Role of a novel auto-protease domain in antibacterial toxin delivery

新型自体蛋白酶结构域在抗菌毒素递送中的作用

• 批准号: 10372140
• 负责人: Celia Goulding
• 金额: $ 19.53万
• 依托单位: UNIVERSITY OF CALIFORNIA SANTA BARBARA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-15 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10372140
• 关键词: Acinetobacter; Amino Acid Sequence; Anti-Bacterial Agents; Architecture; Asparagine; Bacteria; Bacterial Genome; Binding; Biochemical; Biochemistry; Burkholderia; C-terminal; Cell surface; Cells; Chimera organism; Complex; Crystallization; Crystallography; Cytoplasm; Cytosol; Databases; Engineering; Enterobacteriaceae; Environment; Escherichia coli; Family; Gene Cluster; Gram-Negative Bacteria; Growth; Immunity; Individual; LYN gene; Left; Lyase; Mediating; Membrane; Microbe; Modeling; Molecular; Molecular Genetics; Mutate; Neisseria; Pathway interactions; Peptide Hydrolases; Peptides; Protease Domain; Protein Secretion; Proteins; Pseudomonas; Reporting; Research; Role; Siblings; Site-Directed Mutagenesis; Structural Models; Structure; System; Testing; Thin Filament; Toxin; Vertebral column; Work; antimicrobial; functional plasticity; human pathogen; inhibitor; insight; new technology; novel; novel strategies; pathogen; pathogenic bacteria; periplasm; protein aminoacid sequence; receptor; receptor binding; structural biology

Project summary Contact-dependent growth inhibition (CDI) is an important mechanism of inter-bacterial competition found in a wide variety of Gram-negative bacteria, including many important human pathogens. CDI is mediated by the CdiB/CdiA family of two-partner secretion proteins, which are thought to assemble as a binary complex on the cell surface. CdiA forms a thin filament to projects away from the inhibitor cell to bind to receptors on susceptible bacteria. After binding receptor, CdiA delivers its C-terminal toxin domain (CdiA-CT) into the target cell. CDI systems also encode CdiI immunity proteins, which specifically bind to the CdiA-CT and neutralize toxin activity to protect the cell from auto-inhibition. CdiA-CT/CdiI sequences are extraordinarily variable, with >130 distinct toxin/immunity protein sequence types recognized in bacterial genomes. CdiA-CT toxins are modular and can be exchanged between CdiA proteins to generate functional chimeras. These observations indicate that many different kinds of toxic cargo can be delivered into the cytoplasm of target bacteria. This application seeks to determine the molecular and structural underpinnings that enable this remarkable functional plasticity. We will use a combination of molecular genetic, biochemical and structural approaches to gain insight into the functional interactions between the constituent domains of CdiA. This research will significantly increase our mechanistic understanding of CdiA function and could inform novel strategies for antimicrobial therapy.

项目概要 接触依赖性生长抑制（CDI）是细菌间竞争的重要机制 存在于多种革兰氏阴性细菌中，包括许多重要的人类病原体。 CDI 是 由双伙伴分泌蛋白的 CdiB/CdiA 家族介导，这些蛋白被认为以二元形式组装 细胞表面的复合物。 CdiA 形成细丝，远离抑制剂细胞，与 敏感细菌上的受体。结合受体后，CdiA 传递其 C 端毒素结构域 (CdiA-CT) 进入目标细胞。 CDI 系统还编码 CdiI 免疫蛋白，该蛋白特异性结合 CdiA-CT 并中和毒素活性以保护细胞免受自身抑制。 CdiA-CT/CdiI 序列非常出色 变量，具有细菌基因组中识别的超过 130 种不同的毒素/免疫蛋白序列类型。 CdiA-CT 毒素是模块化的，可以在 CdiA 蛋白之间交换以产生功能性嵌合体。这些 观察表明，许多不同种类的有毒货物可以被递送到目标的细胞质中 细菌。该应用旨在确定实现这一目标的分子和结构基础 显着的功能可塑性。我们将结合分子遗传学、生化和结构 深入了解 CdiA 组成域之间功能相互作用的方法。这 研究将显着增加我们对 CdiA 功能的机制理解，并可为新的研究提供信息 抗菌治疗策略。