Cloning and sequencing of a Haemophilus ducreyi fur homolog.
Iron regulation in a growing number of bacterial species is being attributed to the presence of a fur (ferric uptake regulation) regulatory system. In the presence of iron, Fur acts as a classical negative regulator, binding conserved sequences within the promoter of iron-repressible genes and blocking transcription. Western blot analysis utilizing Escherichia coli Fur antisera detected a band of approximately 17 kDa in soluble extracts of Haemophilus ducreyi. Additionally, Southern blot hybridization of the H. ducreyi chromosome with a meningococcal fur probe indicated that H. ducreyi might contain a fur homolog. This putative fur homolog was cloned into the E. coli vector pACYC184. This clone was capable of repressing expression of a normally Furregulated lacZ fusion in the fur-background of E. coli strain H1780. The deduced amino acid sequence shows H. ducreyi fur to be 54% identical and 73% similar to E. coli fur, containing putative DNA-binding and metal-binding domains. These data demonstrate that H. ducreyi has a functional fur system.
Carson
S D
SD
Department of Microbiology, University of North Carolina at Chapel Hill 27599, USA.
Thomas
C E
CE
Elkins
C
C
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D006191:Haemophilus ducreyi / Q000235:genetics* / Q000378:metabolism; D007501:Iron; D008969:Molecular Sequence Data; D012097:Repressor Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012097:Repressor Proteins; C068477:ferric uptake regulating proteins, bacterial; D007501:Iron