Impact on Multiple Antibiotic Pathways Reveals MtrA as a Master Regulator of Antibiotic Production inStreptomycesspp. and Potentially in Other Actinobacteria

In natural environments, the ability to produce antibiotics helps the producing host to compete with surrounding microbes. InStreptomyces, increasing evidence suggests that the regulation of antibiotic production is complex, involving multiple regulatory factors. The regulatory factor MtrA is known to have additional roles beyond controlling development, and using bioassays, transcriptional studies, and DNA-binding assays, our study identified MtrA recognition sequences within multiple antibiotic pathways and indicated that MtrA directly controls the production of multiple antibiotics. Our analyses further suggest that this role of MtrA is evolutionarily conserved inStreptomycesspecies, as well as in other actinobacterial species, and also suggest that MtrA is a major regulatory factor in antibiotic production and in the survival of actinobacteria in nature.