title: Positive feedback regulation of stgR expression for secondary metabolism in Streptomyces coelicolor.
abstract: LysR-type transcriptional regulators (LTTRs) compose a large family and are responsible for various physiological functions in bacteria, while little is understood about their regulatory mechanism on secondary metabolism in Streptomyces. Here we reported that StgR, a typical LTTR in Streptomyces coelicolor, was a negative regulator of undecylprodigiosin (Red) and γ-actinorhodin (Act) production in the early developmental phase of secondary metabolism by suppressing the expression of two pathway-specific regulator genes, redD and actII-orf4, respectively. Meanwhile, stgR expression was downregulated during secondary metabolism to remove its repressive effects on antibiotic production. Moreover, stgR expression was positively autoregulated by direct binding of StgR to its own promoter (stgRp), and the binding site adjacent to translation start codon was determined by a DNase I footprinting assay. Furthermore, the StgR-stgRp interaction could be destroyed by the antibiotic γ-actinorhodin produced from S. coelicolor. Thus, our results suggested a positive feedback regulatory mechanism of stgR expression and antibiotic production for the rapid and irreversible development of secondary metabolism in Streptomyces.
authors: Zhejiang University, Institute of Biochemistry, College of Life Sciences, Hangzhou, China.
authors: Xu-Ming
authors: XM
authors: Mao
authors: Zhi-Hao
authors: ZH
authors: Sun
authors: Bi-Rong
authors: BR
authors: Liang
authors: Zhi-Bin
authors: ZB
authors: Wang
authors: Wei-Hong
authors: WH
authors: Feng
authors: Fang-Liang
authors: FL
authors: Huang
authors: Yong-Quan
authors: YQ
authors: Li
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D025461:Feedback, Physiological; D015964:Gene Expression Regulation, Bacterial; D019077:Helix-Turn-Helix Motifs; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D048372:Streptomyces coelicolor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D014157:Transcription Factors