title: Regulation of rns, a positive regulatory factor for pili of enterotoxigenic Escherichia coli.
abstract: Attachment of enterotoxigenic Escherichia coli to the human gut is considered an important early step in infection that leads to diarrhea. This attachment is mediated by pili, which belong to a limited number of serologically distinguishable types. Many of these pili require the product of rns, or a closely related gene, for their expression. We have located the major promoter for rns and found that although its sequence diverges significantly from a sigma-70 promoter consensus sequence, it is very strong. Transcription of rns is negatively regulated both at a region upstream of this promoter and at a region internal to the rns open reading frame. In addition, rns positively regulates its own transcription, probably by counteracting these two negative effects.
authors.affiliation: Department of Microbiology and Immunology, Emory University, Atlanta, Georgia 30322.
authors.forename: B
authors.initials: B
authors.lastname: Froehlich
authors.forename: L
authors.initials: L
authors.lastname: Husmann
authors.forename: J
authors.initials: J
authors.lastname: Caron
authors.forename: J R
authors.initials: JR
authors.lastname: Scott
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D016384:Consensus Sequence; D017931:DNA Primers; D003967:Diarrhea / Q000382:microbiology; D004926:Escherichia coli / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D010861:Fimbriae, Bacterial / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005809:Genes, Regulator; D006801:Humans; D007422:Intestines / Q000382:microbiology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D015534:Trans-Activators / Q000096:biosynthesis; D014158:Transcription, Genetic
chemical_list: D017931:DNA Primers; D015534:Trans-Activators