@article{mbs:/content/journal/micro/10.1099/13500872-140-5-1059, author = "Virolle, Marie-Joelle and Gagnat, Josette", title = "Sequences involved in growth-phase-dependent expression and glucose repression of a Streptomyces α-amylase gene", journal= "Microbiology", year = "1994", volume = "140", number = "5", pages = "1059-1067", doi = "https://doi.org/10.1099/13500872-140-5-1059", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/13500872-140-5-1059", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "Streptomyces lividans", keywords = "glucose-repression", keywords = "α-amylase gene", keywords = "growth-phase-dependent expression", abstract = "In glycerol-grown, but not in glucose-grown cultures, expression in Streptomyces lividans TK24 of the cloned α-amylase gene (aml) of Streptomyces limosus is switched on toward the end of exponential growth. During this period, aml expression is further inducible by maltotriose. We showed that a 378 bp fragment, extending from position −204 through to + 174 (relative to the transcriptional start site), included cis-acting sequences involved in aml regulation. When this fragment was present on a multicopy plasmid, the growth-phase-dependent aml expression conferred by a DNA fragment cloned on a compatible low-copy-number plasmid was greatly enhanced, as if negative regulators were being titrated. A study of the regulation of aml expression in variants with deletions in the aml promoter region indicated that a direct repeat (DR) between positions −124 and −106 (relative to the transcriptional start site) and an inverted repeat (IR) between positions +9 and +24 were good candidates for secondary and primary operator sites, respectively. Deletion of a 29 bp fragment containing the IR rendered aml expression partly growth-phase-independent, resistant to glucose repression, and insensitive to maltotriose induction.", }