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Sigma‐E is required for the production of the antibiotic actinomycin in Streptomyces antibioticus
Author(s) -
Jones George H.,
Paget Mark S. B.,
Chamberlin Leony,
Buttner Mark J.
Publication year - 1997
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 - 10.1046/j.1365-2958.1997.2001566.x
Subject(s) - dactinomycin , biology , mutant , streptomyces , biosynthesis , enzyme , atp synthase , streptomycetaceae , in vitro , promoter , gene , microbiology and biotechnology , biochemistry , rna , actinomycetales , gene expression , genetics , bacteria
The phsA gene encodes phenoxazinone synthase (PHS), which catalyses the penultimate step in the pathway for actinomycin biosynthesis in Streptomyces antibioticus . The phsA promoter strikingly resembles a putative Streptomyces σ E cognate promoter, and purified Eσ E holoenzyme transcribed the phsA promoter in vitro . However, the phsA promoter was still active in an S. antibioticus sigE null mutant and the level of PHS activity was unaffected. Despite this, disruption of sigE blocked actinomycin production completely. The loss of actinomycin production correlated with a 10‐fold decrease in the activity of actinomycin synthetase I, the enzyme which catalyses the activation of the precursor of the actinomycin chromophore.