S‐adenosylmethionine activates adpA transcription and promotes streptomycin biosynthesis in Streptomyces griseus

Abstract S‐adenosylmethionine (SAM), the major methyl donor in diverse biological processes, was previously documented as a regulator for secondary metabolism in Streptomyces. The present study demonstrates that exogenous SAM, in a quantity as low as 10 μM, enhanced streptomycin production and adpA transcription in both Streptomyces griseus wild‐type strain and mutant HO1, which displays no ArpA repression on the adpA promoter. SAM also enhanced xylE expression driven by the promoter of adpA or strR in a heterologous host, S. lividans. This report substantiates that exogenous SAM promotes adpA transcription in S. griseus, which is involved in the SAM‐mediated promotion of streptomycin, and that the mechanism underlying this event is shared in S. lividans.