Characterization of receptors of the bacterial signaling molecule autoinducer-2

细菌信号分子 autoinducer-2 受体的表征

• 批准号: 7365410
• 负责人: Stephen T. Miller
• 金额: $ 19.84万
• 依托单位: SWARTHMORE COLLEGE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7365410
• 关键词: Agonist; Bacillus anthracis; Bacillus cereus; Bacteria; Behavior; Binding; Biochemical; Bioinformatics; Biological Assay; Bioluminescence; Cell Communication; Cell Density; Cells; Chemicals; Communication; Complex; Detection; Enterobacter; Environment; Enzymes; Equilibrium; Gene Expression; Gene Expression Regulation; Genes; Genomics; Human; Knowledge; Ligand Binding; Mediating; Methods; Microbial Biofilms; Molecular; Monitor; Mutagenesis; Names; Nature; Population; Process; Production; Protein Overexpression; Proteins; Pseudomonas aeruginosa; Range; Reaction; Research; Roentgen Rays; Salmonella typhimurium; Sequence Analysis; Signal Transduction; Signaling Molecule; Sinorhizobium meliloti; Structure; VAI-2; Vibrio; Vibrio cholerae; Virulence; Work; Yersinia pestis; base; cell motility; design; novel; pathogen; quorum sensing; receptor; response

DESCRIPTION (provided by applicant): Bacteria communicate through a process known as quorum sensing, in which small chemical signals are produced and released into the environment. As the population increases, these signals (called autoinducers) accumulate and, when they reach sufficient concentration, are detected by other bacteria. Bacteria modulate gene expression in response to these signals, and thus are able to regulate their behavior in a population-wide manner [1-8]. Many important behaviors are regulated by quorum sensing, including virulence, motility, and biofilm formation [9-11, 13]. While most autoinducers mediate communication within a given bacterial species, a novel signal molecule, termed autoinducer-2 (AI-2), appears to be a universal signal molecule, facilitating signaling between species [6, 19]. More than 55 species of bacteria are known to carry the gene for LuxS, the AI-2 synthase, including pathogens such as Salmonella typhimurium, Bacillus anthracis, Yersinia pestis, and Vibrio cholerae [20]. Thus, AI-2 mediated quorum sensing offers a possible mechanism for controlling bacterial behavior of significant human pathogens [29, 30, 50-53]. Knowledge of the chemical identity of AI-2 is essential for the design of agonists and antagonists of quorum sensing, but previous work has shown that two different bacterial species recognize chemically distinct forms of AI-2 [24, 32]. Thus, it is crucial to identify AI-2 receptors in a given species and characterize AI-2 in the context of its receptor. This work seeks to both extend the set of known AI-2 receptors and determine the chemical form of AI-2 recognized by biomedically relevant bacterial species. Candidate AI-2 receptors will be identified in several bacterial species, including Bacillus cereus, Enterobacter sp. 638, Sinorhizobium meliloti and Pseudomonas aeruginosa, through genomic analysis including sequence similarity searches and fold prediction. These candidate proteins will be cloned, overexpressed, purified, and assayed for AI-2 binding via a Vibrio harveyi bioluminescence assay. Once AI-2 receptors have been identified biochemically, they will be further purified and crystallized. X-ray structures will be determined for AI-2/receptor complexes, allowing characterization of the chemical form of AI- 2 recognized by a particular species.

描述（由申请人提供）：细菌通过称为群体感应的过程进行交流，其中产生微小的化学信号并将其释放到环境中。随着种群数量的增加，这些信号（称为自诱导剂）会积累，当它们达到足够的浓度时，就会被其他细菌检测到。细菌响应这些信号调节基因表达，因此能够在群体范围内调节其行为[1-8]。许多重要的行为都受到群体感应的调节，包括毒力、运动性和生物膜形成 [9-11, 13]。虽然大多数自诱导剂介导特定细菌物种内的通讯，但一种称为自诱导剂-2 (AI-2) 的新型信号分子似乎是一种通用信号分子，可促进物种之间的信号传导 [6, 19]。已知超过 55 种细菌携带 LuxS（AI-2 合酶）基因，包括鼠伤寒沙门氏菌、炭疽杆菌、鼠疫耶尔森氏菌和霍乱弧菌等病原体 [20]。因此，AI-2 介导的群体感应为控制重要人类病原体的细菌行为提供了一种可能的机制 [29,30,50-53]。了解 AI-2 的化学特性对于设计群体感应的激动剂和拮抗剂至关重要，但之前的工作表明，两种不同的细菌物种识别化学上不同形式的 AI-2 [24, 32]。因此，识别给定物种中的 AI-2 受体并在其受体的背景下表征 AI-2 至关重要。这项工作旨在扩展已知的 AI-2 受体集，并确定生物医学相关细菌物种识别的 AI-2 的化学形式。候选 AI-2 受体将在几种细菌物种中被鉴定，包括蜡状芽孢杆菌、肠杆菌属。 638、苜蓿中华根瘤菌和铜绿假单胞菌，通过基因组分析（包括序列相似性搜索和倍数预测）。这些候选蛋白将被克隆、过表达、纯化，并通过哈维弧菌生物发光测定来测定 AI-2 的结合。一旦AI-2受体被生化鉴定，它们将被进一步纯化和结晶。将确定 AI-2/受体复合物的 X 射线结构，从而能够表征特定物种识别的 AI-2 的化学形式。

项目成果

Sinorhizobium meliloti, a bacterium lacking the autoinducer-2 (AI-2) synthase, responds to AI-2 supplied by other bacteria.

• DOI: 10.1111/j.1365-2958.2008.06477.x
• 发表时间: 2008-12
• 期刊: Molecular microbiology
• 影响因子: 3.6
• 作者: Pereira CS;McAuley JR;Taga ME;Xavier KB;Miller ST
• 通讯作者: Miller ST