Cloning and characterization of btr, a Bordetella pertussis gene encoding an FNR-like transcriptional regulator
Autor: | J D Bannan, J I MacInnes, Michael J. Moran, Richard L. Friedman, G A Soltes |
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Rok vydání: | 1993 |
Předmět: |
DNA
Bacterial Iron-Sulfur Proteins Bordetella pertussis Molecular Sequence Data Restriction Mapping Mutant Virulence medicine.disease_cause Hemolysis Microbiology Open Reading Frames Bacterial Proteins Gene expression Escherichia coli medicine Transcriptional regulation Animals Amino Acid Sequence Cloning Molecular Molecular Biology Gene Conserved Sequence DNA Primers Genomic Library Sheep Base Sequence Sequence Homology Amino Acid biology Escherichia coli Proteins Actinobacillus pleuropneumoniae Genetic Complementation Test Gene Expression Regulation Bacterial biology.organism_classification Molecular biology DNA-Binding Proteins Blotting Southern RNA Bacterial Open reading frame Genes Bacterial Plasmids Transcription Factors Research Article |
Zdroj: | Journal of Bacteriology. 175:7228-7235 |
ISSN: | 1098-5530 0021-9193 |
Popis: | To determine whether hemolytic factors other than the bifunctional hemolysin-adenylate cyclase toxin (cyclolysin) are expressed by Bordetella pertussis, a gene library was constructed from a virulent strain of B. pertussis, BP504, transformed into nonhemolytic Escherichia coli, and screened on blood agar plates. A strongly hemolytic colony which contained the plasmid pHLY1A was isolated. Nucleotide sequencing of pHLY1A revealed an open reading frame that could encode a 27-kDa protein. No similarity was detected between the deduced amino acid sequence of this open reading frame and those of any known bacterial cytolysins. However, significant homology was detected with FNR of E. coli and several other transcriptional regulators including HylX from Actinobacillus pleuropneumoniae, which can also confer a hemolytic phenotype on E. coli. An fnr mutant of E. coli, JRG1728, could be complemented by pHLY1A. Thus, the B. pertussis transcriptional regulator-like gene and the protein which it encoded were named btr and BTR, respectively. A BTR-deficient B. pertussis strain, BJB1, was constructed. The btr::kan mutation had no effect on the expression of hemolytic activity or on phase variation. Northern (RNA) blotting revealed that btr expression was not regulated by the BvgAS two-component sensor-regulator. On the basis of sequence similarity to FNR-like transcriptional regulators and the ability to complement an anaerobically deficient E. coli strain (JRG1728) in growing anaerobically, BTR may regulate B. pertussis gene expression in response to changes in oxygen levels or to changes in the redox potential of the bacterial environment. Its role in virulence remains to be determined. |
Databáze: | OpenAIRE |
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