title: A molecular sensor that allows a gut commensal to control its nutrient foundation in a competitive ecosystem.
abstract: Little is known about how members of the indigenous microflora interact with their mammalian hosts to establish mutually beneficial relationships. We have used a gnotobiotic mouse model to show that Bacteroides thetaiotaomicron, a component of the intestinal microflora of mice and humans, uses a repressor, FucR, as a molecular sensor of L-fucose availability. FucR coordinates expression of an operon encoding enzymes in the L-fucose metabolic pathway with expression of another locus that regulates production of fucosylated glycans in intestinal enterocytes. Genetic and biochemical studies indicate that FucR does this by using fucose as an inducer at one locus and as a corepressor at the other locus. Coordinating this commensal's immediate nutritional requirements with production of a host-derived energy source is consistent with its need to enter and persist within a competitive ecosystem.
authors.affiliation: Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: L V
authors.initials: LV
authors.lastname: Hooper
authors.forename: J
authors.initials: J
authors.lastname: Xu
authors.forename: P G
authors.initials: PG
authors.lastname: Falk
authors.forename: T
authors.initials: T
authors.lastname: Midtvedt
authors.forename: J I
authors.initials: JI
authors.lastname: Gordon
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins; D001439:Bacteroides / Q000378:metabolism / Q000502:physiology*; D015374:Biosensing Techniques; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins; D005643:Fucose / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005856:Germ-Free Life; D007422:Intestines / Q000382:microbiology*; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D013050:Spectrometry, Fluorescence
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D005643:Fucose; D004247:DNA; D019747:Aldose-Ketose Isomerases; C019714:D-arabinose isomerase