Integration host factor is a transcriptional cofactor of pilE in Neisseria gonorrhoeae.
Integration host factor (IHF) is a small, heterodimeric DNA-binding protein with pleiotropic function. IHF was purified to apparent homogeneity from Neisseria gonorrhoeae. Gel-retardation assays demonstrated binding of IHF to the pilE promoter region. The IHF-binding site was identified by DNase I protection assays and mapped proximal to three previously defined pilE promoters. Removal of the putative IHF-binding domain from pilE promoter DNA negated retardation of the DNA fragment when assessed by gel-shift analysis. Kleinschmidt electron microscopy showed pronounced kinking of pilE promoter DNA following incubation with IHF. Isogenic N. gonorrhoeae strains were constructed that contained either a wild-type pilE locus or a deleted pilE locus where the IHF-binding domain was removed. Primer-extension analysis and Northern blotting of total gonococcal RNA showed that in the absence of IHF binding at the pilE promoter, transcription was reduced 10-fold. Together, these data indicate that IHF is a transcriptional co-activator of pilE.
Hill
S A
SA
Laboratory of Microbial Structure and Function, National Institutes of Health, National Institutes of Allergy and Infectious Diseases, Rocky Mountain Laboratories, Hamilton, Montana 59840, USA. Stuart_Hill@nih.gov
Samuels
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Carlson
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Wilson
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Hogan
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Lubke
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Belland
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RJ
D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002874:Chromosome Mapping; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D036781:Fimbriae Proteins; D005798:Genes, Bacterial; D034982:Integration Host Factors; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008854:Microscopy, Electron; D008954:Models, Biological; D008969:Molecular Sequence Data; D009344:Neisseria gonorrhoeae / Q000235:genetics / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D034982:Integration Host Factors; D008562:Membrane Glycoproteins; C074063:pilE protein, Neisseria gonorrhoeae; D036781:Fimbriae Proteins