Rho-dependent transcription termination in the tryptophanase operon leader region of Escherichia coli K-12
نویسندگان
چکیده
منابع مشابه
Role of leader peptide synthesis in tryptophanase operon expression in Escherichia coli K-12.
We used site-directed mutagenesis to replace the Escherichia coli tryptophanase (tna) operon leader peptide start codon with AUC. This change greatly decreased the uninduced rate of tna operon expression, and it also lowered the response to inducer. We conclude that leader peptide synthesis plays an essential role in tna operon expression.
متن کاملEvidence for transcription antitermination control of tryptophanase operon expression in Escherichia coli K-12.
Tryptophanase, encoded by the gene tnaA, is a catabolic enzyme distinct from the enzymes of tryptophan biosynthesis. Tryptophanase synthesis is induced by tryptophan and is subject to catabolite repression. We studied the mechanism of tna operon induction. Mutants with altered rho factor were partially constitutive for tna expression, implicating rho-dependent transcription termination in the c...
متن کاملRho-dependent transcription termination in the tna operon of Escherichia coli: roles of the boxA sequence and the rut site.
Expression of the tryptophanase (tna) operon of Escherichia coli is regulated by catabolite repression and by tryptophan-induced transcription antitermination. Tryptophan induction prevents Rho-dependent transcription termination in the leader region of the operon. Induction requires translation of a 24-residue leader peptide-coding region, tnaC, containing a single, crucial Trp codon. Studies ...
متن کاملEvidence suggesting cis action by the TnaC leader peptide in regulating transcription attenuation in the tryptophanase operon of Escherichia coli.
Expression of the tryptophanase (tna) operon in Escherichia coli is regulated by catabolite repression and transcription attenuation. Elevated levels of tryptophan induce transcription antitermination at one or more Rho factor-dependent termination sites in the leader region of the operon. Induction requires translation of a 24-residue coding region, tnaC, located in the 319-nucleotide transcri...
متن کاملPoint mutations in the regulatory region of the ilvGMEDA operon of Escherichia coli K-12.
The ilvGMEDA operon of Escherichia coli K-12 is preceded by a regulatory region containing a promoter, a leader, and an attenuator. This region has been extensively characterized biochemically. In this note point mutations of the regulatory region are reported. The effect of these mutations on expression from the ilv regulatory region supports the previous biochemical analysis.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Bacteriology
سال: 1986
ISSN: 0021-9193,1098-5530
DOI: 10.1128/jb.166.1.217-223.1986