FpvB, an alternative type I ferripyoverdine receptor of Pseudomonas aeruginosa
FpvB, an alternative type I ferripyoverdine receptor of Pseudomonas aeruginosa
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DOI：
10.1099/mic.0.27035-0
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发表时间：
2004-06-01
期刊：
影响因子：
2.8
通讯作者：
Cornelis, P
中科院分区：
文献类型：
--
作者：
Ghysels, B;Dieu, BTM;Cornelis, P
在铁限制的条件下，铜绿假单胞菌分泌高亲和力的铁载体绿脓菌荧光素，以在细胞外环境中吸收Fe（III）并将其穿梭到细胞中。绿脓菌荧光素-Fe（III）复合物的摄取由特异性外膜受体蛋白FpvA（铁绿脓菌荧光素受体）介导。可以区分三种铜绿假单胞菌铁粒异形体，每种产生不同的绿脓菌荧光素（I-III型）和同源FpvA受体。铜绿假单胞菌PAO 1（I型）的fpvA突变体在铁限制条件下的生长仍然可以被其同源绿脓菌荧光素刺激，表明I型铁绿脓菌荧光素存在替代摄取途径。对PAO 1基因组的计算机分析显示，基因PA 4168的产物与FpvA具有高度的相似性。在fpvA突变体中PA 4168（称为fpvB）的失活完全消除了利用I型绿脓菌荧光素的能力。在酪蛋白氨基酸（CAA）和M9-葡萄糖培养基中，fpvB的表达受铁限制的诱导，但与fpvA不同，在含有甘油作为碳源的复杂发酵培养基中，fpvB的表达不受铁限制的诱导。在其他铜绿假单胞菌分离株中也检测到fpvB基因，包括产生II型和III型绿脓菌荧光素的菌株。这些菌株中fpvB同源物的失活损害了它们利用I型ferripyoverdine作为铁源的能力。因此，反式fpvB的引入恢复了利用I型铁绿荧光素的能力。
Under conditions of iron limitation, Pseudomonas aeruginosa secretes a high-affinity siderophore pyoverdine to scavenge Fe(III) in the extracellular environment and shuttle it into the cell. Uptake of the pyoverdine-Fe(III) complex is mediated by a specific outer-membrane receptor protein, FpvA (ferripyoverdine receptor). Three P. aeruginosa siderovars can be distinguished, each producing a different pyoverdine (type I-III) and a cognate FpvA receptor. Growth of an fpvA mutant of P. aeruginosa PAO1 (type I) under iron-limiting conditions can still be stimulated by its cognate pyoverdine, suggesting the presence of an alternative uptake route for type I ferripyoverdine. In silico analysis of the PAO1 genome revealed that the product of gene PA4168 has a high similarity with FpvA. Inactivation of PA4168 (termed fpvB) in an fpvA mutant totally abolished the capacity to utilize type I pyoverdine. The expression of fpvB is induced by iron limitation in Casamino acids (CAA) and in M9-glucose medium, but, unlike fpvA, not in a complex deferrated medium containing glycerol as carbon source. The fpvB gene was also detected in other P. aeruginosa isolates, including strains producing type II and type III pyoverdines. Inactivation of the fpvB homologues in these strains impaired their capacity to utilize type I ferripyoverdine as a source of iron. Accordingly, introduction of fpvB in trans restored the capacity to utilize type I ferripyoverdine.