Article Abstract:
DNA library screening of TnphoA insertion mutants for iron-repressed fusions to phoA led to the selection and cloning of the Bordetella bronchiseptica ferric iron repressed outer-membrane protein (bfrA) gene. Sequence analysis of the 80-kDa gene product revealed that it is homologous to a number of bacterial proteins belonging to the family of Ton B-dependent outer membrane receptors. bfrA gene expression was found to be induced by low iron availability under the control of the promoter that is overlapped by a sequence resembling a consensus Fur-binding sequence.
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Article Abstract:
The Bordetella ferric enterobactin (bfeA) receptor gene of Bordetella pertussis is necessary for the utilization of enterobactin to obtain the iron required for growth. The protein encoded by bfeA is structurally similar to the enterobactin receptors fepA and pfeA produced by Escherichia coli and Pseudomonas aeruginosa respectively. Deficiency of iron induces the expression of bfeA which is unaffected by the addition of enterobactin. Bordetella cells containing an inactive bfeA are unable to grow in the presence of enterobactin.
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Article Abstract:
Disruption of the tonB gene in Bordetella pertussis and Bordetella bronchiseptica is discussed. The disruption prevents utilization of hemin and hemoglobin, ferric siderophores, as iron sources. The B. bronchiseptica tonB gene was cloned by detection of a chromosomal restriction fragment hybridizing with each of two degenerate oligonucleotides that correspond to Pro-Glu and Pro-Lys repeats characteristic of known TonB proteins.
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