AdpA is a regulatory protein of the AraC/XylS type which was first identified in 1993 as an activator of streptomycin production by Streptomyces griseus. Today streptomycete genomes are known to invariably harbor gene adpA, which is important for processes as diverse as replication and transcriptional control of genes for morphogenesis, antibiotic biosynthesis, and polymer decomposition to name just a few.