Premium
Transcriptionai induction of Streptomyces cacaoi β‐lactamase by a β‐lactam compound
Author(s) -
Forsman M.,
Lindgren L.,
Haggström B.,
Jaurin B.
Publication year - 1989
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.1365-2958.1989.tb00125.x
Subject(s) - biology , gene , homology (biology) , nucleic acid sequence , streptomyces , streptomycetaceae , bacteria , genetics , microbiology and biotechnology , actinomycetales
Summary The soil bacterium Streptomyces cacaoi produces an extracellular β‐lactamase. The β‐lactamase expression could be induced by the β‐lactam compound 6‐amino penicillinoic acid (6‐APA). In liquid cultures, a 50‐fold increase in β‐lactamase expression was observed within the first three hours after addition of 6‐APA. Using the cloned β‐lactamase gene as a probe, it was shown that this increase was mediated at the level of transcriptional initiation. The start point of the induced β‐lactamase transcript was determined, and the nucleotide sequence of the promoter region was analysed. No noticeable homology was found to control regions of inducible β‐lactamase genes of other bacteria. A striking feature was the presence of six direct repeats (ten base pairs each) upstream of the promoter region. Thus, an example of an inducible regulatory gene system in this Gram‐positive microorganism is presented. Also, the primary structure of the β‐lactamase was deduced, showing a high degree of homology with class A β‐lactamases.