NUCLEOTIDE-DEPENDENT CONFORMATIONAL CHANGE IN ALPHA/BETA-TUBULIN & HSP90

α/β-微管蛋白中核苷酸依赖性构象变化

• 批准号: 7369144
• 负责人: DAVID A. AGARD
• 金额: $ 1.78万
• 依托单位: ILLINOIS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7369144
• 关键词: NUCLEOTIDE; DEPENDENT; CONFORMATIONAL; CHANGE; ALPHA

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. alpha/beta-Tubulin and the molecular chaperone Hsp90 have essential, non-overlapping roles in the life of eukaryotic cells. Both proteins bind and hydrolyze nucleoside triphosphates (GTP for tubulin, ATP for HSP90), and adopt multiple conformations as part of their functional cycle. Recent crystallographic results from the Agard lab have provided new insights into the role of conformational change in these proteins. We determined the structure of gamma-tubulin bound to GTP. Surprisingly, the conformation we observed was essentially identical to what was thought to be the GDP-bound conformation of the closely related alpha/beta-tubulin. Our structure of gamma-tubulin (together with biochemical data) suggests that conformational switching in tubulins is largely independent of nucleotide state. We also determined two structures of the E. coli Hsp90 homolog, HtpG, revealing dramatically different conformations that likely represent important functional states. Small angle X-ray scattering (SAXS) is the highest resolution solution technique capable of reporting on the conformational state of molecular assemblies, and is providing unique structural insight into conformational changes in these proteins. In particular, studying how (or whether) the conformations of these two different proteins respond to nucleotide state is an essential first step in formulating a meaningful mechanistic understanding of their function.

该子项目是利用 NIH/NCRR 资助的中心拨款提供的资源的众多研究子项目之一。子项目和研究者 (PI) 可能已从另一个 NIH 来源获得主要资金，因此可以在其他 CRISP 条目中得到体现。列出的机构是中心的机构，不一定是研究者的机构。 α/β-微管蛋白和分子伴侣 Hsp90 在真核细胞的生命中具有重要的、不重叠的作用。两种蛋白质均结合并水解三磷酸核苷（微管蛋白为 GTP，HSP90 为 ATP），并采用多种构象作为其功能循环的一部分。 Agard 实验室最近的晶体学结果为这些蛋白质中构象变化的作用提供了新的见解。我们确定了与 GTP 结合的 γ-微管蛋白的结构。令人惊讶的是，我们观察到的构象与密切相关的 α/β-微管蛋白的 GDP 结合构象本质上相同。我们的γ-微管蛋白结构（连同生化数据）表明微管蛋白的构象转换在很大程度上独立于核苷酸状态。我们还确定了大肠杆菌 Hsp90 同源物 HtpG 的两种结构，揭示了可能代表重要功能状态的显着不同的构象。小角 X 射线散射 (SAXS) 是能够报告分子组装体构象状态的最高分辨率解决方案技术，并为这些蛋白质的构象变化提供独特的结构洞察。特别是，研究这两种不同蛋白质的构象如何（或是否）响应核苷酸状态是对其功能形成有意义的机制理解的重要第一步。