Integration host factor binds specifically to multiple sites in the ompB promoter of Escherichia coli and inhibits transcription.
Escherichia coli integration host factor (IHF) is a DNA-binding protein that participates in gene regulation, site-specific recombination, and other processes in E. coli and some of its bacteriophages and plasmids. In the present study, we showed that IHF is a direct negative effector of the ompB operon of E. coli. Gel retardation experiments and DNase I footprinting studies revealed that IHF binds to three sites in the ompB promoter region. In vitro transcription from ompB promoter fragments was specifically blocked by IHF. In vivo experiments showed that IHF is a negative effector of ompB expression in growing cells. Analysis of IHF binding site mutations strongly suggested that IHF binding in the ompB promoter region is necessary for the negative effects seen in vivo.
Tsui
P
P
Department of Biochemistry and Cell Biology, State University of New York, Stony Brook 11794-5212.
Huang
L
L
Freundlich
M
M
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000502:physiology*; D004926:Escherichia coli / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D034982:Integration Host Factors; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000235:genetics; D013997:Time Factors; D014158:Transcription, Genetic
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D034982:Integration Host Factors; D011993:Recombinant Fusion Proteins