title: Effects of replacement of promoters and modification of the leader peptide region of the amy gene of Streptomyces griseus on synthesis and secretion of alpha-amylase by Streptomyces lividans.
abstract: Five different mutations were introduced into the leader peptide region of the alpha-amylase gene of Streptomyces griseus IMRU 3570. A mutation which increased the positive charge of the N-terminal region of the leader peptide enhanced the secretion of alpha-amylase by two- to threefold. Replacement of the native promoter of the amylase gene by the promoter of the Tn5 neo gene or by the promoter of the saf gene resulted in a 16-fold increase in alpha-amylase secretion. The enhanced secretion of alpha-amylase obtained by using the most efficient promoters was due to a correlated increase in the amount of transcript formed. The translation and secretion processes in S. lividans are not a bottleneck for enzyme secretion even at very high transcription rates, since stimulation of transcription of the alpha-amylase gene results in a proportionate increase in secretion of the enzyme.
authors.affiliation: Department of Ecology, Genetics and Microbiology, Faculty of Biology, University of León, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Vigal
authors.forename: J A
authors.initials: JA
authors.lastname: Gil
authors.forename: A
authors.initials: A
authors.lastname: Daza
authors.forename: M D
authors.initials: MD
authors.lastname: García-González
authors.forename: P
authors.initials: P
authors.lastname: Villadas
authors.forename: J F
authors.initials: JF
authors.lastname: Martín
mesh_terms: D000595:Amino Acid Sequence; D015870:Gene Expression / Q000235:genetics; D007700:Kinetics; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000235:genetics; D009154:Mutation / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D021382:Protein Sorting Signals / Q000737:chemistry / Q000235:genetics*; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics*; D013305:Streptomyces griseus / Q000201:enzymology / Q000235:genetics; D000516:alpha-Amylases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism
chemical_list: D021382:Protein Sorting Signals; D000516:alpha-Amylases