Open AccessNew regulatory features of the promoters of an Escherichia coli rRNA gene
Author(s) -
Tamás Lukácsovich,
Imre Boros,
Pál Venetianer
Publication year - 1987
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.169.1.272-277.1987
Subject(s) - promoter , biology , plasmid , escherichia coli , gene , coding region , transcription (linguistics) , genetics , microbiology and biotechnology , dna , gene expression , linguistics , philosophy
Recombinant plasmids were constructed by fusing either promoter p1 or p2 or both promoters of the rrnB gene of Escherichia coli to a DNA fragment coding for the N-terminal alpha-peptide of beta-galactosidase. These plasmids contained various lengths of the 5'-leader region of rRNA as the 5'-terminal end of the alpha-peptide messenger. In some cases the entire 5'-terminal rRNA-coding sequence was removed, and alpha-peptide synthesis was governed by rac promoters formed by fusion of rrnBp2 and lac promoters. By measuring the level of alpha peptide, conclusions could be drawn about the activities of the promoters under various physiological conditions. It was found that the rate of transcription starting from promoter p1 or p2 might vary more than 10-fold during the growth cycle, showing a sharp maximum during outgrowth from the stationary phase into exponential growth or during nutritional shift-up. The target sequence of this regulation was localized to the leader region of the rrnB gene.