Functional analysis of SGR4635-induced enhancement of pigmented antibiotic production in Streptomyces lividans.

The Gram-positive mycelium-producing bacterium Streptomyces undergoes complex morphological differentiation after autolytic degradation of the vegetative mycelium. Cell-wall breakdown during growth stimulates cell development and secondary metabolite production by Streptomyces. N-acetylglucosamine (GlcNAc) produced by cell-wall lysis acts as a signal molecule, triggering the production of secondary metabolites in S. coelicolor A3(2). Here, we report that introduction of multiple copies of the GlcNAc-internalizing gene (sgr4635, encoding nagE2) of S. griseus activates actinorhodin and undecylprodigiosin production during the late growth of S. lividans in the absence of GlcNAc. Furthermore, the repressor-type transcriptional regulator DasR binds to two operator sites upstream of sgr4635. Our findings indicate that sgr4635 induces DasR-mediated antibiotic production by internalizing the GlcNAc accumulated from cell-wall lysis.