TY - JOUR
T1 - Cloning and characterization of btr, a Bordetella pertussis gene encoding an FNR-like transcriptional regulator
AU - Bannan, J. D.
AU - Moran, M. J.
AU - MacInnes, J. I.
AU - Soltes, G. A.
AU - Friedman, R. L.
PY - 1993
Y1 - 1993
N2 - 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 HlyX 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.
AB - 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 HlyX 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.
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U2 - 10.1128/jb.175.22.7228-7235.1993
DO - 10.1128/jb.175.22.7228-7235.1993
M3 - Article
C2 - 7693656
AN - SCOPUS:0027364448
SN - 0021-9193
VL - 175
SP - 7228
EP - 7235
JO - Journal of bacteriology
JF - Journal of bacteriology
IS - 22
ER -