This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Arsène-Ploetze, F. Articles by Bringel, F. Search for Related Content PubMed PubMed Citation Articles by Arsène-Ploetze, F. Articles by Bringel, F.

 Previous Article  |  Next Article 

Journal of Bacteriology, July 2006, p. 4777-4786, Vol. 188, No. 13
0021-9193/06/$08.00+0     doi:10.1128/JB.00195-06
Copyright © 2006, American Society for Microbiology. All Rights Reserved.

Uracil Salvage Pathway in Lactobacillus plantarum: Transcription and Genetic Studies

Florence Arsène-Ploetze,¹ Hervé Nicoloff,^1, Benoît Kammerer,¹ Jan Martinussen,² and Françoise Bringel^1*

UMR7156 Université Louis Pasteur/CNRS, Génétique Moléculaire, Génomique, Microbiologie, 28 rue Goethe, F-67083 Strasbourg, France,¹ Biocentrum-DTU, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark²

Received 6 February 2006/ Accepted 16 April 2006

The uracil salvage pathway in Lactobacillus plantarum was demonstrated to be dependent on the upp-pyrP gene cluster. PyrP was the only high-affinity uracil transporter since a pyrP mutant no longer incorporated low concentrations of radioactively labeled uracil and had increased resistance to the toxic uracil analogue 5-fluorouracil. The upp gene encoded a uracil phosphoribosyltransferase (UPRT) enzyme catalyzing the conversion of uracil and 5-phosphoribosyl--1-pyrophosphate to UMP and pyrophosphate. Analysis of mutants revealed that UPRT is a major cell supplier of UMP synthesized from uracil provided by preformed nucleic acid degradation. In a mutant selection study, seven independent upp mutants were isolated and all were found to excrete low amounts of pyrimidines to the growth medium. Pyrimidine-dependent transcription regulation of the biosynthetic pyrimidine pyrR1-B-C-Aa1-Ab1-D-F-E operon was impaired in the upp mutants. Despite the fact that upp and pyrP are positioned next to each other on the chromosome, they are not cotranscribed. Whereas pyrP is expressed as a monocistronic message, the upp gene is part of the lp_2376-glyA-upp operon. The lp_2376 gene encodes a putative protein that belongs to the conserved protein family of translation modulators such as Sua5, YciO, and YrdC. The glyA gene encodes a putative hydroxymethyltransferase involved in C₁ unit charging of tetrahydrofolate, which is required in the biosynthesis of thymidylate, pantothenate, and purines. Unlike upp transcription, pyrP transcription is regulated by exogenous pyrimidine availability, most likely by the same mechanism of transcription attenuation as that of the pyr operon.

Present address: Center for Adaptation Genetics and Drug Resistance, Departments of Molecular Biology and Microbiology, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111.

This article has been cited by other articles:

• Bringel, F., Hammann, P., Kugler, V., Arsene-Ploetze, F. (2008). Lactobacillus plantarum response to inorganic carbon concentrations: PyrR2-dependent and -independent transcription regulation of genes involved in arginine and nucleotide metabolism. Microbiology 154: 2629-2640 [Abstract] [Full Text]  
• Arsene-Ploetze, F., Kugler, V., Martinussen, J., Bringel, F. (2006). Expression of the pyr Operon of Lactobacillus plantarum Is Regulated by Inorganic Carbon Availability through a Second Regulator, PyrR2, Homologous to the Pyrimidine-Dependent Regulator PyrR1. J. Bacteriol. 188: 8607-8616 [Abstract] [Full Text]