Bacillus subtilis contains multiple Fur homologues:: identification of the iron uptake (Fur) and peroxide regulon (PerR) repressors
Bacillus subtilis contains multiple Fur homologues:: identification of the iron uptake (Fur) and peroxide regulon (PerR) repressors
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DOI：
10.1046/j.1365-2958.1998.00921.x
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发表时间：
1998-07-01
影响因子：
3.6
通讯作者：
Helmann, JD
中科院分区：
文献类型：
--
作者：
Bsat, N;Herbig, A;Helmann, JD
Fur（铁摄取调节蛋白）在许多革兰氏阴性菌中控制铁的摄取。尽管在革兰氏阳性菌中已鉴定出Fur同源物，但它们在基因调控中的作用尚不清楚。基因组测序揭示枯草芽孢杆菌中有三个Fur同源物：yqkL、yqfV和ygaG。我们证明yqkL编码一种铁摄取阻遏物：在yqkL突变体中，铁载体生物合成以及铁 - 铁载体摄取基因的转录都是组成型的。因此，yqkL编码一种在功能和结构上都与Fur相关的阻遏物。枯草芽孢杆菌的过氧化物应激基因可由过氧化氢或金属离子限制诱导。先前的遗传学研究确定了一个调控位点perR，推测其编码过氧化物调节子阻遏物。我们证明ygaG突变体具有perR表型：它对过氧化物具有高度抗性，并且过氧化氢酶、烷基过氧化氢还原酶和DNA结合蛋白MrgA过度表达。九个自发的perR突变体，由于它们在锰离子存在下能够去阻遏mrgA转录而被分离出来，所有这些突变体在ygaG位点都包含序列变化，并且可以通过克隆的ygaG基因进行互补。因此，ygaG编码过氧化物调节子阻遏物，并且与perR等位。
Fur (ferric uptake regulator) proteins control iron uptake in many Gram-negative bacteria. Although Fur homologues have been identified in Gram-positive bacteria, their roles in gene regulation are unknown. Genome sequencing has revealed three fur homologues in Bacillus subtilis: yqkL, yqfV and ygaG. We demonstrate that yqkL encodes an iron uptake repressor: both siderophore biosynthesis and transcription of ferri-siderophore uptake genes is constitutive in the yqkL mutant. Thus, yqkL encodes a repressor that is functionally as well as structurally related to Fur. B. subtilis peroxide stress genes are induced by either H2O2 or by metal ion limitation. Previous genetic studies defined a regulatory locus, perR, postulated to encode the peroxide regulon repressor. We demonstrate that a ygaG mutant has the perR phenotype: it is highly resistant to peroxides and overexpresses catalase, alkyl hydroperoxide reductase and the DNA binding protein MrgA. Nine spontaneous perR mutations, isolated by virtue of their ability to derepress mrgA transcription in the presence of manganous ion, all contain sequence changes in the ygaG locus and can be complemented by the cloned ygaG gene. Thus, ygaG encodes the peroxide regulon repressor and is allelic with perR.