Fur regulon of Salmonella typhimurium: identification of new iron-regulated genes.
In order to identify genes belonging to the Fur regulon of Salmonella typhimurium, a bank of 10,000 independent S. typhimurium MudJ insertion mutants was screened for lacZ fusions regulated by the iron response regulator Fur. In parallel, a plasmid gene bank of S. typhimurium consisting of 10,000 independent clones was screened for Fur-regulated promoters or iron binding proteins by the Fur titration assay (FURTA). Fur-regulated MudJ insertions and Fur-regulated promoters were mapped. In addition, iron-regulated promoter activities of transcriptional fusions from MudJ insertions and FURTA-positive clones were quantified. The nucleotide sequences of 11 FURTA-positive plasmids and of short fragments of DNA flanking three MudJ insertions were determined. By these methods we identified 14 Fur-regulated genes of S. typhimurium. For 11 of these genes, Fur-regulated homologs have been described in Escherichia coli or Yersinia enterocolitica, including fhuA,fhuB,fepA,fes,fepD,p43,entB,fur ,foxA,hemP, and fhuE. In addition, we identified three genes with homologs in other bacteria which have not previously been shown to be Fur regulated.
Tsolis
R M
RM
Department of Molecular Microbiology and Immunology, Oregon Health Sciences University, Portland 97201, USA.
Bäumler
A J
AJ
Stojiljkovic
I
I
Heffron
F
F
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002876:Chromosomes, Bacterial / Q000235:genetics; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D007501:Iron / Q000378:metabolism*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins; D018085:Regulon / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics*; D015183:Restriction Mapping; D012486:Salmonella typhimurium / Q000235:genetics*; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C068477:ferric uptake regulating proteins, bacterial; D007501:Iron