title: Identification of Fur regulated genes in the bacterial fish pathogen Photobacterium damselae ssp. piscicida using the Fur titration assay.
abstract: Bacteria have developed a series of iron-scavenging and transport systems. The expression of many of the iron utilization genes is tightly regulated by the Fe2+ loaded Fur repressor protein. In this study, the Fur titration assay (FURTA) was used to screen for DNA fragments from a genomic DNA library of Photobacterium damselae ssp. piscicida containing potential Fe2+ Fur binding sites or iron binding-proteins which withdraw iron from Fur. One of the clones encoded a tonB gene and adjacent a functionally related exbB gene. An additional and complete tonB exbB exbD gene cluster was identified and sequenced. A gene homologous to the ferritin gene was found whose FURTA-positive phenotype may be explained by its iron-binding ability. Genes encoding a putative complete iron-regulated outer membrane transport protein and a pseudogene of a transport protein were found. The FURTA assay also revealed iron regulation of the AraC type transcriptional regulation.
authors.affiliation: Departamento de Microbioloxía e Parasitoloxía, Instituto de Acuicultura, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain. crosorio@usc.es
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Osorio
authors.forename: Manuel L
authors.initials: ML
authors.lastname: Lemos
authors.forename: Volkmar
authors.initials: V
authors.lastname: Braun
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D001692:Biological Transport; D004247:DNA / Q000378:metabolism; D005293:Ferritins / Q000378:metabolism; D005399:Fishes / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial; D015723:Gene Library; D007501:Iron / Q000737:chemistry / Q000378:metabolism; D007763:Lac Operon; D008954:Models, Biological; D008957:Models, Genetic; D008969:Molecular Sequence Data; D005810:Multigene Family; D016366:Open Reading Frames; D010641:Phenotype; D010776:Photobacterium / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012097:Repressor Proteins / Q000096:biosynthesis* / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; C068477:ferric uptake regulating proteins, bacterial; D004247:DNA; D005293:Ferritins; D007501:Iron