Integration host factor is a negative effector of in vivo and in vitro expression of ompC in Escherichia coli.
Integration host factor (IHF) of Escherichia coli is a DNA-binding protein involved in gene expression and other cellular functions in E. coli and some of its bacteriophages and plasmids. We report here that IHF is a direct negative effector of the ompC operon of E. coli. IHF binds to ompC DNA and protects a region of 35 base pairs located upstream from the ompC promoters. The addition of IHF to a purified in vitro transcription system inhibited transcription from two of the three ompC promoters. In vivo experiments suggest that the in vitro results are physiologically relevant. IHF mutants show increased expression of OmpC. In addition, the OmpC- phenotype of certain strains is completely suppressed by a mutation in IHF.
Huang
L
L
Department of Biochemistry and Cell Biology, State University of New York, Stony Brook 11794-5215.
Tsui
P
P
Freundlich
M
M
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002462:Cell Membrane / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003850:Deoxyribonuclease I; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005838:Genotype; D034982:Integration Host Factors; D008969:Molecular Sequence Data; D009876:Operon; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014158:Transcription, Genetic
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D034982:Integration Host Factors; D003850:Deoxyribonuclease I