title: JadR and jadR2 act synergistically to repress jadomycin biosynthesis.
abstract: The biosynthesis of antibiotics is controlled by cascade regulation involving cluster-situated regulators (CSRs) and pleiotropic regulators. Three CSRs have been identified in the jadomycin biosynthetic gene cluster, including one OmpR-type activator (JadR1) and two TetR-like repressors (JadR and JadR2). To examine their interactions in jadomycin biosynthesis, a series of mutants were generated and tested for jadomycin production. We noticed that jadomycin production in the jadR-jadR2 double mutant was increased dramatically compared with either single mutant. Transcriptional analysis showed that jadR and jadR2 act synergistically to repress jadomycin production by inhibiting the transcription of jadR1. Furthermore, jadR and jadR2 reciprocally inhibit each other. The complex interactions among these three CSRs may provide clues for the activation of the jadomycin gene cluster, which would otherwise remain silent without stimulation from stress signals.
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhengzhong
authors.initials: Z
authors.lastname: Zou
authors.forename: Guoqing
authors.initials: G
authors.lastname: Niu
authors.forename: Huarong
authors.initials: H
authors.lastname: Tan
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D017931:DNA Primers / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D007546:Isoquinolines / Q000737:chemistry*; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D016366:Open Reading Frames; D060888:Real-Time Polymerase Chain Reaction; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*; D017422:Sequence Analysis, DNA; D013302:Streptomyces / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D007546:Isoquinolines; C096440:JadR2 protein, Streptomyces venezuelae; D012097:Repressor Proteins; C081750:jadomycin B