Regulation of rns, a positive regulatory factor for pili of enterotoxigenic Escherichia coli.
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.
Froehlich
B
B
Department of Microbiology and Immunology, Emory University, Atlanta, Georgia 30322.
Husmann
L
L
Caron
J
J
Scott
J R
JR
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
D017931:DNA Primers; D015534:Trans-Activators