...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of bacteriology >A Single Nucleotide Exchange in the wzy Gene Is Responsible for the Semirough O6 Lipopolysaccharide Phenotype and Serum Sensitivity of Escherichia coli Strain Nissle 1917
【24h】

A Single Nucleotide Exchange in the wzy Gene Is Responsible for the Semirough O6 Lipopolysaccharide Phenotype and Serum Sensitivity of Escherichia coli Strain Nissle 1917

机译：wzy基因中的单个核苷酸交换对大肠杆菌菌株Nissle 1917的半粗糙O6脂多糖表型和血清敏感性负责

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Structural analysis of lipopolysaccharide (LPS) isolated from semirough, serum-sensitive Escherichia coli strain Nissle 1917 (DSM 6601, serotype O6:K5:H1) revealed that this strain's LPS contains a bisphosphorylated hexaacyl lipid A and a tetradecasaccharide consisting of one E. coli O6 antigen repeating unit attached to the R1-type core. Configuration of the GlcNAc glycosidic linkage between O-antigen oligosaccharide and core (β) differs from that interlinking the repeating units in the E. coli O6 antigen polysaccharide (α). The wa? and wb? gene clusters of strain Nissle 1917, required for LPS core and O6 repeating unit biosyntheses, were subcloned and sequenced. The DNA sequence of the wa? determinant (11.8 kb) shows 97% identity to other R1 core type-specific wa? gene clusters. The DNA sequence of the wb? gene cluster (11 kb) exhibits no homology to known DNA sequences except manC and manB. Comparison of the genetic structures of the wb?O6 (wb? from serotype O6) determinants of strain Nissle 1917 and of smooth and serum-resistant uropathogenic E. coli O6 strain 536 demonstrated that the putative open reading frame encoding the O-antigen polymerase Wzy of strain Nissle 1917 was truncated due to a point mutation. Complementation with a functional wzy copy of E. coli strain 536 confirmed that the semirough phenotype of strain Nissle 1917 is due to the nonfunctional wzy gene. Expression of a functional wzy gene in E. coli strain Nissle 1917 increased its ability to withstand antibacterial defense mechanisms of blood serum. These results underline the importance of LPS for serum resistance or sensitivity of E. coli.
机译：从半粗糙，对血清敏感的大肠杆菌（Escherichia coli）Nissle 1917（DSM 6601，血清型O6：K5：H1）分离的脂多糖（LPS）的结构分析表明，该菌株的LPS包含双磷酸化的六酰基脂质A和a十四糖由一个 E 组成。 coli O6抗原重复单元附着在R1型核心上。 O抗原寡糖和核心（β）之间GlcNAc糖苷键的构型与 E 中重复单元的互连构型不同。 大肠杆菌 O6抗原多糖（α）。 LPS核心和O6重复单元生物合成所需的Nissle 1917菌株的 wa？和 wb？基因簇被亚克隆和测序。 wa？决定簇的DNA序列（11.8 kb）与其他R1核心类型特异性的 wa？基因簇具有97％的同一性。 wb？基因簇的DNA序列（11 kb）除 manC 和 manB 外与已知的DNA序列没有同源性。 Nissle 1917菌株 wb？ O6 （来自血清型O6的 wb？）决定子以及对光滑和抗血清的遗传结构的比较尿毒症 E 。 coli O6菌株536表明，编码Nissle 1917菌株的O-抗原聚合酶Wzy的推定开放阅读框由于点突变而被截短。与功能性 E 的 wzy 副本互补。 coli 菌株536证实了Nissle 1917菌株的半粗糙表型是由于无功能的 wzy 基因引起的。功能性 wzy 基因在 E 中的表达。 coli 菌株Nissle 1917增强了其抵抗血清抗菌防御机制的能力。这些结果强调了脂多糖对血清抗性或 E 敏感性的重要性。 大肠杆菌。

著录项

相似文献

  • 外文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号