Pleiotropic roles of iron-responsive transcriptional regulator Fur in Burkholderia multivorans.
The fur (ferric uptake regulator) gene of Burkholderia multivorans ATCC 17616 was identified by transposon mutagenesis analysis. The fur deletion mutant of strain ATCC 17616 (i) constitutively produced siderophores, (ii) was more sensitive to reactive oxygen species (ROS) than the wild-type strain, (iii) showed lower superoxide dismutase and catalase activities than the wild-type strain, (iv) was unable to grow on M9 minimal agar plates containing several substrates that can be used as sole carbon sources by the wild-type strain, and (v) was hypersensitive to nitrite and nitric oxide under microaerobic and aerobic conditions, respectively. These results clearly indicate that the Fur protein in strain ATCC 17616 plays pleiotropic roles in iron homeostasis, removal and/or resistance to ROS and nitrosative stress, and energy metabolism. Furthermore, employment of an in vivo Fur titration assay system led to the isolation from the ATCC 17616 genome of 13 Fur-binding DNA regions, and a subsequent electrophoretic mobility-shift assay confirmed the direct binding of Fur protein to all of these DNA regions. Transcriptional analysis of the genes located just downstream of the Fur-binding sites demonstrated that Fur acts as a repressor for these genes. Nine of the 13 regions were presumed to be involved in the acquisition and utilization of iron.
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan.
Satoshi
S
Yuhara
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan.
Harunobu
H
Komatsu
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan.
Hiroyuki
H
Goto
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan.
Yoshiyuki
Y
Ohtsubo
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan.
Yuji
Y
Nagata
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan.
Masataka
M
Tsuda
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D019117:Burkholderia / Q000235:genetics* / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D003001:Cloning, Molecular; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D017672:Nitrogen Compounds / Q000494:pharmacology; D011485:Protein Binding; D017382:Reactive Oxygen Species / Q000494:pharmacology; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism*; D017384:Sequence Deletion
D001426:Bacterial Proteins; D017672:Nitrogen Compounds; D017382:Reactive Oxygen Species; D012097:Repressor Proteins; C068477:ferric uptake regulating proteins, bacterial; D002244:Carbon