Molecular analysis of the TyrR protein-mediated activation of mtr gene expression in Escherichia coli K-12.
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.
Department of Microbiology, University of Melbourne, Parkville, Victoria, Australia.
J P
JP
Sarsero
A J
AJ
Pittard
D000595:Amino Acid Sequence; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010957:Plasmids; D011994:Recombinant Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014364:Tryptophan / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C069256:TyrR protein, E coli; D014443:Tyrosine; D014364:Tryptophan; D001616:beta-Galactosidase