Role of GntR Family Regulatory GeneSCO1678in Gluconate Metabolism inStreptomyces coelicolorM145

Here we report functional characterization of theStreptomyces coelicolorM145 geneSCO1678,which encodes a GntR-like regulator of the FadR subfamily. Bioinformatic analysis suggested thatSCO1678is part of putative operon(gnt)involved in gluconate metabolism. Combining the results ofSCO1678knockout, transcriptional analysis ofgntoperon, and Sco1678 protein-DNA electromobility shift assays, we established that Sco1678 protein controls the gluconate operon. It does so via repression of its transcription from a single promoter located between genesSCO1678andSCO1679. The knockout also influenced, in a medium-dependent manner, the production of secondary metabolites byS. coelicolor. In comparison to the wild type, on gluconate-containing minimal medium, theSCO1678mutant produced much less actinorhodin and accumulated a yellow-colored pigment, likely to be the cryptic polyketide coelimycin. Possible links between gluconate metabolism and antibiotic production are discussed.