Premium
Repression of the aroF promoter by the TyrR repressor in Escherichia coli K‐12: role of the ‘upstream’ operator site
Author(s) -
Cobbett C. S.
Publication year - 1988
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1988.tb00042.x
Subject(s) - chloramphenicol acetyltransferase , biology , repressor , psychological repression , promoter , microbiology and biotechnology , operator (biology) , base pair , dna , gene , genetics , transcription factor , gene expression
Summary Three sequences are required for complete repression of the aroF promoter by the TyrR repressor protein. Two of these operator sites lie adjacent to each other and overlap the −35 region of the aroF promoter while the third lies about 70 base pairs upstream of the promoter. An aroF‐cat (chloramphenicol acetyltransferase) gene fusion has been used to assay the effect of DNA insertions that alter the distance between the two promoter‐proximal and the third, distal, operator sites on the repression of the aroF promoter in vivo. The distal site contributes to the repression of the promoter up to a distance of about 400 base pairs and its effect is not dependent on its separation from the first and second sites by an integral number of turns of the DNA helix.