title: FliT acts as an anti-FlhD2C2 factor in the transcriptional control of the flagellar regulon in Salmonella enterica serovar typhimurium.
abstract: Flagellar operons are divided into three classes with respect to their transcriptional hierarchy in Salmonella enterica serovar Typhimurium. The class 1 gene products FlhD and FlhC act together in an FlhD(2)C(2) heterotetramer, which binds upstream of the class 2 promoters to facilitate binding of RNA polymerase. Class 2 expression is known to be enhanced by a disruption mutation in a flagellar gene, fliT. In this study, we purified FliT protein in a His-tagged form and showed that the protein prevented binding of FlhD(2)C(2) to the class 2 promoter and inhibited FlhD(2)C(2)-dependent transcription. Pull-down and far-Western blotting analyses revealed that the FliT protein was capable of binding to FlhD(2)C(2) and FlhC and not to FlhD alone. We conclude that FliT acts as an anti-FlhD(2)C(2) factor, which binds to FlhD(2)C(2) through interaction with the FlhC subunit and inhibits its binding to the class 2 promoter.
authors.affiliation: Department of Biology, Faculty of Science, Okayama University, Tsushima-Naka 3-1-1, Okayama 700-8530, Japan.
authors.forename: Shouji
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kutsukake
mesh_terms: D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D005407:Flagella / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D018832:Molecular Chaperones / Q000302:isolation & purification / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D018085:Regulon; D012486:Salmonella typhimurium / Q000235:genetics* / Q000378:metabolism; D015534:Trans-Activators / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D018832:Molecular Chaperones; D015534:Trans-Activators; C076735:fliT protein, Bacteria