Role of GntR Family Regulatory Gene in Gluconate Metabolism in M145.

Here we report functional characterization of the M145 gene which encodes a GntR-like regulator of the FadR subfamily. Bioinformatic analysis suggested that is part of putative operon involved in gluconate metabolism. Combining the results of knockout, transcriptional analysis of operon, 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 genes and . The knockout also influenced, in a medium-dependent manner, the production of secondary metabolites by . In comparison to the wild type, on gluconate-containing minimal medium, the mutant 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.