Identification and characterization of transcriptional regulation of the Mannheimia haemolytica ferric uptake regulator.
The ferric uptake regulator (Fur) is an iron-dependent transcriptional regulator that regulates genes related to iron acquisition, oxidative stress response, and various other functions. Transcription of fur is typically self-regulating and sensitive to iron and oxidative stress. Following the identification of a fur gene in the genome of the bovine pathogen Mannheimia haemolytica, an attempt was made to characterize the transcriptional control of M. haemolytica fur. Northern blotting, RT-PCR, and primer extension were done to determine that M. haemolytica fur is transcribed using three distinct promoters, two of which are located within the upstream fldA gene. The third promoter is located upstream of a conserved hypothetical protein and drives transcription of a tricistronic message. Quantitative real time PCR experiments indicated that unlike current models of Fur regulation, M. haemolytica fur transcription is unchanged by iron depletion at logarithmic phase and repressed by iron depletion at stationary phase.
Gioia
Jason
J
Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA. jg126639@bcm.tmc.edu
Highlander
Sarah K
SK
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015152:Blotting, Northern / Q000379:methods / Q000662:veterinary; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000378:metabolism*; D000090463:Iron Deficiencies; D016978:Mannheimia haemolytica / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary; D013482:Superoxide Dismutase / Q000235:genetics; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000235:genetics
D001426:Bacterial Proteins; D012097:Repressor Proteins; C068477:ferric uptake regulating proteins, bacterial; D007501:Iron; D013482:Superoxide Dismutase; D001616:beta-Galactosidase