An iron-regulated outer-membrane protein specific to Bordetella bronchiseptica and homologous to ferric siderophore receptors
An iron-regulated outer-membrane protein specific to Bordetella bronchiseptica and homologous to ferric siderophore receptors
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DOI：
10.1099/00221287-143-1-135
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发表时间：
1997-01-01
期刊：
影响因子：
--
通讯作者：
Hoenes, T
中科院分区：
文献类型：
--
作者：
Beall, B;Hoenes, T
通过筛选铁抑制phoA的插入突变体文库，克隆了brontella bronchiseptica铁抑制外膜蛋白基因bfrA。bfrA基因编码了一个80 kDa的外膜蛋白，其氨基酸序列与属于tonb依赖性外膜受体家族的几种细菌蛋白高度一致。BfrA与大肠杆菌的Cir、霍乱弧菌的IrgA和三种已知的铁肠杆菌受体具有特异性。DNA杂交结果表明，bfrA在其他博德泰拉属中不存在。bfrA基因的表达是由一个低铁可用性启动子诱导的，该启动子与一个类似于共识的毛皮结合序列的序列重叠，bfrA基因的表达在一个bronchiseptica fur突变体中被抑制。在bfrA突变体中，对嗜铁杆菌碱性蛋白和外源性嗜铁杆菌肠杆菌素的利用不受影响。在试图寻找BfrA特异性的过程中，发现2,3-二羟基苯甲酰丝氨酸（DHBS）以bfeA（铁肠杆菌受体基因）依赖的方式被支气管杆菌和百日咳杆菌利用。此外，羟基酸铁载体铁铬和去铁胺B和铁源血红蛋白被证明独立于bfeA和bfrA在结核分枝杆菌和百日咳分枝杆菌中被利用。
The bfrA (Bordetella bronchiseptica ferric iron repressed outer-membrane protein) gene was cloned Bordetella bronchiseptica by screening a library of TnphoA insertion mutants for iron-repressed fusions to phoA. The bfrA gene encoded an 80 kDa outer-membrane protein with a high level of amino acid sequence identity to several bacterial proteins belonging to the family of Ton B-dependent outer-membrane receptors. BfrA was especially homologous to Cir of Escherichia coli, IrgA of Vibrio cholerae and to three previously characterized ferric enterobactin receptors. DNA hybridization results indicated that bfrA was not present in other Bordetella species. Expression of the bfrA gene was induced by low iron availability from a promoter overlapped by a sequence resembling a consensus Fur-binding sequence, and bfrA expression was derepressed in a B. bronchiseptica fur mutant. Utilization of the Bordetella siderophore alcaligin and the exogenous siderophore enterobactin was unaffected in bfrA mutants. Upon attempting to find the specificity of BfrA, 2,3-dihydroxybenzoylserine (DHBS) was shown to be utilized in a bfeA (Bordetella ferric enterobactin receptor gene)-dependent manner by B. bronchiseptica and B. pertussis. In addition, the hydroxamate siderophores ferrichrome and desferrioxamine B, and the iron source haemin were shown to be utilized independently of bfeA and bfrA in B. bronchiseptica and B. pertussis.