Identification of Streptomyces coelicolor genes involved in regulation of antibiotic synthesis.

To define genetic elements that regulate antibiotic synthesis, we screened for mutations that visibly blocked synthesis of Streptomyces coelicolor's two pigmented antibiotics and found mutant strains in which all four antibiotics were blocked. The responsible mutations defined two loci, absA and absB. Two additional approaches to defining genes have been taken: isolation of cloned genes with a dominant negative effect on antibiotic synthesis and isolation of genes which, in multicopy, can compensate for specific mutational blocks. These genes apparently function in a global regulatory pathway (or network) for control of antibiotic synthesis.