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Cloning, characterization and regulation of an α‐amylase gene from Streptomyces limosus
Author(s) -
Virolle M.J.,
Bibb M. J.
Publication year - 1988
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1988.tb00021.x
Subject(s) - streptomyces coelicolor , biology , microbiology and biotechnology , gene , gene expression , streptomyces , psychological repression , regulation of gene expression , biochemistry , genetics , mutant , bacteria
Summary An α‐amylase gene ( aml ) of Streptomyces limosus ATCC 19778 was cloned in Streptomyces lividans 66. S 1 mapping experiments identified an aml transcript 1.8 kb in length and the extracellular enzyme was estimated to be 59 kD in size, suggesting that aml was transcribed as a monocistronic mRNA species. Expression of the gene was induced by maltose (or maltodextrins) in S. Iimosus and when aml was cloned in S. lividans or Streptomyces coelicolor A3(2). In S. Iimosus , mannitol repressed aml expression while glucose had little or no effect; in S. lividans and S. coelicolor the relative effects of the two sugars were reversed. Both induction and carbon‐source repression of aml expression appeared to occur at the level of transcriptional initiation. Glucose repression in S. coelicolor was dependent upon a functional glucose kinase gene.