The impact of iron acquisition systems in Yersinia virulence.

铁的供应是病原菌成功存活和有效传播的先决条件。致病性耶尔森氏菌具有多种铁转运系统，但只有一个单一的内源性耶尔森氏杆菌素铁载体（Ybt）生物合成系统。然而，并非所有高致病性耶尔森菌都使用耶尔森菌素。几乎一半的Y。假结核O：3菌株不具有Ybt，但显示铁载体活性。利用基因组消减杂交，我们证明，yptb 3290-yptb 3298集群可能是负责生产这种铁载体命名为pseudochelin（Pch）。为了证明pch基因在铁载体产生中的影响，我们在铁载体阳性的Y中灭活了一个潜在的铁载体生物合成基因yptb 3297。假结核O型3例。构建的突变体没有表现出铁结合活性，但在长时间培养后仍然可以检测到相对较低的铁载体活性。在Y.鼠疫菌被命名为耶尔森氏菌（Ych）。我们建议，ysu基因簇（耶尔森氏菌铁载体摄取）是负责耶尔森氏菌achelin生产。为了解决这两个未知的铁载体的性质和它们在耶尔森氏菌致病性中的作用，我们正在构建一个单独的铁载体系统和双突变体的突变体面板。pseudochelin和yersiniachelin铁载体已被纯化和生化表征，其结构将被确定。杂环pseudochelin的分子量为406 Da，而异羟肟酸耶尔森氏菌属是610 Da。我们想解决的作用pseudochelin和耶尔森氏菌属铁载体在铁的收购，致病性和健身，以及阐明它们的位置在一个层次结构的铁收购系统在耶尔森氏菌。

Iron supply is a prerequisite for successful survival and efficient dissemination of pathogenic bacteria. The pathogenic Yersinia possess several iron transport systems but only a single endogenous yersiniabactin siderophore (Ybt) biosynthetic system. However, not all highly-pathogenic yersiniae use yersiniabactin. Nearly half of Y. pseudotuberculosis O:3 strains do not possess Ybt but display siderophore activity. Using genomic subtractive hybridization we demonstrated that the yptb3290-yptb3298 cluster might be responsible for production of this siderophore designated as pseudochelin (Pch). To prove the impact of the pch genes in siderophore production we inactivated a potential siderophore biosynthetic gene yptb3297 in the siderophore-positive Y. pseudotuberculosis O:3. The constructed mutant demonstrated no iron binding activity however relatively low siderophore activity can still be detected after prolonged cultivation. This residual siderophore activity also detected in Y. pestis was designated as yersiniachelin (Ych). We propose that the ysu gene cluster (Yersinia siderophore uptake) is responsible for yersiniachelin production. To address the nature of these two uncharacterized siderophores and their role in Yersinia pathogenicity we are constructing a panel of mutants in individual siderophore systems and double mutants. The pseudochelin and yersiniachelin siderophores have been purified and characterized biochemically and their structures will be determined. The molecular mass of the heterocyclic pseudochelin is 406 Da, while hydroxamate yersiniachelin is 610 Da. We would like to address the role of pseudochelin and yersiniachelin siderophores in iron acquisition, pathogenicity and fitness as well as to elucidate their place in a hierarchy of iron acquisition systems in Yersinia.