Identification and Characterization of alcR a Gene Encoding an AraC-Like Regulator of Alcaligin Siderophore Biosynthesis and Transport in Bordetella pertussis and Bordetella bronchiseptica

ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)
Sandra K. Armstrong (Creator)
Fiona C. Beaumont (Creator)
Timothy J. Brickman (Creator)
Ho Young Kang (Creator)
Institution
East Carolina University (ECU )
Web Site: http://www.ecu.edu/lib/

Abstract: A Bordetella bronchiseptica iron transport mutant was isolated following an enrichment procedure based on streptonigrin resistance. The mutant displayed a growth defect on iron-restricted medium containing ferric alcaligin as the sole iron source. In addition to the apparent inability to acquire iron from the siderophore the mutant failed to produce alcaligin as well as two known iron-regulated proteins one of which is the AlcC alcaligin biosynthesis protein. A 1.6-kb KpnI-PstI Bordetella pertussis DNA fragment mapping downstream of the alcaligin biosynthesis genes alcABC restored both siderophore biosynthesis and expression of the ironregulated proteins to the mutant. Nucleotide sequencing of this complementing 1.6-kb region identified an open reading frame predicted to encode a protein with strong similarity to members of the AraC family of transcriptional regulators for which we propose the gene designation alcR. Primer extension analysis localized an iron-regulated transcription initiation site upstream of the alcR open reading frame and adjacent to sequences homologous to the consensus Fur repressor binding site. The AlcR protein was produced by using an Escherichia coli expression system and visualized in electrophoretic gels. In-frame alcR deletion mutants of B. pertussis and B. bronchiseptica were constructed and the defined mutants exhibited the alcR mutant phenotype characterized by the inability to produce and transport alcaligin and express the two iron-repressed proteins. The cloned alcR gene provided in trans restored these siderophore system activities to the mutants. Together these results indicate that AlcR is involved in the regulation of Bordetella alcaligin biosynthesis and transport genes and is required for their full expression. Originally published Journal of Bacteriology Vol. 180 No. 4 Feb 1998

Additional Information

Publication
Other
Journal of Bacteriology. 180:4(February 1998) p. 862-870.
Language: English
Date: 2011
Keywords
Bordetella bronchiseptica, siderophore, alcaligin

Email this document to

This item references:

TitleLocation & LinkType of Relationship
Identification and Characterization of alcR a Gene Encoding an AraC-Like Regulator of Alcaligin Siderophore Biosynthesis and Transport in Bordetella pertussis and Bordetella bronchisepticahttp://hdl.handle.net/10342/3448The described resource references, cites, or otherwise points to the related resource.