title: FnrP interactions with the Pasteurella haemolytica leukotoxin promoter.
abstract: Pasteurella haemolytica FnrP is homologous to Fnr, the global transcriptional regulator of anaerobic respiration in Escherichia coli. To investigate the role of O(2) in the expression of P. haemolytica leukotoxin, we tested a lktC::lacZ fusion constructed in E. coli for a FnrP-mediated regulatory effect under aerobic and anaerobic growth conditions. Both E. coli Fnr and FnrP suppressed leukotoxin transcription under aerobic conditions. Under anaerobic conditions, Fnr suppressed transcription, while FnrP increased transcription. These results were confirmed using FnrP*, a mutant form of FnrP that activates anaerobically inducible genes under aerobic conditions. In mobility shift assays, partially purified FnrP bound to a potential regulatory site in a P. haemolytica lktC promoter fragment.
authors.affiliation: Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: G A
authors.initials: GA
authors.lastname: Uhlich
authors.forename: P J
authors.initials: PJ
authors.lastname: McNamara
authors.forename: J J
authors.initials: JJ
authors.lastname: Iandolo
authors.forename: D A
authors.initials: DA
authors.lastname: Mosier
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins; D005098:Exotoxins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D007506:Iron-Sulfur Proteins / Q000235:genetics* / Q000378:metabolism*; D007763:Lac Operon; D016978:Mannheimia haemolytica / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D005098:Exotoxins; C060704:FNR protein, E coli; D007506:Iron-Sulfur Proteins; D011993:Recombinant Fusion Proteins; C018579:leukotoxin; D004247:DNA; D010100:Oxygen