Different proteins bind to the butyrolactone receptor protein ARE sequence located upstream of the regulatory ccaR gene of Streptomyces clavuligerus

摘要: Cell-free extracts from Streptomyces clavuligerus, purified by elution heparin-agarose with an ARE-containing DNA fragment or salt chromatography, bind to a 26 nt ARE sequence, for butyrolactone receptor proteins (ARE(ccaR)). This sequence is [corrected] located upstream of the ccaR gene, encoding activator protein CcaR required clavulanic acid and cephamycin C biosynthesis. The binding specific as shown competition 34 unlabelled probe identical sequence. A brp protein, was cloned S. clavuligerus. Sixty-one nucleotides another (ARE(brp)) found, suggesting that Brp autoregulates its expression. Pure recombinant rBrp binds specifically sequences present brp. brp-deleted mutant, clavuligerus Deltabrp::neo1, produced 150-300% 120-220% compared parental strain, exerts repressor role in antibiotic EMSA assays using affinity chromatography deletion mutant Deltabrp::neo1 lacked high-mobility band-shift due but still showed slow-mobility observed wild-type strain. These results indicate two different modulate biosynthesis action on gene