Open AccessMolecular analysis of the TyrR protein-mediated activation of mtr gene expression in Escherichia coli K-12
Author(s) -
Joseph P. Sarsero,
A. J. Pittard
Publication year - 1991
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.173.23.7701-7704.1991
Subject(s) - biology , escherichia coli , gene , tyrosine , promoter , gene expression , microbiology and biotechnology , binding site , biochemistry , genetics
Expression of the mtr gene, which encodes a tryptophan-specific transport system in Escherichia coli K-12, is activated by the TyrR protein. Two TyrR protein binding sites (TYR R boxes) are positioned upstream of the -35 promoter region. Mutational and DNase protection studies indicate that TyrR protein binds preferentially to the TYR R box closest to the promoter, and this is essential for activation of gene expression. In the presence of tyrosine and ATP, a second TyrR molecule is able to cooperatively bind to the second box and cause a further increase in the level of activation.