This Article Full Text Full Text (PDF) Supplemental material 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 Carl, B. Articles by Fetzner, S. Search for Related Content PubMed PubMed Citation Articles by Carl, B. Articles by Fetzner, S. Agricola Articles by Carl, B. Articles by Fetzner, S.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, December 2005, p. 8618-8626, Vol. 71, No. 12
0099-2240/05/$08.00+0     doi:10.1128/AEM.71.12.8618-8626.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Transcriptional Activation of Quinoline Degradation Operons of Pseudomonas putida 86 by the AraC/XylS-Type Regulator OxoS and Cross-Regulation of the PqorM Promoter by XylS

Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Corrensstraße 3, D-48149 Münster, Germany

Received 24 May 2005/ Accepted 4 August 2005

The quinoline-degradative gene cluster (oxoO, open reading frames 1 to 6 [ORF1 to -6], qorMSL, ORF7 to -9, oxoR) of Pseudomonas putida 86 consists of several overlapping operons controlled in response to quinoline by the master promoter PoxoO and internal promoters Porf3, PqorM, and PoxoR. ORF7 to -9, presumed to be important for maturation of the molybdenum hydroxylase quinoline 2-oxidoreductase, are also weakly transcribed independently of quinoline. Expression of the oxoS gene, located upstream of oxoO, is not influenced by the carbon source. OxoS shows 26% amino acid sequence identity to XylS, the transcriptional regulator of the meta pathway promoter Pm of TOL plasmid pWW0, and is required for quinoline-dependent transcription from PoxoO, Porf3, PqorM, and PoxoR. 5' deletion analysis of PoxoO and PqorM suggested that a 5'-TGCPuCT-N₃-GGGATA-3' motif, which resembles the distal 5'-TGCA-N₆-GGNTA-3' half-site of the tandem XylS binding site, is essential for oxoS-dependent transcriptional activation. PqorM, which shows similarity to the tandem XylS recognition site of Pm, was cross-activated by the xylS gene product in response to benzoate. The distal half-site of PqorM is necessary, but probably not sufficient, for transcriptional activation by XylS. Despite conservation in PoxoO of a distal 5'-TGCA-N₆-GGNTA-3' sequence, cross-activation of PoxoO by XylS and benzoate was not observed. The oxoS gene product in the presence of quinoline weakly stimulated transcription from the Pm promoter. Involvement of an XylS-type protein in the regulation of genes encoding synthesis of a molybdenum hydroxylase is without precedent and may reflect the evolutionary origin of this pathway in the metabolism of aromatic compounds.

Supplemental material for this article may be found at http://aem.asm.org/.

This article has been cited by other articles:

• Parschat, K., Overhage, J., Strittmatter, A. W., Henne, A., Gottschalk, G., Fetzner, S. (2007). Complete Nucleotide Sequence of the 113-Kilobase Linear Catabolic Plasmid pAL1 of Arthrobacter nitroguajacolicus Ru61a and Transcriptional Analysis of Genes Involved in Quinaldine Degradation. J. Bacteriol. 189: 3855-3867 [Abstract] [Full Text]