphomannomutase sugar nucleotide unclassified drug uridine diphosphate glucose dehydrogenase uridine triphosphate glucose 1 phosphate uridylyltransferase xanthan article bacterium mutant biosynthesis carbohydrate metabolism high performance liquid chromatography molecular cloning priority journal Xanthomonas Bacteria (microorganisms) Xanthomonas campestris Ielpi, Luis Identification, genetic and biochemical analysis of genes involved in synthesis of sugar nucleotide precursors of xanthan gum |
| topic_facet |
phosphoglucomutase phosphomannomutase sugar nucleotide unclassified drug uridine diphosphate glucose dehydrogenase uridine triphosphate glucose 1 phosphate uridylyltransferase xanthan article bacterium mutant biosynthesis carbohydrate metabolism high performance liquid chromatography molecular cloning priority journal Xanthomonas Bacteria (microorganisms) Xanthomonas campestris |
| description |
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 xpsIII, IV and VI 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 XpsIff 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 xpsIIIA region affects the activity of the phosphoglucomutase/phosphomannomutase enzyme, and the xpsIIIB region affects the mannoisomerase/phosphomannoisomerase activities. The xpsIV mutations affect the activity of the UDPG-pyrophosphorylase enzyme, and the xps VI mutations affect the activity of the UDPG-dehydrogenase enzyme. |
| author |
Ielpi, Luis |
| author_facet |
Ielpi, Luis |
| author_sort |
Ielpi, Luis |
| title |
Identification, genetic and biochemical analysis of genes involved in synthesis of sugar nucleotide precursors of xanthan gum |
| title_short |
Identification, genetic and biochemical analysis of genes involved in synthesis of sugar nucleotide precursors of xanthan gum |
| title_full |
Identification, genetic and biochemical analysis of genes involved in synthesis of sugar nucleotide precursors of xanthan gum |
| title_fullStr |
Identification, genetic and biochemical analysis of genes involved in synthesis of sugar nucleotide precursors of xanthan gum |
| title_full_unstemmed |
Identification, genetic and biochemical analysis of genes involved in synthesis of sugar nucleotide precursors of xanthan gum |
| title_sort |
identification, genetic and biochemical analysis of genes involved in synthesis of sugar nucleotide precursors of xanthan gum |
| publishDate |
1993 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00221287_v139_n3_p447_Harding http://hdl.handle.net/20.500.12110/paper_00221287_v139_n3_p447_Harding |
| work_keys_str_mv |
AT ielpiluis identificationgeneticandbiochemicalanalysisofgenesinvolvedinsynthesisofsugarnucleotideprecursorsofxanthangum |
| _version_ |
1768542443742953472 |