title: Fur in Magnetospirillum gryphiswaldense influences magnetosomes formation and directly regulates the genes involved in iron and oxygen metabolism.
abstract: Magnetospirillum gryphiswaldense strain MSR-1 has the unique capability of taking up large amounts of iron and synthesizing magnetosomes (intracellular magnetic particles composed of Fe(3)O(4)). The unusual high iron content of MSR-1 makes it a useful model for studying biological mechanisms of iron uptake and homeostasis. The ferric uptake regulator (Fur) protein plays a key role in maintaining iron homeostasis in many bacteria. We identified and characterized a fur-homologous gene (MGR_1314) in MSR-1. MGR_1314 was able to complement a fur mutant of E. coli in iron-responsive manner in vivo. We constructed a fur mutant strain of MSR-1. In comparison to wild-type MSR-1, the mutant strain had lower magnetosome formation, and was more sensitive to hydrogen peroxide and streptonigrin, indicating higher intracellular free iron content. Quantitative real-time RT-PCR and chromatin immunoprecipitation analyses indicated that Fur protein directly regulates expression of several key genes involved in iron transport and oxygen metabolism, in addition it also functions in magnetosome formation in M. gryphiswaldense.
authors.affiliation: State Key Laboratory of Agro-biotechnology and College of Biological Sciences, China Agricultural University, Beijing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Qi
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: WeiJia
authors.initials: W
authors.lastname: Zhang
authors.forename: Jiangning
authors.initials: J
authors.lastname: Liu
authors.forename: Chengbo
authors.initials: C
authors.lastname: Rong
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Longfei
authors.initials: L
authors.lastname: Wu
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000502:physiology*; D006861:Hydrogen Peroxide / Q000633:toxicity; D007501:Iron / Q000378:metabolism*; D055944:Magnetosomes / Q000235:genetics / Q000378:metabolism*; D042201:Magnetospirillum / Q000235:genetics* / Q000378:metabolism*; D053858:Metabolic Networks and Pathways / Q000235:genetics; D010100:Oxygen / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; C068477:ferric uptake regulating proteins, bacterial; D006861:Hydrogen Peroxide; D007501:Iron; D010100:Oxygen