The Bradyrhizobium japonicum Fur protein is an iron-responsive regulator in vivo.
The Fur protein is a global regulator of iron metabolism in many bacterial species. However, Fur homologs from some rhizobia appear not to mediate iron-dependent gene expression in vivo. Here, transcriptional profiling analysis showed that more than one-fourth of the genes within the iron stimulon of Bradyrhizobium japonicum were aberrantly controlled by iron in a fur mutant. However, Fur has only a modest role in regulating iron transport genes. Quantitative real time reverse transcriptase PCR measurements confirmed abnormal gene expression in iron-limited cells of the fur strain, thereby demonstrating that Fur must function under those conditions. The findings show that B. japonicum Fur is involved in iron-dependent gene expression, and support the conclusion that rhizobial Fur proteins have novel functions compared with well studied model systems.
Yang
Jianhua
J
Department of Biochemistry, State University of New York at Buffalo, 140 Farber Hall, Buffalo, NY 14214, USA.
Sangwan
Indu
I
O'brian
Mark R
MR
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D015153:Blotting, Western; D020369:Bradyrhizobium; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D007501:Iron / Q000378:metabolism*; D046228:Microarray Analysis; D020411:Oligonucleotide Array Sequence Analysis; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D001426:Bacterial Proteins; D012097:Repressor Proteins; C068477:ferric uptake regulating proteins, bacterial; D007501:Iron