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Sinorhizobium medicae genes whose regulation involves the ActS and/or ActR signal transduction proteins


Fenner, BJ and Tiwari, RP and Reeve, WG and Dilworth, MJ and Glenn, AR, Sinorhizobium medicae genes whose regulation involves the ActS and/or ActR signal transduction proteins, FEMS Microbiology Letters, 236, (1) pp. 21-31. ISSN 0378-1097 (2004) [Refereed Article]

DOI: doi:10.1016/j.femsle.2004.05.016


ActS-ActR proteins belong to a highly conserved family of two-component signal transduction systems involved in global regulation in the α-proteobacteria; they were first identified in Sinorhizobium medicae (previously Sinorhizobium meliloti) as essential for acid-tolerance. This paper reports on the identification of genes regulated by ActS and/or ActR in S. medicae. To do this, random gusA fusions were created in S. medicae to follow gene transcription in an actS chromosomal knockout mutant containing plasmid-borne actS. Plasmid borne actS was cured from the mutants and β-glucuronidase (GUS) activity compared between the different genetic backgrounds. We detected actS-dependent regulation of the genes gst1 (detoxification), hyuA (hydantoin utilization) and fixN2 (microaerobic respiration). We show that ActR is involved in regulating cbbS (CO2 fixation), narB (nitrate assimilation) and required for low pH and microaerobic induction of the nitrogen fixation regulators fixK and nifA. In particular, we demonstrate that the transcriptional activation of fixN2 is regulated by ActR through FixK. © 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.

Item Details

Item Type:Refereed Article
Research Division:Environmental Sciences
Research Group:Soil sciences
Research Field:Soil sciences not elsewhere classified
Objective Division:Plant Production and Plant Primary Products
Objective Group:Horticultural crops
Objective Field:Horticultural crops not elsewhere classified
UTAS Author:Glenn, AR (Professor Andrew Glenn)
ID Code:33139
Year Published:2004
Web of Science® Times Cited:20
Deposited By:Research Division
Deposited On:2004-08-01
Last Modified:2005-07-02

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