title: Enhancement of transcriptional activity of the Escherichia coli trp promoter by upstream A + T-rich regions.
abstract: The Escherichia coli trp promoter has two A + T-rich blocks in the upstream region. The deletion of the segments containing these blocks resulted in a decrease in promoter strength. By replacing the upstream region of trp promoter with one or two large A + T-rich blocks of the major leftward lambda promoter (pL), modified trp promoters (designated let) were constructed, and the transcriptional activities of these promoters towards the expression of the human interferon-gamma gene were measured. The let promoters which contain one (designated letI) or two (designated letII) A + T-rich blocks were about 6 times (at the levels of interferon activity produced) or about 3 times (at the levels of mRNA synthesized de novo) stronger than the wild-type trp promoter. The transcription from the letI promoter was controlled both by the trpR-coded repressor and the cI-coded repressor of phage lambda.
mesh_terms: D000225:Adenine; D001482:Base Composition; D001483:Base Sequence; D004742:Enhancer Elements, Genetic; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics*; D005809:Genes, Regulator; D010957:Plasmids; D011401:Promoter Regions, Genetic; D013941:Thymine; D014158:Transcription, Genetic; D014364:Tryptophan / Q000096:biosynthesis / Q000494:pharmacology
chemical_list: D014364:Tryptophan; D000225:Adenine; D013941:Thymine