Effects of mutations in the Pseudomonas putida miaA gene: Regulation of the trpE and trpGDC operons in P-putida by attenuation

Tn5 insertion mutants defective in regulation of the Pseudomonas putida trp E and trpGDC operons by tryptophan were found to contain insertions in the P. putida mia 4 gene, whose product (in Escherichia coli) modifies tRNA(Trp ) and is required for attenuation. Nucleotide sequences upstream of trpE an d trpG encode putative leader peptides similar in sequence to leader peptid es found in other bacterial species, and the phenotypes of the mutants stro ngly suggest Chat transcription of these operons is regulated solely by att enuation.