Transcription initiation at the tryptophanase promoter of Escherichia coli K-12
نویسندگان
چکیده
منابع مشابه
Evidence 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 کاملInternal promoter in the ilvGEDA transcription unit of Escherichia coli K-12.
Segments of the ilvGEDA transcription unit have been cloned into the promoter tester plasmid pMC81. This vector contains cloning sites situated upstream of the lacZ gene coding for beta-galactosidase. Using this method we have quantitatively evaluated in vivo (i) the activity of previously described promoter, pG, preceding ilvG; (ii) the relative activity of pE promoter, previously postulated t...
متن کاملNucleotide sequence of the structural gene for tryptophanase of Escherichia coli K-12.
The tryptophanase structural gene, tnaA, of Escherichia coli K-12 was cloned and sequenced. The size, amino acid composition, and sequence of the protein predicted from the nucleotide sequence agree with protein structure data previously acquired by others for the tryptophanase of E. coli B. Physiological data indicated that the region controlling expression of tnaA was present in the cloned se...
متن کاملRole 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 کاملRegulation of galactose operon at the gal operator-promoter region in Escherichia coli K-12.
The capR (lon) product controls expression of the gal operon independently of the galR repressor. Previously, mutations of the gal operon have been isolated that are semiconstitutive and alter response to the capR and/or capT product. Such mutants imply the existence of a distinct site in the operon that responds to capR (capT) control. This mutation could be either in a site near the operator-...
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: 1982
ISSN: 0021-9193,1098-5530
DOI: 10.1128/jb.151.2.942-951.1982