Mycobacterium Tuberculosis Cell Wall Assembly

结核分枝杆菌细胞壁组装

• 批准号: 9089894
• 负责人: Mary Jackson
• 金额: $ 22.65万
• 依托单位: COLORADO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9089894
• 关键词: Actins; Address; Anabolism; Anti-Bacterial Agents; Antibiotics; Bacillus (bacterium); Bacillus subtilis; Bacteria; Biochemical; Biological Assay; Cell Wall; Cell division; Cells; Chemistry; Collaborations; Colorado; Complex; Contracts; Corynebacterium glutamicum; Development; Enzymes; Family; Future; Gene Cluster; Genes; Genetic; Genome; Genus Mycobacterium; Gram-Positive Bacteria; Growth; Health; Homologous Gene; In Vitro; Incidence; Individual; Institutes; Japan; Knock-out; Knowledge; Ligase; Link; Maps; Mediating; Molecular; Multi-Drug Resistance; Muramidase; Mus; Mycobacterium tuberculosis; Mycobacterium tuberculosis H37Rv; N-acetylglucopyranosylamine; National Institute of Allergy and Infectious Disease; Parents; Pathway interactions; Peptidoglycan; Phenotype; Physiological; Physiological Processes; Physiology; Play; Predisposition; Proteins; Recombinants; Resistance; Role; Shapes; Site; Staphylococcus aureus; Structure; Teichoic Acids; Testing; Therapeutic; Therapeutic Studies; Tokyo; Transferase; Universities; Validation; Virulence; arabinogalactan; base; cell assembly; cell envelope; design; in vitro Assay; in vivo; inhibitor/antagonist; innovation; inorganic phosphate; insight; knock-down; lipoteichoic acid; macromolecule; microbial; mutant; mycobacterial; novel; novel strategies; pathogen; permissiveness; programs; research study; resistant strain; retinal rods; scaffold; screening; translocase; tuberculosis drugs

 DESCRIPTION (provided by applicant): The cell envelope of Mycobacterium tuberculosis (Mtb) is the basis of many of the physiological and pathogenic features of this bacterial pathogen and the site of susceptibility and resistance to many anti- tuberculosis drugs. In spite of being Gram-positive bacteria, mycobacteria are unique in having a cell wall devoid of (lipo)teichoic acids and instead containing a heteropolysaccharide known as the arabinogalactan (AG) covalently attached to peptidoglycan (PG). To this date, the cell wall ligase(s) responsible for the covalent attachment of these two macromolecules has/have defied definition. Despite the fundamental structural differences that exist between AG and wall teichoic acids (WTA), the structure of the unit linking AG to PG in mycobacteria shares similarities with the linker involved in the covalent attachment of WTA to PG in many Gram-positive bacteria. Enzymes of the widespread LytR-Cps2A-Psr (LCP) family were recently identified as the likely ligases mediating WTA-PG attachment in Bacillus subtilis and Staphylococcus aureus. We identified three LCP-like proteins in the genome of Mtb H37Rv, one of them mapping to an AG biosynthetic gene cluster. We here propose to use a combination of genetic and biochemical approaches to determine whether these three LCP homologs are the long sought mycobacterial cell wall ligases and to define their therapeutic potential. In particula, we will test whether two novel antibacterial compounds, caprazamycin B and CPZEN-45, products of a collaboration with the Institute of Microbial Chemistry (BIKAKEN, Tokyo, Japan) that inhibit mechanistically similar enzymes in mycobacterial cell wall assembly (MraY and WecA, respectively) may represent promising scaffolds for the future development of inhibitors targeting the assembly of the mycobacterial cell wall. Similar to the situation with WTA ligases, i is likely that the ligase(s) of Mtb interact(s) with other wall proteins to coordinate cell wall synthesis with cell elongation and cell division. The characterization of Mtb's ligase(s) therefore also represents an important first step toward the elucidation of this key aspect of the physiology of mycobacteria and the future design of innovative therapeutic strategies aimed at targeting cell elongation and division.

 描述（由申请人提供）：结核分枝杆菌（Mtb）的细胞包膜是该细菌病原体的许多生理和致病特征的基础，也是对许多抗结核药物敏感和耐药的部位。尽管是革兰氏阳性细菌，但分枝杆菌的独特之处在于其细胞壁不含（脂）磷壁酸，而是含有共价连接至肽聚糖（PG）的称为阿拉伯半乳聚糖（AG）的杂多糖。迄今为止，负责这两种大分子共价连接的细胞壁连接酶尚未定义。尽管AG和壁磷壁酸（WTA）之间存在基本的结构差异，但分枝杆菌中连接AG与PG的单元的结构与许多革兰氏阳性细菌中参与WTA与PG共价连接的接头具有相似性。广泛分布的LytR-Cps 2A-Psr（LCP）家族的酶最近被鉴定为枯草芽孢杆菌和金黄色葡萄球菌中可能的介导WTA-PG附着的连接酶。我们在结核分枝杆菌H37 Rv基因组中鉴定了三种LCP样蛋白，其中一种定位于AG生物合成基因簇。在这里，我们建议使用遗传和生化方法的组合，以确定这三个LCP同系物是否是长期寻求分枝杆菌细胞壁连接酶，并确定其治疗潜力。特别是，我们将测试两种新的抗菌化合物，caprazamycin B和CPZEN-45，与微生物化学研究所（BIKAKEN，东京，日本）的合作产品，抑制分枝杆菌细胞壁组装（MraY和WecA，分别）的机制相似的酶，可能代表未来发展的抑制剂靶向分枝杆菌细胞壁的组装有前途的支架。与WTA连接酶的情况类似，Mtb的连接酶可能与其他壁蛋白相互作用以协调细胞壁合成与细胞伸长和细胞分裂。因此，Mtb连接酶的表征 也代表了阐明生理学的这一关键方面的重要的第一步 的分枝杆菌和未来的设计创新的治疗策略，旨在针对细胞的延伸和分裂。