Previous Article | Next Article 
J Bacteriol, April 1998, p. 1729-1740, Vol. 180, No. 7
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
The Rhizobium etli rpoN Locus: DNA
Sequence Analysis and Phenotypical Characterization of rpoN,
ptsN, and ptsA Mutants
Jan
Michiels,
Tom
Van
Soom,
Inge
D'hooghe,
Bruno
Dombrecht,
Traki
Benhassine,
Petra
de Wilde, and
Jos
Vanderleyden*
F. A. Janssens Laboratory of Genetics,
K. U. Leuven, B-3001 Heverlee, Belgium
Received 31 October 1997/Accepted 16 January 1998
The rpoN region of Rhizobium etli was
isolated by using the Bradyrhizobium japonicum rpoN1 gene
as a probe. Nucleotide sequence analysis of a 5,600-bp DNA fragment of
this region revealed the presence of four complete open reading frames
(ORFs), ORF258, rpoN, ORF191, and ptsN, coding
for proteins of 258, 520, 191, and 154 amino acids, respectively. The
gene product of ORF258 is homologous to members of the ATP-binding
cassette-type permeases. ORF191 and ptsN are homologous to
conserved ORFs found downstream from rpoN genes in other
bacterial species. Unlike in most other microorganisms,
rpoN and ORF191 are separated by approximately 1.6 kb. The
R. etli rpoN gene was shown to control in free-living conditions the production of melanin, the activation of
nifH, and the metabolism of C4-dicarboxylic
acids and several nitrogen sources (ammonium, nitrate, alanine, and
serine). Expression of the rpoN gene was negatively
autoregulated and occurred independently of the nitrogen source.
Inactivation of the ptsN gene resulted in a decrease of
melanin synthesis and nifH expression. In a search for
additional genes controlling the synthesis of melanin, an R. etli mutant carrying a Tn5 insertion in
ptsA, a gene homologous to the Escherichia coli
gene coding for enzyme I of the phosphoenolpyruvate:sugar phosphotransferase system, was obtained. The R. etli ptsA
mutant also displayed reduced expression of nifH. The
ptsN and ptsA mutants also displayed increased
sensitivity to the toxic effects of malate and succinate. Growth of
both mutants was inhibited by these C4-dicarboxylates at 20 mM at pH 7.0, while wild-type cells grow normally under these
conditions. The effect of malate occurred independently of the nitrogen
source used. Growth inhibition was decreased by lowering the pH of the
growth medium. These results suggest that ptsN and
ptsA are part of the same regulatory cascade, the
inactivation of which renders the cells sensitive to toxic effects of
elevated concentrations of malate or succinate.
*
Corresponding author. Mailing address: F.A. Janssens
Laboratory of Genetics, K.U. Leuven, Kardinaal Mercierlaan 92, B-3001 Heverlee, Belgium. Phone: 32 16 321631. Fax: 32 16 321966. E-mail: jozef.vanderleyden{at}agr.kuleuven.ac.be.

Present address: Laboratoire de Biologie Moléculaire,
Institut Pasteur d'Algérie, Alger, Algeria.
This article has been cited by other articles:
-
Fauvart, M., Verstraeten, N., Dombrecht, B., Venmans, R., Beullens, S., Heusdens, C., Michiels, J.
(2009). Rhizobium etli HrpW is a pectin-degrading enzyme and differs from phytopathogenic homologues in enzymically crucial tryptophan and glycine residues. Microbiology
155: 3045-3054
[Abstract]
[Full Text]
-
Chatfield, C. H., Cianciotto, N. P.
(2007). The Secreted Pyomelanin Pigment of Legionella pneumophila Confers Ferric Reductase Activity. Infect. Immun.
75: 4062-4070
[Abstract]
[Full Text]
-
Pfluger, K., de Lorenzo, V.
(2007). Growth-dependent Phosphorylation of the PtsN (EIINtr) Protein of Pseudomonas putida. J. Biol. Chem.
282: 18206-18211
[Abstract]
[Full Text]
-
Velazquez, F., Pfluger, K., Cases, I., De Eugenio, L. I., de Lorenzo, V.
(2007). The Phosphotransferase System Formed by PtsP, PtsO, and PtsN Proteins Controls Production of Polyhydroxyalkanoates in Pseudomonas putida. J. Bacteriol.
189: 4529-4533
[Abstract]
[Full Text]
-
Deutscher, J., Francke, C., Postma, P. W.
(2006). How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria. Microbiol. Mol. Biol. Rev.
70: 939-1031
[Abstract]
[Full Text]
-
Daniels, R., Reynaert, S., Hoekstra, H., Verreth, C., Janssens, J., Braeken, K., Fauvart, M., Beullens, S., Heusdens, C., Lambrichts, I., De Vos, D. E., Vanderleyden, J., Vermant, J., Michiels, J.
(2006). Quorum signal molecules as biosurfactants affecting swarming in Rhizobium etli. Proc. Natl. Acad. Sci. USA
103: 14965-14970
[Abstract]
[Full Text]
-
Hernandez-Romero, D., Solano, F., Sanchez-Amat, A.
(2005). Polyphenol Oxidase Activity Expression in Ralstonia solanacearum. Appl. Environ. Microbiol.
71: 6808-6815
[Abstract]
[Full Text]
-
Moris, M., Braeken, K., Schoeters, E., Verreth, C., Beullens, S., Vanderleyden, J., Michiels, J.
(2005). Effective Symbiosis between Rhizobium etli and Phaseolus vulgaris Requires the Alarmone ppGpp. J. Bacteriol.
187: 5460-5469
[Abstract]
[Full Text]
-
Aguilar, O. M., Riva, O., Peltzer, E.
(2004). Analysis of Rhizobium etli and of its symbiosis with wild Phaseolus vulgaris supports coevolution in centers of host diversification. Proc. Natl. Acad. Sci. USA
101: 13548-13553
[Abstract]
[Full Text]
-
Moris, M., Dombrecht, B., Xi, C., Vanderleyden, J., Michiels, J.
(2004). Regulatory Role of Rhizobium etli CNPAF512 fnrN during Symbiosis. Appl. Environ. Microbiol.
70: 1287-1296
[Abstract]
[Full Text]
-
Warner, J. B., Lolkema, J. S.
(2003). CcpA-Dependent Carbon Catabolite Repression in Bacteria. Microbiol. Mol. Biol. Rev.
67: 475-490
[Abstract]
[Full Text]
-
Stafford, G. P., Scanlan, J., McDonald, I. R., Murrell, J. C.
(2003). rpoN, mmoR and mmoG, genes involved in regulating the expression of soluble methane monooxygenase in Methylosinus trichosporium OB3b. Microbiology
149: 1771-1784
[Abstract]
[Full Text]
-
Daniels, R., De Vos, D. E., Desair, J., Raedschelders, G., Luyten, E., Rosemeyer, V., Verreth, C., Schoeters, E., Vanderleyden, J., Michiels, J.
(2002). The cin Quorum Sensing Locus of Rhizobium etli CNPAF512 Affects Growth and Symbiotic Nitrogen Fixation. J. Biol. Chem.
277: 462-468
[Abstract]
[Full Text]
-
Hendrickson, E. L., Plotnikova, J., Mahajan-Miklos, S., Rahme, L. G., Ausubel, F. M.
(2001). Differential Roles of the Pseudomonas aeruginosa PA14 rpoN Gene in Pathogenicity in Plants, Nematodes, Insects, and Mice. J. Bacteriol.
183: 7126-7134
[Abstract]
[Full Text]
-
Cases, I., Velazquez, F., de Lorenzo, V.
(2001). Role of ptsO in Carbon-Mediated Inhibition of the Pu Promoter Belonging to the pWW0 Pseudomonas putida Plasmid. J. Bacteriol.
183: 5128-5133
[Abstract]
[Full Text]
-
Mouz, S., Coursange, E., Toussaint, A.
(2001). Ralstonia metallidurans CH34 RpoN sigma factor and the control of nitrogen metabolism and biphenyl utilization. Microbiology
147: 1947-1954
[Abstract]
[Full Text]
-
Cases, I., Lopez, J.-A., Albar, J.-P., De Lorenzo, V.
(2001). Evidence of Multiple Regulatory Functions for the PtsN (IIANtr) Protein of Pseudomonas putida. J. Bacteriol.
183: 1032-1037
[Abstract]
[Full Text]
-
Xi, C., Schoeters, E., Vanderleyden, J., Michiels, J.
(2000). Symbiosis-specific expression of Rhizobium etli casA encoding a secreted calmodulin-related protein. Proc. Natl. Acad. Sci. USA
10.1073/pnas.210181097v1
[Abstract]
[Full Text]
-
Buck, M., Gallegos, M.-T., Studholme, D. J., Guo, Y., Gralla, J. D.
(2000). The Bacterial Enhancer-Dependent sigma 54 (sigma N) Transcription Factor. J. Bacteriol.
182: 4129-4136
[Full Text]
-
Rabus, R., Reizer, J., Paulsen, I., Saier, M. H. Jr.
(1999). Enzyme INtr from Escherichia coli. A NOVEL ENZYME OF THE PHOSPHOENOLPYRUVATE-DEPENDENT PHOSPHOTRANSFERASE SYSTEM EXHIBITING STRICT SPECIFICITY FOR ITS PHOSPHORYL ACCEPTOR, NPr. J. Biol. Chem.
274: 26185-26191
[Abstract]
[Full Text]
-
Cases, I., Perez-Martin, J., de Lorenzo, V.
(1999). The IIANtr (PtsN) Protein of Pseudomonas putida Mediates the C Source Inhibition of the sigma 54-dependent Pu Promoter of the TOL Plasmid. J. Biol. Chem.
274: 15562-15568
[Abstract]
[Full Text]
-
Michiels, J., Moris, M., Dombrecht, B., Verreth, C., Vanderleyden, J.
(1998). Differential Regulation of Rhizobium etli rpoN2 Gene Expression during Symbiosis and Free-Living Growth. J. Bacteriol.
180: 3620-3628
[Abstract]
[Full Text]
-
King, N. D., O'Brian, M. R.
(2001). Evidence for Direct Interaction between Enzyme INtr and Aspartokinase to Regulate Bacterial Oligopeptide Transport. J. Biol. Chem.
276: 21311-21316
[Abstract]
[Full Text]
-
Xi, C., Schoeters, E., Vanderleyden, J., Michiels, J.
(2000). Symbiosis-specific expression of Rhizobium etli casA encoding a secreted calmodulin-related protein. Proc. Natl. Acad. Sci. USA
97: 11114-11119
[Abstract]
[Full Text]