Fur in Magnetospirillum gryphiswaldense Influences Magnetosomes Formation and Directly Regulates the Genes Involved in Iron and Oxygen Metabolism

PLoS One

Ying Li¹  Jian Li¹  Jiangning Liu¹  Lei Qi²  Chengbo Rong²  WeiJia Zhang²  Longfei Wu² 

[1] France-China Biomineralization and Nano-structure Laboratory, Beijing, China;State Key Laboratory of Agro-biotechnology and College of Biological Sciences, China Agricultural University, Beijing, China

关键词: Regulator genes;    Gene regulation;    Chromatin immunoprecipitation;    Polymerase chain reaction;    Gene expression;    Iron;    Oxygen metabolism;    Mutant strains;   

DOI  :  10.1371/journal.pone.0029572

学科分类：医学（综合）

来源: Public Library of Science

【 摘 要 】

Magnetospirillum gryphiswaldense strain MSR-1 has the unique capability of taking up large amounts of iron and synthesizing magnetosomes (intracellular magnetic particles composed of Fe3O4). 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.

【 授权许可】

CC BY