Screening for Inhibitors of DNA Replication in Gram-Positive Bacteria

描述（由申请方提供）：使用模型革兰氏（+）微生物枯草芽孢杆菌，我们建议将MLPCN转移至一种靶向DNA聚合酶III全酶的稳健高通量筛选试验。通过筛选该靶标发现的小分子将使用适当的生物化学特异性和微生物活性测定优先选择具有开发成DNA复制途径的抗菌和步骤特异性干扰剂潜力的抑制剂。该模式生物与大多数常见的革兰氏（+）人类病原体密切相关，如S。aureus、S.化脓菌和生物防御A类生物炭疽杆菌。在过去的三十年中，FDA仅批准了两种新的化学类别的抗生素，并且人们普遍认为细菌对现有类别的抗生素的耐药性正在增加。目前，还没有针对细菌中DNA复制的基本过程的抗菌剂。 细菌DNA复制是由细胞复制酶，DNA聚合酶III全酶，具有复制整个染色体而不解离的持续合成能力。该过程使用至少5种不同的必需蛋白质和酶活性。这些蛋白质靶标和它们之间发生的必要相互作用为抗菌剂的开发提供了有吸引力的靶标，并且也将作为开发化学遗传方法以干扰各种相互作用和反应阶段的理想系统。 公共卫生相关性：在社区和医院环境中，细菌病原体对常用抗生素的耐药性越来越强，这代表着一个日益严重的公共卫生问题。这推动了研究的需要，以发现新的抗菌剂，影响未开发的目标，其中没有耐药性。这项工作将探索各种此类未开发的靶标，这些靶标对于与许多常见的人类病原菌密切相关的模式生物中的细菌DNA复制至关重要，这将有助于发现此类新的抗菌化合物。

DESCRIPTION (provided by applicant): Using a model Gram (+) organism, Bacillus subtilis, we propose to transfer to the MLPCN, a robust high throughput screening assay targeting the DNA Polymerase III holoenzyme. Small molecules discovered via screening of this target will be prioritized using appropriate biochemical specificity and microbiological activity assays to select inhibitors that have the potential to be developed into antibacterial and step-specific perturbants of DNA replication pathways. This model organism is closely related to most common Gram (+) human pathogens such as S. aureus, S. pyogenes and the biodefense category A organism, Bacillus anthracis. Over the last three decades only 2 new chemical classes of antibiotics have been approved by the FDA and it is widely recognized that bacterial resistance to existing classes of antibiotics is increasing. Presently there are no antibacterial targeting the essential process of DNA replication in bacteria. Bacterial DNA replication is performed by the cellular replicase, DNA polymerase III holoenzyme that has the processivity to replicate the entire chromosome without dissociation. This process employs at least 5 different essential proteins and enzymatic activities. These protein targets and the essential interactions that occur between them provide attractive targets for the development of antibacterial, and will also serve as an ideal system for developing chemical genetic approaches to perturb the various interactions and reaction stages. PUBLIC HEALTH RELEVANCE: Bacterial pathogens are increasingly becoming resistant to commonly used antibiotics in both community and hospital settings, representing a growing public health problem. This has driven the need for research to discover new antibacterial that affect unexploited targets for which resistance is absent. This work will explore a variety of such unexploited targets, essential for bacterial DNA replication in a model organism closely related to many common human pathogenic bacteria, which will aid the discovery of such new antibacterial compounds.