A novel role for ECF-type sigma factors - Regulation of bacterial sulfite oxidation

Kappler, Ulrike, Tan, Chelsea, Ganskow, Stefanie and Broadbent, Sarah (2011). A novel role for ECF-type sigma factors - Regulation of bacterial sulfite oxidation. In: Proceedings of the ASM 2011 Hobart - Microbiology on the Edge. ASM 2011 Hobart: Microbiology on the Edge, Hobart, Australia, (). 4-8 July 2011.

Author Kappler, Ulrike
Tan, Chelsea
Ganskow, Stefanie
Broadbent, Sarah
Title of paper A novel role for ECF-type sigma factors - Regulation of bacterial sulfite oxidation
Language of Title eng
Conference name ASM 2011 Hobart: Microbiology on the Edge
Conference location Hobart, Australia
Conference dates 4-8 July 2011
Proceedings title Proceedings of the ASM 2011 Hobart - Microbiology on the Edge
Language of Proceedings Title eng
Language of Journal Name eng
Place of Publication South Melbourne, Vic., Australia
Publisher The Australian Society for Microbiology
Publication Year 2011
Year available 2011
Sub-type Published abstract
Total pages 1
Collection year 2012
Language eng
Formatted Abstract/Summary
Extracytoplasmic function (ECF) sigma factors are one of the key mechanisms of bacterial signal transduction and form a large and diverse protein family with over 40, mostly unstudied subfamilies (1). We have uncovered a novel role for an ECF sigma factor from a so far unstudied ECF subfamily (ECF26). Our work indicates that ECF26 sigma factors are involved in regulating sulfite oxidation in bacteria with very different types of sulfur metabolism, namely a chemolithotrophic sulfur oxidizer, Starkeya novella, and the organosulfur compound degrading bacterium Sinorhizobium meliloti, both of which highly express sulfite oxidizing enzymes when growing on the respective sulfur substrates. In both cases we were able to show that upregulation of sulfite oxidation occurs in response to exposure to sulfite, rather than in response to metabolizable sulfur substrates thiosulfate and taurine), indicating that the sulfite oxidizing enzymes are not integrated into the respective sulfur oxidation pathways. Neither of the two sigma factors showed any evidence for autoregulation, but in both cases the encoding genes are found upstream of genes encoding membrane-bound anti-sigma factors. The target genes share a common promoter consensus sequence, however, experiment using GFP fusions showed that the sigma factors are specific to the target promoters from the same species. Taken together these data clearly show for the first time a physiological role for two ECF26 sigma factors, and also indicate that sulfite oxidation in bacteria is not part of dissimilatory energy generation but is likely to be part of a sulfur stress response.


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Q-Index Status Provisional Code
Institutional Status UQ

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Created: Fri, 09 Mar 2012, 09:58:48 EST by Lucy O'Brien on behalf of School of Chemistry & Molecular Biosciences