Development of Artificial Agonists for a Bacterial Riboswitch

细菌核糖开关人工激动剂的开发

• 批准号: 7247818
• 负责人: JULIANE K STRAUSS-SOUKUP
• 金额: $ 21.53万
• 依托单位: CREIGHTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7247818
• 关键词: Affect; Agonist; Amines; Antibiotic Resistance; Antibiotics; Bacteria; Bacterial Infections; Binding; Biochemical; Biological Assay; Catalysis; Catalytic RNA; Cell Wall; Class; Complex; Development; Elements; Feedback; Functional RNA; Gene Expression; Gene Expression Alteration; Genes; Genetic; Gram-Positive Bacteria; Grant; Growth; Hydrogen Bonding; In Vitro; Ions; Kinetics; Ligands; Maps; Measurement; Messenger RNA; Metabolic; Metabolic Pathway; Metabolism; Metals; Play; Process; RNA; Range; Rate; Regulation; Reporter; Resistance; Role; Structure; Today; Work; analog; antimicrobial drug; chemical group; design; fighting; functional group; glucosamine 6-phosphate; in vivo; inorganic phosphate; insight; interest; novel; novel strategies; nucleobase; nucleotide analog; pathogen; research study

DESCRIPTION (provided by applicant): The emergence of antibiotic resistance has required that new approaches be applied in order to effectively fight a host of medically relevant bacterial infections. The limited group of antibiotics, currently in use, need to be replaced with novel, rigorous, and safe treatments in order to combat the evolved bacterium of today. One way to destroy bacteria is to target one of their most essential processes, metabolism. The recent discovery of RNA structural elements, termed riboswitches, that bind cellular metabolites and control expression of essential metabolic genes provides a unique and distinct target for development of artificial agonists to fight bacterial infections. Riboswitches are found in non-coding regions of messenger RNAs, and gene expression is modulated when metabolite binds directly to the RNA. Many riboswitches repress expression of nearby genes involved in the synthesis of the metabolite, providing an efficient feedback mechanism of genetic control. One particular riboswitch (the glmS riboswitch) binds to glucosamine-6-phosphate (GlcN6P), a building block of the cell wall in Gram-positive bacteria, and undergoes self-cleavage resulting in inactivity of the mRNA. The amine functionality of GlcN6P seems to be directly involved in RNA catalysis, whereas the phosphate may play a role in recognition of the ligand by the RNA. In order to develop effective artificial agonists/antibiotics that target the glmS riboswitch, an understanding of the structural and functional details of the riboswitch-metabolite complex is essential. The aims of this grant focus on (1) investigating the structural and catalytic roles of metal ions in the glmS riboswitch, (2) deciphering ligand recognition by the glmS riboswitch, and (3) designing non-natural agonists with the ability to stimulate glmS riboswitch self-cleavage and control gene expression. Using Nucleotide Analog Interference Mapping and Suppression (NAIM and NAIS, respectively) some of the long range contacts between the glmS riboswitch, its ligand, and metal ions will be determined. Using NAIM, the biochemical contribution of a single chemical group within the glmS riboswitch will be defined using nucleotide analogs that modify the atom(s) of interest. Using NAIS, specific tertiary hydrogen bonding partners within or involving the glmS RNA structure will be determined. Structure-function studies of riboswitches will enable rational design of non-natural metabolite-like compounds that might function as agonists/antibiotics to halt bacterial growth through alteration of gene expression. The threat of bacterial infections due to lack of effective antibiotics has come to the forefront as these pathogens become resistant to almost every antibiotic available to the public. The need is great for new classes of anti-microbial agents that target different, but specific and essential, metabolic pathways, such as those which utilize riboswitches to control gene expression. Structure-function studies of riboswitches will enable rational design of non-natural agonists that ultimately could function as antibiotics.

描述（由申请人提供）：抗生素耐药性的出现要求采用新方法，以有效地抵抗许多医学相关的细菌感染。目前正在使用的抗生素有限的抗生素需要用新颖，严格和安全的治疗来代替，以便对抗当今的进化细菌。消灭细菌的一种方法是针对其最重要的过程之一，即代谢。最新发现的RNA结构元素称为核糖开关，结合细胞代谢物和基本代谢基因的控制表达为人工激动剂的发展提供了独特而独特的靶标，以抵抗细菌感染。核糖开关在信使RNA的非编码区域中发现，当代谢物直接与RNA结合时，基因表达会被调节。许多核糖开关抑制了代谢物合成的附近基因的表达，从而提供了有效的遗传控制反馈机制。一种特定的核糖开关（Glms Riboswitch）与革兰氏阳性细菌中细胞壁的构建块（GLCN6P）结合，葡萄糖胺-6-磷酸盐（GLCN6P），并经历自我裂解，导致mRNA不活跃。 GLCN6P的胺功能似乎直接参与RNA催化，而磷酸盐可能在RNA识别配体方面发挥作用。为了开发针对GLMS Riboswitch的有效人工激动剂/抗生素，了解核糖开关 - 米代谢物复合物的结构和功能细节是必不可少的。该赠款的目的是（1）研究金属离子在GLMS核糖开关中的结构和催化作用，（2）GLMS Riboswitch的识别配体识别，以及（3）设计非天然激动剂，具有刺激GLMS Riboswitch riboswitch的自我裂解和控制基因表达的能力。将使用核苷酸模拟干扰映射和抑制（分别为NAIM和NAI），将确定Glms Riboswitch，其配体和金属离子之间的一些远程接触。使用NAIM，将使用核苷酸类似物来定义GLMS核糖开关中单个化学基团的生化贡献，该核苷酸类似物改变了感兴趣的原子。使用NAI，将确定在或涉及GLMS RNA结构内的特定三级氢键伙伴。核糖开关的结构功能研究将使非天然代谢物样化合物的合理设计可能充当激动剂/抗生素，从而通过改变基因表达来阻止细菌生长。由于缺乏有效的抗生素，细菌感染的威胁已成为最前沿的，因为这些病原体几乎对公众可用的每种抗生素具有抗药性。需求非常适合针对不同但特定和必不可少的代谢途径的新类别的抗微生物剂，例如利用核糖开关来控制基因表达的途径。核糖开关的结构功能研究将使最终可以充当抗生素的非天然激动剂的合理设计。