SAXS STUDY OF NUCLEOTIDE-DEPENDENT CONFORMATIONAL CHANGE IN AB-TUBULIN AND HSP90

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 AB-微管蛋白和分子伴侣HSP90在真核细胞的生命过程中具有重要的非重叠作用。这两种蛋白质都能结合和水解核苷酸三磷酸(GTP用于微管蛋白，ATP用于HSP90)，并且已知采用多种构象，作为其功能循环的一部分。然而，目前尚不清楚这些构象变化是直接作为核苷酸状态的函数，还是蛋白质：蛋白质相互作用的结果(在HSP90的情况下，抗体-微管蛋白自组装成微管，底物/辅助伴侣结合)。研究这两种不同蛋白质的构象如何对核苷酸状态作出反应，将是形成对其功能的有意义的机制理解的必要的第一步。我们建议使用小角X射线散射(SAXS)来测量作为核苷酸状态函数的散射分布，从而获得对这些蛋白质构象偏好的任何潜在变化的重要结构洞察。

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. Ab-tubulin and the molecular chaperone HSP90 have essential non-overlapping roles in the life of eukaryotic cells. Both proteins bind and hydrolyze nucleotide triphosphates (GTP for tubulin, ATP for HSP90), and are known to adopt multiple conformations, as part of their functional cycle. It is not known, however, whether these conformational changes arise directly as a function of nucleotide state, or instead as a result of protein:protein interactions (self-assembly into microtubules for Ab-tubulin, substrate/co-chaperone binding in the case of HSP90). Studying how the conformations these of two different proteins respond to nucleotide state will be an essential first step in formulating a meaningful mechanistic understanding of their function. We propose to use small-angle X-ray scattering (SAXS) to measure scattering profiles as a function of nucleotide state, and thereby obtain vital structural insight into any potential changes in the conformational preferences of these proteins.