A 3.9-kb DNA region of Xanthomonas campestris pv. campestris that is necessary for lipopolysaccharide production encodes a set of enzymes involved in the synthesis of dTDP-rhamnose.
By mutational analysis it was found that a 3.9-kb SmaI-XhoII DNA fragment of Xanthomonas campestris pv. campestris is involved in lipopolysaccharide (LPS) biosynthesis. LPS samples isolated from different mutants carrying mutations in the 3.9-kb SmaI-XhoII DNA fragment exhibited banding patterns in silver-stained sodium dodecyl sulfate-polyacrylamide gels markedly different from that of the wild-type LPS. Moreover, comparison of the monosaccharide composition obtained by high-performance anion-exchange chromatography with pulsed amperometric detection of LPS purified from wild-type Xanthomonas campestris pv. campestris B100 and from mutants with mutations in the 3.9-kb SmaI-XhoII DNA fragment revealed a lack of rhamnose moieties in the mutant LPS. Sequence analysis of this DNA fragment revealed four open reading frames (ORFs), designated ORF302, ORF183, ORF295, and ORF351. The deduced amino acid sequences of these ORFs showed a high degree of homology to the deduced amino acid sequences of the rfbC, rfbD, rfbA, and rfbB genes of Salmonella typhimurium LT2, which have been shown to encode a set of enzymes responsible for conversion of glucose 1-phosphate to dTDP-rhamnose.
Köplin
R
R
Lehrstuhl für Genetik, Universität Bielefeld, Germany.
Wang
G
G
Hötte
B
B
Priefer
U B
UB
Pühler
A
A
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D008070:Lipopolysaccharides / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000302:isolation & purification; D009702:Nucleoside Diphosphate Sugars / Q000096:biosynthesis*; D016366:Open Reading Frames; D015183:Restriction Mapping; D012486:Salmonella typhimurium / Q000201:enzymology / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013942:Thymine Nucleotides / Q000096:biosynthesis*; D016959:Xanthomonas campestris / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*
D004269:DNA, Bacterial; D008070:Lipopolysaccharides; D009005:Monosaccharides; D009702:Nucleoside Diphosphate Sugars; D013942:Thymine Nucleotides; C073293:thymidine diphosphate rhamnose