HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Endoh, T. Articles by Omori, T. Search for Related Content PubMed PubMed Citation Articles by Endoh, T. Articles by Omori, T. Agricola Articles by Endoh, T. Articles by Omori, T.

A CysB-regulated and ⁵⁴-dependent regulator, SfnR, is essential for dimethyl sulfone metabolism of Pseudomonas putida strain DS1

Biotechnology Research Center, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan

Correspondence
Toshio Omori
aseigyo{at}mail.ecc.u-tokyo.ac.jp

Pseudomonas putida strain DS1 utilizes dimethyl sulfide (DMS) as a sulfur source, and desulfurizes it via dimethyl sulfoxide (DMSO), dimethyl sulfone (DMSO₂) and methanesulfonate (MSA). Its Tn5 mutant, Dfi74J, no longer utilized DMS, DMSO and DMSO₂, but could oxidize DMS to DMSO₂, suggesting that the conversion of DMSO₂ to MSA was interrupted in the mutant. Sequencing of the Tn5 flanking region of Dfi74J demonstrated that a gene, sfnR (designated for dimethyl sulfone utilization), encoding a transcriptional regulator containing an ATP-dependent ⁵⁴-association domain and a DNA-binding domain, was disrupted. sfnR is part of an operon with two other genes, sfnE and sfnC, located immediately upstream of sfnR and in the same orientation. The genes encode NADH-dependent FMN reductase (SfnE) and FMNH₂-dependent monooxygenase (SfnC). Complementation of Dfi74J with an sfnR-expressing plasmid led to restoration of its growth on DMS, DMSO and DMSO₂. An rpoN-defective mutant of strain DS1, which lacks the ⁵⁴ factor, grew on MSA, but not on DMS, DMSO and DMSO₂, indicating that SfnR controls expression of gene(s) involved in DMSO₂ metabolism by interaction with ⁵⁴-RNA polymerase. Northern hybridization and a reporter gene assay with an sfn–lacZ transcriptional fusion elucidated that expression of the sfnECR operon was induced under sulfate limitation and was dependent on a LysR-type transcriptional regulator, CysB. This is believed to be the first report that a ⁵⁴-dependent transcriptional regulator induced under sulfate limitation is involved in sulfur assimilation.

The DDBJ/EMBL/GenBank accession number for the sfnECR operon reported in this paper is AB091764.

This article has been cited by other articles:

				A. Kouzuma, T. Endoh, T. Omori, H. Nojiri, H. Yamane, and H. Habe Transcription Factors CysB and SfnR Constitute the Hierarchical Regulatory System for the Sulfate Starvation Response in Pseudomonas putida J. Bacteriol., July 1, 2008; 190(13): 4521 - 4531. [Abstract] [Full Text] [PDF]

				H. Habe, A. Kouzuma, T. Endoh, T. Omori, H. Yamane, and H. Nojiri Transcriptional regulation of the sulfate-starvation-induced gene sfnA by a {sigma}54-dependent activator of Pseudomonas putida Microbiology, September 1, 2007; 153(9): 3091 - 3098. [Abstract] [Full Text] [PDF]