• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Infection and immunity >The Actinobacillus actinomycetemcomitans Ribose Binding Protein RbsB Interacts with Cognate and Heterologous Autoinducer 2 Signals
【24h】

The Actinobacillus actinomycetemcomitans Ribose Binding Protein RbsB Interacts with Cognate and Heterologous Autoinducer 2 Signals

机译：放线杆菌Actinomycetemcomitans核糖结合蛋白RbsB与同源和异源自诱导剂2信号相互作用。

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

摘要

Autoinducer 2 (AI-2) produced by the oral pathogen Actinobacillus actinomycetemcomitans influences growth of the organism under iron limitation and regulates the expression of iron uptake genes. However, the cellular components that mediate the response of A. actinomycetemcomitans to AI-2 have not been fully characterized. Analysis of the complete genome sequence of A. actinomycetemcomitans (www.oralgen.lanl.gov) indicated that the RbsB protein was related to LuxP, the AI-2 receptor of Vibrio harveyi. To determine if RbsB interacts with AI-2, the bioluminescence of the reporter strain V. harveyi BB170 (sensor 1?, sensor 2+) was determined after stimulation with partially purified AI-2 from A. actinomycetemcomitans or conditioned medium from V. harveyi cultures in the presence and absence of purified six-His-tagged RbsB. RbsB efficiently inhibited V. harveyi bioluminescence induced by both A. actinomycetemcomitans AI-2 and V. harveyi AI-2 in a dose-dependent manner, suggesting that RbsB competes with LuxP for AI-2. Fifty percent inhibition occurred with approximately 0.3 nM RbsB for A. actinomycetemcomitans AI-2 and 15 nM RbsB for V. harveyi AI-2. RbsB-mediated inhibition of V. harveyi bioluminescence was reversed by the addition of 50 mM ribose, suggesting that A. actinomycetemcomitans AI-2 and ribose bind at the same site of RbsB. The RbsB/AI-2 complex was thermostable since A. actinomycetemcomitans AI-2 could not be recovered by heating. This was not due to heat inactivation of A. actinomycetemcomitans AI-2 since signal activity was unaffected by heating in the absence of RbsB. Furthermore, an isogenic A. actinomycetemcomitans mutant that was unable to express rbsB was deficient in depleting A. actinomycetemcomitans AI-2 from solution relative to the wild-type organism. Inactivation of rbsB also influenced the ability of the organism to grow under iron-limiting conditions. The mutant strain attained a cell density of approximately 30% that of the wild-type organism under iron limitation. In addition, real-time PCR showed that the expression of afuABC, encoding a major ferric ion transporter, was reduced by approximately eightfold in the rbsB mutant. This phenotype was similar to that of a LuxS-deficient mutant of A. actinomycetemcomitans that is unable to produce AI-2. Together, our results suggest that RbsB may play a role in the response of A. actinomycetemcomitans to AI-2.
机译：口腔病原菌放线放线杆菌（Actinobacillus actinomycetemcomitans）产生的自诱导物2（AI-2）在铁限制下影响生物的生长并调节铁摄取基因的表达。但是，介导 A响应的细胞成分。 AI-2的放线放线菌尚未完全鉴定。分析 A的完整基因组序列。放线菌（Cominomycetemcomitans）（www.oralgen.lanl.gov）表明，RbsB蛋白与 Harveyi弧菌的AI-2受体LuxP有关。为了确定RbsB是否与AI-2相互作用，报道菌株 V的生物发光。在用来自 A的部分纯化的AI-2刺激后，测定harveyi BB170（传感器1′，传感器2+）。放线菌或 V条件培养基。 Harveyi培养基中是否存在纯化的带有六组His标签的RbsB。 RbsB有效抑制了 V。两种 A诱导的harveyi 生物发光。放线菌 AI-2和 V。 harveyi AI-2呈剂量依赖性，表明RbsB与LuxP竞争AI-2。 50％的抑制作用发生在 A区域，约为0.3 nM RbsB。放线放线菌 AI-2和 V的15 nM RbsB。 harveyi AI-2。 RbsB介导的 V抑制。加入50 mM核糖可逆转哈维（Harveyi）的生物发光，表明 A。放线菌（Cominomycetemcomitans） AI-2和核糖结合在RbsB的同一位点。自从 A以来，RbsB / AI-2复合物是热稳定的。放热放线杆菌 AI-2无法通过加热回收。这不是由于 A的热失活。放线放线菌 AI-2，因为在不存在RbsB的情况下加热不会影响信号活性。此外，同基因的 A。无法表达 rbsB 的放线放线菌突变体缺乏消耗 A的能力。相对于野生型生物体，来自溶液放线菌 AI-2。 rbsB 的失活也影响了生物在铁限制条件下生长的能力。在铁限制条件下，该突变菌株的细胞密度约为野生型生物的30％。另外，实时PCR显示， rbsB 突变体中编码主要铁离子转运蛋白的 afuABC 的表达降低了约八倍。该表型与 A的LuxS缺陷型突变体的表型相似。不能产生AI-2的放线菌科。在一起，我们的结果表明RbsB可能在 A的响应中发挥作用。放线菌对AI-2的作用。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 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