title: Differential signal transduction via TrmB, a sugar sensing transcriptional repressor of Pyrococcus furiosus.
abstract: TrmB is a transcriptional repressor of the hyperthermophilic archaeon Pyrococcus furiosus serving at least two operons. TrmB represses genes encoding an ABC transporter for trehalose and maltose (the TM system) with trehalose and maltose as inducers. TrmB also represses genes encoding another ABC transporter for maltodextrins (the MD system) with maltotriose and sucrose as inducers. Here we report that glucose which was also bound by TrmB acted as a corepressor (causing stronger repression) for both the TM and the MD system. Binding of glucose by TrmB was increased in the presence of TM promoter DNA. Maltose which acted as inducer for the TM system acted as a corepressor for the MD system intensifying repression. We propose that the differential conformational changes of TrmB in response to binding the different sugars governs the ability of TrmB to interact with the promoter region and represents a simple mechanism for selecting the usage of one carbon source over the other, reminiscent of catabolite repression in bacteria.
authors.affiliation: Department of Biology, University of Konstanz, 78457 Konstanz, Germany.
authors.forename: Sung-Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Melanie
authors.initials: M
authors.lastname: Surma
authors.forename: Sabine
authors.initials: S
authors.lastname: Seitz
authors.forename: Winfried
authors.initials: W
authors.lastname: Hausner
authors.forename: Michael
authors.initials: M
authors.lastname: Thomm
authors.forename: Winfried
authors.initials: W
authors.lastname: Boos
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019848:Gene Expression Regulation, Archaeal; D005947:Glucose / Q000378:metabolism*; D008320:Maltose / Q000378:metabolism; D009876:Operon; D011401:Promoter Regions, Genetic; D011487:Protein Conformation; D020027:Pyrococcus furiosus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014199:Trehalose / Q000378:metabolism; D014312:Trisaccharides / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; D019843:Archaeal Proteins; D012097:Repressor Proteins; D014312:Trisaccharides; C008317:maltotriose; D008320:Maltose; D014199:Trehalose; D005947:Glucose