title: Analysis of a ferric uptake regulator (Fur) mutant of Desulfovibrio vulgaris Hildenborough.
abstract: Previous experiments examining the transcriptional profile of the anaerobe Desulfovibrio vulgaris demonstrated up-regulation of the Fur regulon in response to various environmental stressors. To test the involvement of Fur in the growth response and transcriptional regulation of D. vulgaris, a targeted mutagenesis procedure was used for deleting the fur gene. Growth of the resulting Deltafur mutant (JW707) was not affected by iron availability, but the mutant did exhibit increased sensitivity to nitrite and osmotic stresses compared to the wild type. Transcriptional profiling of JW707 indicated that iron-bound Fur acts as a traditional repressor for ferrous iron uptake genes (feoAB) and other genes containing a predicted Fur binding site within their promoter. Despite the apparent lack of siderophore biosynthesis genes within the D. vulgaris genome, a large 12-gene operon encoding orthologs to TonB and TolQR also appeared to be repressed by iron-bound Fur. While other genes predicted to be involved in iron homeostasis were unaffected by the presence or absence of Fur, alternative expression patterns that could be interpreted as repression or activation by iron-free Fur were observed. Both the physiological and transcriptional data implicate a global regulatory role for Fur in the sulfate-reducing bacterium D. vulgaris.
authors.affiliation: Department of Biochemistry, 117 Schweitzer Hall, Columbia, MO 65211, USA.
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Bender
authors.forename: Huei-Che Bill
authors.initials: HC
authors.lastname: Yen
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Hemme
authors.forename: Zamin
authors.initials: Z
authors.lastname: Yang
authors.forename: Zhili
authors.initials: Z
authors.lastname: He
authors.forename: Qiang
authors.initials: Q
authors.lastname: He
authors.forename: Jizhong
authors.initials: J
authors.lastname: Zhou
authors.forename: Katherine H
authors.initials: KH
authors.lastname: Huang
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Alm
authors.forename: Terry C
authors.initials: TC
authors.lastname: Hazen
authors.forename: Adam P
authors.initials: AP
authors.lastname: Arkin
authors.forename: Judy D
authors.initials: JD
authors.lastname: Wall
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003901:Desulfovibrio / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000378:metabolism; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000235:genetics*; D013431:Sulfates / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; D013431:Sulfates; C068477:ferric uptake regulating proteins, bacterial; D007501:Iron