1887

Abstract

The synthesis of extracellular enzymes and extracellular polysaccharide (EPS) in pathovar () is subject to co-ordinate regulation by a cluster of genes called (for egulation of athogenicity actors). These genes are located within a 219 kb region of the chromosome isolated as the cosmid clone pIJ3020. The genes in the left-hand section of this region of the chromosome have previously been characterized. This paper reports on the genes in the right-hand section and on the phenotypes of mutants with transposon insertions in these genes. Sequence analysis identified eight genes or ORFs with the gene order . RecJ and GreA have established functions in recombination and transcriptional elongation, respectively. encoded a protein with some amino acid sequence relatedness to a hypothetical protein from and an autolysin response regulator in . The predicted protein products of , and were related to each other and had substantial amino acid sequence relatedness to hypothetical proteins from . Transposon insertions in , and had no effect on the synthesis of extracellular enzymes or EPS. The predicted proteins RpfE and Orf4 showed the highest amino acid sequence relatedness to hypothetical proteins from and , respectively. Transposon insertions in led to reduced levels of some extracellular enzymes (endoglucanase and protease) and increased levels of others (polygalacturonate lyase). Transposon insertions in had no effect on polygalacturonate lyase but led to reduced levels of protease and endoglucanase. Levels of EPS were reduced in both and mutants. These alterations in the levels of extracellular enzymes, which were relatively modest (between two- and threefold), did not affect the pathogenicity of on turnip. It is proposed that the gene designation should be for .

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2000-04-01
2024-12-14
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References

  1. Altschul S. F., Gish W., Miller W., Myers E. W., Lipman D. P. 1990; Basic local alignment search tool. J Mol Biol 215:403–410 [CrossRef]
    [Google Scholar]
  2. Barber C. E., Tang J.-L., Feng J.-X., Pan M.-Q., Wilson T. J. G., Slater H., Dow J. M., Williams P., Daniels M. J. 1997; A novel regulatory system required for pathogenicity of Xanthomonas campestris is mediated by a small diffusible signal molecule. Mol Microbiol 24:555–566 [CrossRef]
    [Google Scholar]
  3. Bibb M. J., Findlay P. R., Johnson M. W. 1984; The relationship between base composition and codon usage in bacterial genes and its use for the simple and reliable identification of protein-coding sequences. Gene 30:157–166 [CrossRef]
    [Google Scholar]
  4. Borodovsky M., McIninch J. D. 1993; genmark: parallel gene recognition for both DNA strands. Comput Chem 17:123–133 [CrossRef]
    [Google Scholar]
  5. Collinge D. B., Milligan D. E., Dow J. M., Scofield G., Daniels M. J. 1987; Gene expression in Brassica campestris showing a hypersensitive response to the incompatible pathogen Xanthomonas campestris pv. vitians. Plant Mol Biol 8:405–414 [CrossRef]
    [Google Scholar]
  6. Daniels M. J., Barber C. E., Turner P. C., Cleary W. G., Sawczyc M. K. 1984; Isolation of mutants of Xanthomonas campestris pathovar campestris showing altered pathogenicity. J Gen Microbiol 130:2447–2455
    [Google Scholar]
  7. De Crècy-Lagard V., Glaser P., Lejeune P., Sismeiro O., Barber C. E., Daniels M. J., Danchin A. 1990; A Xanthomonas campestris pv. campestris protein similar to catabolite activation factor is involved in regulation of phytopathogenicity. J Bacteriol 172:5877–5883
    [Google Scholar]
  8. Devereux V., Haeberli P., Smithies O. 1984; A comprehensive set of sequence analysis programs for the VAX. Nucleic Acids Res 12:387–395 [CrossRef]
    [Google Scholar]
  9. Dow J. M., Daniels M. J. 1994; Pathogenicity determinants and global regulation of pathogenicity in Xanthomonas campestris pv. campestris. In Molecular and Cellular Mechanisms in Bacterial Pathogenesis of Plants and Animals pp. 29–41Edited by Dangl J. L. Berlin: Springer;
    [Google Scholar]
  10. Dow J. M., Scofield G., Trafford K., Turner P. C., Daniels M. J. 1987; A gene cluster in Xanthomonas campestris pv. campestris controls the excretion of polygalacturonate lyase and other enzymes. Physiol Mol Plant Pathol 31:261–271 [CrossRef]
    [Google Scholar]
  11. Dow J. M., Clarke B. R., Milligan D. E., Tang J. L., Daniels M. J. 1990; Extracellular proteases from Xanthomonas campestris pv. campestris, the black rot pathogen. Appl Environ Microbiol 56:2994–2998
    [Google Scholar]
  12. Gough C. L., Dow J. M., Barber C. E., Daniels M. J. 1988; Cloning of two endoglucanase genes from Xanthomonas campestris pv. campestris: role of the major enzyme in pathogenesis. Mol Plant–Microbe Interact 1:275–281 [CrossRef]
    [Google Scholar]
  13. Harris R. S., Ross K. J., Lombardo M. J., Rosenberg S. M. 1998; Mismatch repair in Escherichia coli cells lacking single-strand exonucleases ExoI, ExoVII, and RecJ. J Bacteriol 180:989–993
    [Google Scholar]
  14. Lu C. D., Kwon D. H., Abdelal A. T. 1997; Identification of greA encoding a transcriptional elongation factor as a member of the carA-orf-carB-greA operon in Pseudomonas aeruginosa PAO1. J Bacteriol 179:3043–3046
    [Google Scholar]
  15. Newman M.-A., Daniels M. J., Dow J. M. 1997; The activity of lipid A and core components of bacterial lipopolysaccharides in the prevention of the hypersensitive response in pepper. Mol Plant–Microbe Interact 10:926–928 [CrossRef]
    [Google Scholar]
  16. Onsando J. M. 1992; Black rot of crucifers. In Plant Diseases of International Importance. II: Diseases of Vegetable and Oil Seed Crops pp. 243–252Edited by Chaube H. S., Kumar J., Mukhopadhyay A. N., Singh U. S. Englewood Cliffs, NJ: Prentice Hall;
    [Google Scholar]
  17. Parker J. E., Barber C. E., Fan M.-J., Daniels M. J. 1993; Interaction of Xanthomonas campestris with Arabidopsis thaliana: characterization of a gene from X.c. pv. raphani that confers avirulence to most A. thaliana accessions. Mol Plant–Microbe Interact 6:216–224 [CrossRef]
    [Google Scholar]
  18. Rost B. 1996; PHD: predicting one-dimensional protein structure by profile-based neural networks. Methods Enzymol 266:525–539
    [Google Scholar]
  19. Shaw E. I., Mark G. L., Winkler H. H., Wood D. O. 1997; Transcriptional characterization of the Rickettsia prowazekii major macromolecular synthesis operon. J Bacteriol 179:6448–6452
    [Google Scholar]
  20. Slater H. 1999 The regulation of pathogenicity factor production in Xanthomonas campestris by a small diffusible molecule PhD thesis University of East Anglia;
    [Google Scholar]
  21. Staden R. 1996; The Staden sequence-analysis package. Mol Biotechnol 5:233–241 [CrossRef]
    [Google Scholar]
  22. Staskawicz B. J., Dahlbeck D., Keen N. T., Napoli C. 1987; Molecular characterization of cloned avirulence genes from race 0 and race 1 of Pseudomonas syringae pv. glycinea. J Bacteriol 169:5789–5794
    [Google Scholar]
  23. Tang J.-L., Gough C. L., Barber C. E., Dow J. M., Daniels M. J. 1987; Molecular cloning of protease gene(s) from Xanthomonas campestris pv. campestris: expression in Escherichia coli and role in pathogenicity. Mol Gen Genet 210:443–448 [CrossRef]
    [Google Scholar]
  24. Tang J.-L., Gough C. L., Daniels M. J. 1990; Cloning of genes involved in negative regulation of production of extracellular enzymes and polysaccharide of Xanthomonas campestris pathovar campestris. Mol Gen Genet 222:157–160
    [Google Scholar]
  25. Tang J.-L., Liu Y.-N., Barber C. E., Dow J. M., Wootton J. C., Daniels M. J. 1991; Genetic and molecular analysis of a cluster of rpf genes involved in positive regulation of synthesis of extracellular enzymes and polysaccharide in Xanthomonas campestris pathovar campestris. Mol Gen Genet 226:409–417
    [Google Scholar]
  26. Viswanathan M., Lovett S. T. 1998; Single-strand DNA-specific exonucleases in Escherichia coli: roles in repair and mutation avoidance. Genetics 149:7–16
    [Google Scholar]
  27. Vojnov A. A., Zorreguieta A., Dow J. M., Daniels M. J., Dankert M. A. 1998; Evidence for a role for the gumB and gumC gene products in the formation of xanthan from its pentasaccharide repeating unit by Xanthomonas campestris. Microbiology 144:1487–1493 [CrossRef]
    [Google Scholar]
  28. Wilson T. J. G., Bertrand N., Tang J.-L., Feng J.-X., Pan M.-Q., Barber C. E., Dow J. M., Daniels M. J. 1998; The rpfA gene of Xanthomonas campestris pathovar campestris which is involved in regulation of pathogenicity factor production encodes an aconitase. Mol Microbiol 28:961–970 [CrossRef]
    [Google Scholar]
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