title: A TonB-dependent receptor regulates antifungal HSAF biosynthesis in Lysobacter.
abstract: Lysobacter species are Gram-negative bacteria that are emerging as new sources of antibiotics, including HSAF (Heat Stable Antifungal Factor), which was identified from L. enzymogenes with a new mode of action. LesR, a LuxR solo, was recently shown to regulate the HSAF biosynthesis via an unidentified mechanism in L. enzymogenes OH11. Here, we used a comparative proteomic approach to identify the LesR targets and found that LesR influenced the expression of 33 proteins belonging to 10 functional groups, with 9 proteins belonging to the TBDR (TonB-Dependent Receptor) family. The fundamental role of bacterial TBDR in nutrient uptake motivates us to explore their potential regulation on HSAF biosynthesis which is also modulated by nutrient condition. Six out of 9 TBDR coding genes were individually in-frame deleted. Phenotypic and gene-expression assays showed that TBDR7, whose level was lower in a strain overexpressing lesR, was involved in regulating HSAF yield. TBDR7 was not involved in the growth, but played a vital role in transcribing the key HSAF biosynthetic gene. Taken together, the current lesR-based proteomic study provides the first report that TBDR7 plays a key role in regulating antibiotic (HSAF) biosynthesis, a function which has never been found for TBDRs in bacteria.
authors.affiliation: College of Plant Protection (Key Laboratory of Integrated Management of Crop Diseases and Pests), Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Ruping
authors.initials: R
authors.lastname: Wang
authors.affiliation: College of Plant Protection (Key Laboratory of Integrated Management of Crop Diseases and Pests), Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Huiyong
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States.
authors.forename: Liangcheng
authors.initials: L
authors.lastname: Du
authors.affiliation: Institute of Biochemistry, and NCHU Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, ROC.
authors.forename: Shan-Ho
authors.initials: SH
authors.lastname: Chou
authors.affiliation: College of Plant Protection (Key Laboratory of Integrated Management of Crop Diseases and Pests), Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Liu
authors.affiliation: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China.
authors.forename: Youzhou
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China.
authors.forename: Fengquan
authors.initials: F
authors.lastname: Liu
authors.affiliation: College of Plant Protection (Key Laboratory of Integrated Management of Crop Diseases and Pests), Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Guoliang
authors.initials: G
authors.lastname: Qian
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D063990:Gene Ontology; D053528:Lysobacter / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D058977:Molecular Sequence Annotation; D040901:Proteomics; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D012097:Repressor Proteins; D015534:Trans-Activators; C057616:tonB protein, Bacteria; C064778:LuxR autoinducer binding proteins