Nucleotide Sequence and Expression of UDP-Glucose Dehydrogenase Gene Required for the Synthesis of Xanthan Gum in Xanthomonas-campestris

Lin, Cheng-Sheng; Lin, Ning; Yang, Bing; Weng, Shu-Fen; Tseng, Yi-Hsiung

doi:10.1006/bbrc.1995.1176

Cited by 23 publications

(4 citation statements)

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“…24-kb insert which contained the rfbCDAB gene cluster required for lipopolysaccharide synthesis and the pmi gene involved in xanthan synthesis (26,(51)(52)(53). The eps3 mutants (BG44E and AG60E) were complemented by pSD701 carrying the UDP-glucose dehydrogenase gene (33). The eps6 mutant (G76E) was complemented by clone pEK6 carrying the gene encoding UDP-glucose pyrophosphorylase (58,59).…”

Section: Resultsmentioning

confidence: 99%

Chromosome Map of Xanthomonas campestris pv. campestris 17 with Locations of Genes Involved in Xanthan Gum Synthesis and Yellow Pigmentation

et al. 1999

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No plasmid was detected in Xanthomonas campestris pv. campestris 17, a strain of the causative agent of black rot in cruciferous plants isolated in Taiwan. Its chromosome was cut byPacI, PmeI, and SwaI into five, two, and six fragments, respectively, and a size of 4.8 Mb was estimated by summing the fragment lengths in these digests. Based on the data obtained from partial digestion and Southern hybridization using probes common to pairs of the overlapping fragments or prepared from linking fragments, a circular physical map bearing thePacI, PmeI, and SwaI sites was constructed for the X. campestris pv. campestris 17 chromosome. Locations of eight eps loci involved in exopolysaccharide (xanthan gum) synthesis, two rrn operons each possessing an unique I-CeuI site, one pigcluster required for yellow pigmentation, and nine auxotrophic markers were determined, using mutants isolated by mutagenesis with Tn5(pfm)CmKm. This transposon contains a polylinker with sites for several rare-cutting restriction endonucleases located between the chloramphenicol resistance and kanamycin resistance (Kmr) genes, which upon insertion introduced additional sites into the chromosome. The recA and tdhgenes, with known sequences, were mapped by tagging with the polylinker-Kmr segment from Tn5(pfm)CmKm. This is the first map for X. campestris and would be useful for genetic studies of this and related Xanthomonas species.

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Section: Resultsmentioning

confidence: 99%

Chromosome Map of Xanthomonas campestris pv. campestris 17 with Locations of Genes Involved in Xanthan Gum Synthesis and Yellow Pigmentation

et al. 1999

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“…The assay mixture contained 100 mM Tris-HCl buffer (pH 8.5), 1 mM MgCl 2 , 5 mM dithiothreitol, 2 mM NAD, 1 mM UDP-glucose, and 200 to 400 mg of the soluble protein fractions in a 1-ml volume. One unit of UDP-glucose dehydrogenase is defined as the amount of enzyme that catalyzes the reduction of 1 micromole of NAD per minute (18).…”

Section: Methodsmentioning

confidence: 99%

Novel rkp Gene Clusters of Sinorhizobium meliloti Involved in Capsular Polysaccharide Production and Invasion of the Symbiotic Nodule: the rkpK Gene Encodes a UDP-Glucose Dehydrogenase

et al. 1998

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The production of exopolysaccharide (EPS) was shown to be required for the infection process by rhizobia that induce the formation of indeterminate nodules on the roots of leguminous host plants. InSinorhizobium meliloti (also known as Rhizobium meliloti) Rm41, a capsular polysaccharide (KPS) analogous to the group II K antigens of Escherichia coli can replace EPS during symbiotic nodule development and serve as an attachment site for the strain-specific bacteriophage φ16-3. The rkpA to -J genes in the chromosomal rkp-1 region code for proteins that are involved in the synthesis, modification, and transfer of an as-yet-unknown lipophilic molecule which might function as a specific lipid carrier during KPS biosynthesis. Here we report that with a phage φ16-3-resistant population obtained after random Tn5 mutagenesis, we have identified novel mutants impaired in KPS production by genetic complementation and biochemical studies. The mutations represent two novel loci, designated therkp-2 and rkp-3 regions, which are required for the synthesis of rhizobial KPS. The rkp-2 region harbors two open reading frames (ORFs) organized in monocistronic transcription units. Although both genes are required for normal lipopolysaccharide production, only the second one, designated rkpK, is involved in the synthesis of KPS. We have demonstrated that RkpK possesses UDP-glucose dehydrogenase activity, while the protein product of ORF1 might function as a UDP-glucuronic acid epimerase.

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“…The compounds are as follows: 1, D-glucose-6-phosphate; 2, D-glucose-1-phosphate; 3, UDP-D-glucose; 4, UDP-D-glucuronic acid; 5, fructose-6-phosphate; 6, mannose-6-phosphate; 7, mannose-1-phosphate; 8, GDP-D-mannose; 9, GDP-4-keto-6-deoxy-D-mannose; 10, GDP-D-rhamnose; 11, dTDP-D-glucose; 12, dTDP-4-keto-6-deoxy-D-glucose, also known as dTDP-6-deoxy-Dxylo-4-hexulose; 13, dTDP-4-keto-6-deoxy-L-mannose, also known as dTDP-6-deoxy-L-lyxo-4-hexulose; 14, dTDP-L-rhamnose; 15, dTDP-3-keto-6-deoxy-D-galactose; 16, dTDP-3-amino-3,6-dideoxy-D-galactose; 17, dTDP-N-acetyl-3-amino-3,6-dideoxy-Dgalactose. Recently, the genes encoding the enzymes UDP-glucose pyrophosphorylase (compound 2®compound 3) and UDP-glucose dehydrogenase (compound 3®compound 4) were identi®ed at distinct genomic locations (Lin et al 1995;Wei et al 1996). Ac, acetyl residue; P, phosphate residue (Table 3).…”

Section: Genes In Wxc Region 1 Are Necessary For Biosynthesis Of Lps mentioning

confidence: 99%

Lipopolysaccharide biosynthesis in Xanthomonas campestris pv. campestris: a cluster of 15 genes is involved in the biosynthesis of the LPS O-antigen and the LPS core

2001

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As a result of mutational and DNA sequence analysis, a wxc gene cluster involved in the synthesis of the surface lipopolysaccharide (LPS) was identified in Xanthomonas campestris pv. campestris. This gene cluster comprises 15 genes. It was located on a cloned 35-kb fragment of chromosomal DNA, close, but not directly adjacent, to previously characterized genes for LPS biosynthesis. The G + C content of all but one of the wxc genes was atypically low for X. campestris pv. campestris, while the G + C distribution was uniform throughout the cluster. An SDS-PAGE analysis of mutant strains defective in various wxc genes confirmed that genes from this cluster were involved in LPS biosynthesis. The mutant phenotypes allowed the differentiation of three regions within the wxc cluster. Genes from wxc region 1 are necessary for the biosynthesis of the water-soluble LPS O-antigen. Analysis of DNA and deduced amino acid sequences led to the identification of two glycosyltransferases, two components of an ABC transport system, and a possible kinase among the seven putative proteins encoded by genes constituting wxc region 1. The two genes in wxc region 2 were similar to gmd and rmd, which direct the synthesis of the sugar nucleotide GDP-D-rhamnose. Mutations affecting wxc region 2 demonstrated its involvement in the formation of the LPS core. Genes from wxc region 3 showed similarities to genes that code for enzymes that modify nucleotide sugars, and to components of sugar translocation systems that have so far been rarely described in bacteria.

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Nucleotide Sequence and Expression of UDP-Glucose Dehydrogenase Gene Required for the Synthesis of Xanthan Gum in Xanthomonas-campestris

Cited by 23 publications

References 0 publications

Chromosome Map of Xanthomonas campestris pv. campestris 17 with Locations of Genes Involved in Xanthan Gum Synthesis and Yellow Pigmentation

Chromosome Map of Xanthomonas campestris pv. campestris 17 with Locations of Genes Involved in Xanthan Gum Synthesis and Yellow Pigmentation

Novel rkp Gene Clusters of Sinorhizobium meliloti Involved in Capsular Polysaccharide Production and Invasion of the Symbiotic Nodule: the rkpK Gene Encodes a UDP-Glucose Dehydrogenase

Lipopolysaccharide biosynthesis in Xanthomonas campestris pv. campestris: a cluster of 15 genes is involved in the biosynthesis of the LPS O-antigen and the LPS core

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