Structural studies of biomolecules related to cancer and HIV-AIDS

与癌症和艾滋病相关的生物分子的结构研究

• 批准号: 10262780
• 负责人: Hiroshi Matsuo
• 金额: $ 66.17万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10262780
• 关键词: AIDS/HIV problem; APOCEC3G gene; Acquired Immunodeficiency Syndrome; Amino Acids; Binding; Catalytic Domain; Complex; Conflict (Psychology); Cryoelectron Microscopy; Cytosine deaminase; DNA; Deamination; Defense Mechanisms; Electron Microscopy; Epitopes; Goals; HIV; HIV Genome; HIV-1; Human; Infection; Magnetism; Malignant Neoplasms; Mutate; Nuclear; Pathway interactions; Proteins; RNA; Research; Research Project Grants; Signal Transduction; Single-Stranded DNA; Spectrum Analysis; Structural Protein; Structure; Techniques; Ubiquitin; Virion; X-Ray Crystallography; molecular dynamics; multicatalytic endopeptidase complex; novel therapeutics; pathogen; protein structure; ubiquitin-protein ligase

APOBEC3G (A3G) is a single-stranded DNA cytosine deaminase that can restrict HIV-1 infection by mutating HIV-1 genome. HIV-1 developed a counter defense mechanism by which virion infectivity factor (Vif) leads the degradation of A3G through ubiquitin-proteasome pathway. Our ultimate goal is to generate small compounds which inhibit the degradation of A3G. We have determined structures of two functional domains of A3G, including the VIf-binding domain and the catalytic domain. In addition, we have determined co-srystal structure of the A3G catalytic domain-ssDNA complex. By using NMR and Molecular Dynamics simulations, we revealed the mechanism by which APOBEC3 proteins exclude RNA as a substrate for deamination. We have assigned NMR signals of Vif, and identified amino acid residues in the interfaces with A3G. We are determining the structure of the A3G-Vif E3 ubiquitin ligase complex, which will provide epitopes to be targeted by small compounds which inhibit formation of the complex. We are using cryoEM/cryoET to determine the structure of the A3G-Vif E3 ubiquitin ligase complex.

APOBEC3G（A3G）是一种单链DNA胞嘧啶脱氨酶，可以通过突变HIV-1基因组来限制HIV-1感染。 HIV-1开发了一种反式机制，通过该机制，病毒体感染因子（VIF）通过泛素 - 蛋白酶体途径导致A3G降解。我们的最终目标是产生抑制A3G降解的小化合物。我们已经确定了A3G两个功能域的结构，包括VIF结合域和催化域。另外，我们确定了A3G催化结构域-SSDNA复合物的共晶结构。通过使用NMR和分子动力学模拟，我们揭示了APOBEC3蛋白将RNA排除RNA作为脱氨酸的底物的机制。我们已经分配了VIF的NMR信号，并鉴定出具有A3G的界面中的氨基酸残基。我们正在确定A3G-VIF E3泛素连接酶复合物的结构，该结构将提供由抑制复合物形成的小化合物靶向的表位。我们正在使用冷冻/冷冻物来确定A3G-VIF E3泛素连接酶复合物的结构。