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

 Previous Article  |  Next Article 

J. Bacteriol., 12 1996, 7234-7240, Vol 178, No. 24
Copyright © 1996, American Society for Microbiology

Lrp is a direct repressor of the dad operon in Escherichia coli

E Mathew, J Zhi and M Freundlich
Department of Biochemistry and Cell Biology, State University of New York, Stony Brook 11794, USA.

Expression of the degradative D-amino acid dehydrogenase (dad) operon is known to be increased when Escherichia coli is grown in the presence of D- or L-alanine. Alanine is thought to act as an inducer to block the action of a postulated repressor. This operon is also believed to be regulated by catabolite repression. We have used in vivo and in vitro experiments that show that the dad repressor is the leucine- responsive regulatory protein (Lrp). dad expression in a dad-lacZ operon fusion strain was increased four- to sevenfold when cells were grown in minimal medium containing alanine or leucine. A strain lacking Lrp had high-level constitutive dad expression. Gel retardation and footprinting studies revealed that Lrp binds in vitro to multiple sites over a large area in the dad promoter region. This binding was reduced by alanine or leucine. In vitro transcription assays, using a plasmid template and primer extension analysis, identified three major dad transcripts (Tr1, Tr2, and Tr3). The formation of these transcripts was differentially regulated by cyclic AMP-cyclic AMP receptor protein complex, and each was strongly repressed by Lrp. Alanine or leucine completely (for Tr1 and Tr2) or partially (for Tr3) reversed Lrp inhibition. Site-directed mutagenesis of an Lrp binding site strongly reduced Lrp binding and prevented Lrp repression of dad transcription in vivo and in vitro. Taken together, these results strongly suggest that Lrp and alanine or leucine act directly to repress and induce, respectively, transcription of the dad operon.


This article has been cited by other articles:

  • Boulette, M. L., Baynham, P. J., Jorth, P. A., Kukavica-Ibrulj, I., Longoria, A., Barrera, K., Levesque, R. C., Whiteley, M. (2009). Characterization of Alanine Catabolism in Pseudomonas aeruginosa and Its Importance for Proliferation In Vivo. J. Bacteriol. 191: 6329-6334 [Abstract] [Full Text]  
  • Bodini, S., Nunziangeli, L., Santori, F. (2007). Influence of Amino Acids on Low-Density Escherichia coli Responses to Nutrient Downshifts. J. Bacteriol. 189: 3099-3105 [Abstract] [Full Text]  
  • Shultzaberger, R. K., Chen, Z., Lewis, K. A., Schneider, T. D. (2007). Anatomy of Escherichia coli {sigma}70 promoters. Nucleic Acids Res 35: 771-788 [Abstract] [Full Text]  
  • Sprusansky, O., Stirrett, K., Skinner, D., Denoya, C., Westpheling, J. (2005). The bkdR Gene of Streptomyces coelicolor Is Required for Morphogenesis and Antibiotic Production and Encodes a Transcriptional Regulator of a Branched-Chain Amino Acid Dehydrogenase Complex. J. Bacteriol. 187: 664-671 [Abstract] [Full Text]  
  • Lodwig, E., Kumar, S., Allaway, D., Bourdes, A., Prell, J., Priefer, U., Poole, P. (2004). Regulation of L-Alanine Dehydrogenase in Rhizobium leguminosarum bv. viciae and Its Role in Pea Nodules. J. Bacteriol. 186: 842-849 [Abstract] [Full Text]  
  • Brinkman, A. B., Bell, S. D., Lebbink, R. J., de Vos, W. M., van der Oost, J. (2002). The Sulfolobus solfataricus Lrp-like Protein LysM Regulates Lysine Biosynthesis in Response to Lysine Availability. J. Biol. Chem. 277: 29537-29549 [Abstract] [Full Text]  
  • Zinser, E. R., Kolter, R. (2000). Prolonged Stationary-Phase Incubation Selects for lrp Mutations in Escherichia coli K-12. J. Bacteriol. 182: 4361-4365 [Abstract] [Full Text]  
  • Weyand, N. J., Low, D. A. (2000). Regulation of Pap Phase Variation. Lrp IS SUFFICIENT FOR THE ESTABLISHMENT OF THE PHASE OFF pap DNA METHYLATION PATTERN AND REPRESSION OF pap TRANSCRIPTION IN VITRO. J. Biol. Chem. 275: 3192-3200 [Abstract] [Full Text]  
  • Janes, B. K., Bender, R. A. (1999). Two Roles for the Leucine-Responsive Regulatory Protein in Expression of the Alanine Catabolic Operon (dadAB) in Klebsiella aerogenes. J. Bacteriol. 181: 1054-1058 [Abstract] [Full Text]  
  • Berlyn, M. K. B. (1998). Linkage Map of Escherichia coli K-12, Edition 10: The Traditional Map. Microbiol. Mol. Biol. Rev. 62: 814-984 [Abstract] [Full Text]  
  • Rosemeyer, V., Michiels, J., Verreth, C., Vanderleyden, J. (1998). luxI- and luxR-Homologous Genes of Rhizobium etli CNPAF512 Contribute to Synthesis of Autoinducer Molecules and Nodulation of Phaseolus vulgaris. J. Bacteriol. 180: 815-821 [Abstract] [Full Text]  
  • Janes, B. K., Bender, R. A. (1998). Alanine Catabolism in Klebsiella aerogenes: Molecular Characterization of the dadAB Operon and Its Regulation by the Nitrogen Assimilation Control Protein. J. Bacteriol. 180: 563-570 [Abstract] [Full Text]  
  • Brinkman, A. B., Dahlke, I., Tuininga, J. E., Lammers, T., Dumay, V., de Heus, E., Lebbink, J. H. G., Thomm, M., de Vos, W. M., van der Oost, J. (2000). An Lrp-like Transcriptional Regulator from the Archaeon Pyrococcus furiosus Is Negatively Autoregulated. J. Biol. Chem. 275: 38160-38169 [Abstract] [Full Text]