Structure of the Escherichia coli K12 regulatory gene tyrR. Nucleotide sequence and sites of initiation of transcription and translation.

The nucleotide sequence of 1964 base pairs of the Escherichia coli K12 chromosome containing the autogenously regulated regulatory gene tyrR has been determined. The site of initiation of transcription of tyrR has been mapped by primer-extension analysis, and the initiation codon has been identified by site-specific deletion mutagenesis. The nucleotide sequence predicts a subunit molecular weight of 53,099 for the TyrR protein. Codon usage in the tyrR structural gene shows a bias toward those synonymic codons which are used rarely in efficiently expressed E. coli genes. The nucleotide sequence of a 22-base pair region adjacent to the promoter and distal to the structural gene exhibits considerable identity with corresponding regions of other genes regulated by tyrR. It is proposed that this is a site for repression by the TyrR protein.