Open AccessMolecular analysis of the regulatory region of the Escherichia coli K-12 tyrB gene
Author(s) -
Jiyeon Yang,
J Pittard
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.169.10.4710-4715.1987
Subject(s) - biology , corepressor , regulon , gene , escherichia coli , plasmid , genetics , mutant , lac operon , operator (biology) , regulator gene , structural gene , primer extension , fusion gene , promoter , microbiology and biotechnology , regulation of gene expression , repressor , gene expression , rna
The tyrB gene from Escherichia coli K-12 was cloned and sequenced, and the transcriptional start point of tyrB was determined by primer extension. By using a fusion plasmid in which the lacZ structural gene is transcribed from the tyrB promoter, it was shown that the expression of tyrB is controlled at the transcriptional level by the TyrR protein, with tyrosine as corepressor. The fusion plasmid was used to isolate mutants in which the repression of tyrB had been abolished. The tyrB promoter-operator region of these mutants was sequenced, and the tyrB operator was identified. A comparison between the tyrB operator and those of the other genes belonging to the tyrR regulon is presented.