Isolation and characterization of the nikR gene encoding a nickel-responsive regulator in Escherichia coli.
Expression of the nickel-specific transport system encoded by the Escherichia coli nikABCDE operon is repressed by a high concentration of nickel. By using random transposon Tn10 insertion, we isolated mutants in which expression of the nik operon became constitutive with respect to nickel. We have identified the corresponding nikR gene which encodes a nickel-responsive regulator. Expression of nikR was partially controlled by Fnr through transcription from the nikA promoter region. In addition, a specific transcription start site for the constitutive expression of nikR was found 51 bp upstream of the nikR gene.
De Pina
K
K
Laboratoire de Génétique Moléculaire des Microorganismes et des Interactions Cellulaires, CNRS UMR5577, Institut National des Sciences Appliquées, 69621 Villeurbanne Cedex, France.
Desjardin
V
V
Mandrand-Berthelot
M A
MA
Giordano
G
G
Wu
L F
LF
D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D007506:Iron-Sulfur Proteins / Q000378:metabolism; D016254:Mutagenesis, Insertional; D009532:Nickel / Q000494:pharmacology*; D009876:Operon; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012097:Repressor Proteins / Q000235:genetics; D015183:Restriction Mapping; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000096:biosynthesis
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D029968:Escherichia coli Proteins; C060704:FNR protein, E coli; D007506:Iron-Sulfur Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C068477:ferric uptake regulating proteins, bacterial; D009532:Nickel; D001616:beta-Galactosidase