title: PTS regulation domain-containing transcriptional activator CelR and sigma factor σ(54) control cellobiose utilization in Clostridium acetobutylicum.
abstract: The phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) regulation domain (PRD)-containing enhancer binding proteins (EBPs) are an important class of σ(54) -interacting transcriptional activators. Although PRD-containing EBPs are present in many Firmicutes, most of their regulatory functions remain unclear. In this study, the transcriptional regulons of about 50 PRD-containing EBPs in diverse Firmicutes species are reconstructed by using a comparative genomic approach, which contain the genes associated with utilization of β-glucosides, fructose/levan, mannose/glucose, pentitols, and glucosamine/fructosamine. We then present experimental evidence that the cel operon involved in cellobiose utilization is directly regulated by CelR and σ(54) (SigL) in Clostridium acetobutylicum. The predicted three CelR-binding sites and σ(54) promoter elements upstream of the cel operon are verified by in vitro binding assays. We show that CelR has an ATPase activity, which is strongly stimulated by the presence of DNA containing the CelR-binding sites. Moreover, mutations in any one of the three CelR-binding sites significantly decreased the cel promoter activity probably due to the need for all three DNA sites for maximal ATPase activity of CelR. It is suggested that CelR is regulated by PTS-mediated phosphorylation at His-551 and His-829, which exerts a positive effect and an inhibitory effect, respectively, on the CelR activity.
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Xiaoqun
authors.initials: X
authors.lastname: Nie
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gu
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Yang
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Yang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D001665:Binding Sites; D002475:Cellobiose / Q000378:metabolism*; D046969:Clostridium acetobutylicum / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D009876:Operon; D010728:Phosphoenolpyruvate / Q000378:metabolism; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism; D011401:Promoter Regions, Genetic; D051877:RNA Polymerase Sigma 54 / Q000235:genetics / Q000378:metabolism*; D018085:Regulon; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; C119069:CelR protein, bacteria; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D002475:Cellobiose; D010728:Phosphoenolpyruvate; D010770:Phosphotransferases; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; D051877:RNA Polymerase Sigma 54