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...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Harding, N.E., Raffo, S., Raimondi, A., Cleary, J.M., Ielpi, L.
Formato: JOUR
Materias:
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00221287_v139_n3_p447_Harding
Aporte de:
id todo:paper_00221287_v139_n3_p447_Harding
record_format dspace
spelling todo:paper_00221287_v139_n3_p447_Harding2023-10-03T14:27:21Z Identification, genetic and biochemical analysis of genes involved in synthesis of sugar nucleotide precursors of xanthan gum Harding, N.E. Raffo, S. Raimondi, A. Cleary, J.M. Ielpi, L. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar 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
Harding, N.E.
Raffo, S.
Raimondi, A.
Cleary, J.M.
Ielpi, L.
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.
format JOUR
author Harding, N.E.
Raffo, S.
Raimondi, A.
Cleary, J.M.
Ielpi, L.
author_facet Harding, N.E.
Raffo, S.
Raimondi, A.
Cleary, J.M.
Ielpi, L.
author_sort Harding, N.E.
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
url http://hdl.handle.net/20.500.12110/paper_00221287_v139_n3_p447_Harding
work_keys_str_mv AT hardingne identificationgeneticandbiochemicalanalysisofgenesinvolvedinsynthesisofsugarnucleotideprecursorsofxanthangum
AT raffos identificationgeneticandbiochemicalanalysisofgenesinvolvedinsynthesisofsugarnucleotideprecursorsofxanthangum
AT raimondia identificationgeneticandbiochemicalanalysisofgenesinvolvedinsynthesisofsugarnucleotideprecursorsofxanthangum
AT clearyjm identificationgeneticandbiochemicalanalysisofgenesinvolvedinsynthesisofsugarnucleotideprecursorsofxanthangum
AT ielpil identificationgeneticandbiochemicalanalysisofgenesinvolvedinsynthesisofsugarnucleotideprecursorsofxanthangum
_version_ 1807314765920337920