Analysis of a ferric uptake regulator (Fur) mutant of Desulfovibfio vulgatis hildenborough
Analysis of a ferric uptake regulator (Fur) mutant of Desulfovibfio vulgatis hildenborough
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DOI：
10.1128/aem.00276-07
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发表时间：
2007-09-01
影响因子：
4.4
通讯作者：
Wall, Judy D.
中科院分区：
文献类型：
--
作者：
Bender, Kelly S.;Yen, Huei-Che Bill;Wall, Judy D.
先前的实验研究了厌氧脱硫弧菌的转录谱，证明了Fur调节子在各种环境应激下的上调。为了检测Fur在D. vulgaris中，使用靶向诱变程序来缺失fur基因。由此产生的三角洲毛皮突变体（JW 707）的生长不受铁的可用性，但突变体没有表现出增加的敏感性，亚硝酸盐和渗透胁迫相比，温和型。JW 707的转录谱表明，铁结合的Fur充当亚铁吸收基因（feoAB）和在其启动子内含有预测的Fur结合位点的其他基因的传统阻遏物。尽管D.在普通人基因组中，编码TonB和TolQR的直系同源物的大的12基因操纵子也似乎被铁结合的Fur抑制。虽然预测参与铁稳态的其他基因不受Fur存在或不存在的影响，但观察到可解释为无铁Fur抑制或激活的替代表达模式。生理和转录数据都暗示了Fur在硫酸盐还原菌D中的全局调节作用。普通的
Previous experiments examining the transcriptional profile of the anaerobe Desulfovibrio vulgaris demonstrated up-regulation of the Fur regulon in response to various environmental stressors. To test the involvement of Fur in the growth response and transcriptional regulation of D. vulgaris, a targeted mutagenesis procedure was used for deleting the fur gene. Growth of the resulting Delta fur mutant (JW707) was not affected by iron availability, but the mutant did exhibit increased sensitivity to nitrite and osmotic stresses compared to the mild type. Transcriptional profiling of JW707 indicated that iron-bound Fur acts as a traditional repressor for ferrous iron uptake genes (feoAB) and other genes containing a predicted Fur binding site within their promoter. Despite the apparent lack of siderophore biosynthesis genes within the D. vulgaris genome, a large 12-gene operon encoding orthologs to TonB and TolQR also appeared to be repressed by iron-bound Fur. While other genes predicted to be involved in iron homeostasis were unaffected by the presence or absence of Fur, alternative expression patterns that could be interpreted as repression or activation by iron-free Fur were observed. Both the physiological and transcriptional data implicate a global regulatory role for Fur in the sulfate-reducing bacterium D. vulgaris.