title: Characterization of FerC, a MarR-type transcriptional regulator, involved in transcriptional regulation of the ferulate catabolic operon in Sphingobium sp. strain SYK-6.
abstract: Sphingobium sp. strain SYK-6 is able to degrade various lignin-derived aromatic compounds including ferulate, vanillate, and syringate. In the SYK-6 cells, ferulate is converted to vanillin and acetyl-coenzyme A (acetyl-CoA) through the reactions catalyzed by feruloyl-CoA synthetase and feruloyl-CoA hydratase/lyase encoded by ferA and ferB, respectively. Here, we characterized the transcriptional regulation of ferBA controlled by a MarR-type transcriptional regulator, FerC. The ferC gene is located upstream of ferB. Reverse transcription (RT)-PCR analysis suggested that the ferBA genes form an operon. Quantitative RT-PCR analyses of SYK-6 and its mutant cells revealed that the transcription of the ferBA operon is negatively regulated by FerC, and feruloyl-CoA was identified as an inducer. The transcription start site of ferB was mapped at 30 nucleotides upstream from the ferB initiation codon. Purified His-tagged FerC bound to the ferC-ferB intergenic region. This region contains an inverted repeat sequence, which overlaps with a part of the -10 sequence and the transcriptional start site of ferB. The binding of FerC to the operator sequence was inhibited by the addition of feruloyl-CoA, indicating that FerC interacts with feruloyl-CoA as an effector molecule. Furthermore, hydroxycinnamoyl-CoAs, including p-coumaroyl-CoA, caffeoyl-CoA, and sinapoyl-CoA also acted as effector.
authors.affiliation: Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kasai
authors.forename: Naofumi
authors.initials: N
authors.lastname: Kamimura
authors.forename: Kenta
authors.initials: K
authors.lastname: Tani
authors.forename: Shusuke
authors.initials: S
authors.lastname: Umeda
authors.forename: Tomokuni
authors.initials: T
authors.lastname: Abe
authors.forename: Masao
authors.initials: M
authors.lastname: Fukuda
authors.forename: Eiji
authors.initials: E
authors.lastname: Masai
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D003373:Coumaric Acids / Q000378:metabolism*; D021901:DNA, Intergenic / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009876:Operon; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D042301:Sphingomonadaceae / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D003373:Coumaric Acids; D021901:DNA, Intergenic; D004268:DNA-Binding Proteins; D014157:Transcription Factors; C004999:ferulic acid