Analysis of the Rhizobium leguminosarum siderophore-uptake gene fhuA:Differential expression in free-living bacteria and nitrogen-fixing bacteroids and distribution of an fhuA pseudogene in different strains

Yeoman, Kay H., Wisniewski-Dye, Florence, Timony, Christopher, Stevens, James B., DeLuca, Nicola G., Downie, J. Allan and Johnston, Andrew W. B. (2000) Analysis of the Rhizobium leguminosarum siderophore-uptake gene fhuA:Differential expression in free-living bacteria and nitrogen-fixing bacteroids and distribution of an fhuA pseudogene in different strains. Microbiology, 146 (4). pp. 829-837. ISSN 1350-0872

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Abstract

A mutation was isolated in the Rhizobium leguminosarum gene fhuA, which appears to specify the outer-membrane receptor for the siderophore vicibactin. The mutant was defective in iron uptake and accumulated the siderophore vicibactin in the extracellular medium. Expression of fhuA was regulated by Fe3+, transcription being higher in iron-depleted cells. Transcription of fhuA was independent of a functional copy of rpol, a neighbouring gene that specifies a putative ECF sigma factor of RNA polymerase and which is involved in siderophore production in Rhizobium. Mutations in fhuA did not detectably affect symbiotic N2 fixation on peas. An fhuA::gus fusion was expressed by bacteria in the meristematic zone of pea nodules but not in mature bacteroids. Some other strains of R. leguminosarum also contain a pseudogene version of fhuA. The sequences of some of these and the 'real' fhuA genes were determined.

Item Type: Article
Uncontrolled Keywords: ecf,σ factor,fhu genes,iron-medicated regulation,pseudogene,rhiozbia,siderophores
Faculty \ School: Faculty of Science > School of Biological Sciences
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Depositing User: Pure Connector
Date Deposited: 26 Nov 2013 12:38
Last Modified: 23 Sep 2020 23:36
URI: https://ueaeprints.uea.ac.uk/id/eprint/44539
DOI: 10.1099/00221287-146-4-829

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