Yijun Huang, Weijia Zhang, Wei Jiang, Chengbo Rong, Ying Li
State Key Laboratories for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, 100094, China.
Biochemistry (Mosc). 2007 Nov;72(11):1247-53. doi: 10.1134/s0006297907110119.
In this study, a genomic library of Magnetospirillum gryphiswaldense MSR-1 strain was constructed and a fur-like gene (encoding Fur protein, ferric uptake regulator) was isolated and sequenced. This gene consisted of 420 bp and encoded 139 amino acid residues. To investigate the function of this gene in MSR-1, a fur mutant was generated by double crossover with a kanamycin cassette inserted into its coding region. Iron uptake and magnetosome formation were dramatically inhibited by disruption of fur. Iron content analysis of the fur mutant indicated that it contained approximately 0.037% by dry weight, which was at least 10-fold less than that observed in the wild type. Electron microscopy revealed the absence of a magnetosome in the fur mutant, although it was able to tolerate 1 mM H2O2 at 10-fold higher level than wild-type. These data suggest that Fur protein may possess a novel function in magnetic bacteria.
在本研究中，构建了嗜磁螺菌属格氏嗜铁珠菌MSR-1菌株的基因组文库，并分离和测序了一个类fur基因（编码Fur蛋白，铁摄取调节蛋白）。该基因由420个碱基对组成，编码139个氨基酸残基。为了研究该基因在MSR-1中的功能，通过双交换产生了一个fur突变体，其编码区插入了卡那霉素盒。fur的破坏显著抑制了铁摄取和磁小体形成。fur突变体的铁含量分析表明，其干重约含0.037%的铁，这比野生型中观察到的铁含量至少低10倍。电子显微镜显示fur突变体中没有磁小体，尽管它能够耐受比野生型高10倍的1 mM过氧化氢。这些数据表明，Fur蛋白可能在磁性细菌中具有新功能。
