Characterization of a new ScbR-like γ-butyrolactone binding regulator (SlbR) in Streptomyces coelicolor

Abstract

γ-Butyrolactones in Streptomyces are well recognized as bacterial hormones, and they affect secondary metabolism of Streptomyces. γ-Butyrolactone receptors are considered important regulatory proteins, and various γ-butyrolactone synthases and receptors have been reported in Streptomyces. Here, we characterized a new regulator, SCO0608, that interacted with SCB1 (γ-butyrolactone of Streptomyces coelicolor) and bound to the scbR/A and adpA promoters. The SCO0608 protein sequences are not similar to those of any known γ-butyrolactone binding proteins in Streptomyces such as ScbR from S. coelicolor or ArpA from Streptomyces griseus. Interestingly, SCO0608 functions as a repressor of antibiotic biosynthesis and spore formation in R5 complex media. We showed the existence of another type of γ-butyrolactone receptor in Streptomyces, and this SCO0608 was named ScbR-like γ-butyrolactone binding regulator (SlbR) in S. coelicolor.

Molecular Regulation of Antibiotic Biosynthesis in Streptomyces

“…Moreover, in independent DNA affinity capture experiments done with S. coelicolor (169), a quite different protein, the SCO0608 protein (designated SlbR), was found to bind to both the adpA promoter and the scbA-scbR promoter and to be sensitive to SCBs even though it did not resemble any known gamma-butyrolactone-binding protein. Mutation of SCP0608 caused early production of ACT and RED on solid medium and hypersporulation (169). Few other streptomycetes have candidate SlbR orthologues, but proteins with moderate end-toend similarity are present in about half the species that have been subjected to genome sequencing.…”

NdgR, a Common Transcriptional Activator for Methionine and Leucine Biosynthesis in Streptomyces coelicolor

“…Other top-ranked proteins obtained from the metH probe are listed in Table S3 in the supplemental material. There are three characterized TFs (SCO0608-SlbR, SCO4118-AtrA, and SCO5231-GntR) (10,24,32) and one uncharacterized TF (SCO3198) in the list. A PEAKS Ϫ10lgP score of 100 was used as a cutoff.…”

Transcriptional Regulation of the Daptomycin Gene Cluster in Streptomyces roseosporus by an Autoregulator, AtrA

“…AdpA is one of the key pleiotropic transcriptional regulators in Streptomyces griseus, and is widely found in Streptomyces to control morphological development and secondary metabolism (10 -13). adpA is under the transcriptional control of a repressor (such as ArpA in S. griseus), which dissociates from the adpA promoter after binding to the growth phase-dependent ␥-butyrolactone molecules, thus causing derepression of adpA expression (11,14). Once activated, AdpA binds to the highly conserved binding elements (5Ј-TG-GCSNGWWY-3Ј) on the promoters of its regulons, which are involved in various cell developmental programs (11,15,16).…”